MutatingScope.php

<?php declare(strict_types = 1);

namespace PHPStan\Analyser;

use PhpParser\Node;
use PhpParser\Node\Arg;
use PhpParser\Node\ComplexType;
use PhpParser\Node\Expr;
use PhpParser\Node\Expr\Array_;
use PhpParser\Node\Expr\ClassConstFetch;
use PhpParser\Node\Expr\ConstFetch;
use PhpParser\Node\Expr\FuncCall;
use PhpParser\Node\Expr\Match_;
use PhpParser\Node\Expr\MethodCall;
use PhpParser\Node\Expr\PropertyFetch;
use PhpParser\Node\Expr\Variable;
use PhpParser\Node\Identifier;
use PhpParser\Node\Name;
use PhpParser\Node\Name\FullyQualified;
use PhpParser\Node\PropertyHook;
use PhpParser\Node\Scalar;
use PhpParser\Node\Scalar\String_;
use PhpParser\Node\Stmt\ClassMethod;
use PhpParser\Node\Stmt\Function_;
use PhpParser\NodeFinder;
use PHPStan\Analyser\ExprHandler\Helper\ClosureTypeResolver;
use PHPStan\Analyser\Generics\ClosureSignatureInference;
use PHPStan\Analyser\Generics\TemplateArgumentConstraints;
use PHPStan\Analyser\Generics\TemplateArgumentFrame;
use PHPStan\Analyser\Traverser\TransformStaticTypeTraverser;
use PHPStan\Collectors\Collector;
use PHPStan\Node\EmitCollectedDataNode;
use PHPStan\Node\Expr\AlwaysRememberedExpr;
use PHPStan\Node\Expr\CloneReinitializationExpr;
use PHPStan\Node\Expr\IntertwinedVariableByReferenceWithExpr;
use PHPStan\Node\Expr\NativeTypeExpr;
use PHPStan\Node\Expr\OriginalForeachKeyExpr;
use PHPStan\Node\Expr\OriginalForeachValueExpr;
use PHPStan\Node\Expr\ParameterVariableOriginalValueExpr;
use PHPStan\Node\Expr\PropertyInitializationExpr;
use PHPStan\Node\Expr\SetExistingOffsetValueTypeExpr;
use PHPStan\Node\IssetExpr;
use PHPStan\Node\Printer\ExprPrinter;
use PHPStan\Node\VirtualNode;
use PHPStan\Php\PhpVersionFactory;
use PHPStan\Php\PhpVersions;
use PHPStan\PhpDoc\ResolvedPhpDocBlock;
use PHPStan\Reflection\Assertions;
use PHPStan\Reflection\AttributeReflection;
use PHPStan\Reflection\ClassConstantReflection;
use PHPStan\Reflection\ClassMemberReflection;
use PHPStan\Reflection\ClassReflection;
use PHPStan\Reflection\ExtendedMethodReflection;
use PHPStan\Reflection\ExtendedParametersAcceptor;
use PHPStan\Reflection\ExtendedPropertyReflection;
use PHPStan\Reflection\FunctionReflection;
use PHPStan\Reflection\InitializerExprContext;
use PHPStan\Reflection\MethodReflection;
use PHPStan\Reflection\ParameterReflection;
use PHPStan\Reflection\ParametersAcceptorSelector;
use PHPStan\Reflection\Php\PhpFunctionFromParserNodeReflection;
use PHPStan\Reflection\Php\PhpMethodFromParserNodeReflection;
use PHPStan\Reflection\PropertyReflection;
use PHPStan\ShouldNotHappenException;
use PHPStan\TrinaryLogic;
use PHPStan\Turbo\ShadowedByTurboExtension;
use PHPStan\Type\Accessory\AccessoryArrayListType;
use PHPStan\Type\Accessory\HasOffsetValueType;
use PHPStan\Type\Accessory\NonEmptyArrayType;
use PHPStan\Type\Accessory\OversizedArrayType;
use PHPStan\Type\ArrayType;
use PHPStan\Type\BenevolentUnionType;
use PHPStan\Type\ClosureType;
use PHPStan\Type\ConditionalTypeForParameter;
use PHPStan\Type\Constant\ConstantArrayTypeBuilder;
use PHPStan\Type\Constant\ConstantBooleanType;
use PHPStan\Type\Constant\ConstantFloatType;
use PHPStan\Type\Constant\ConstantIntegerType;
use PHPStan\Type\Constant\ConstantStringType;
use PHPStan\Type\ConstantTypeHelper;
use PHPStan\Type\ErrorType;
use PHPStan\Type\GeneralizePrecision;
use PHPStan\Type\Generic\TemplateTypeHelper;
use PHPStan\Type\Generic\TemplateTypeMap;
use PHPStan\Type\IntegerRangeType;
use PHPStan\Type\IntegerType;
use PHPStan\Type\IntersectionType;
use PHPStan\Type\MixedType;
use PHPStan\Type\NeverType;
use PHPStan\Type\NullType;
use PHPStan\Type\ObjectType;
use PHPStan\Type\StaticType;
use PHPStan\Type\StaticTypeFactory;
use PHPStan\Type\StringType;
use PHPStan\Type\ThisType;
use PHPStan\Type\Type;
use PHPStan\Type\TypeCombinator;
use PHPStan\Type\TypeTraverser;
use PHPStan\Type\TypeUtils;
use PHPStan\Type\TypeWithClassName;
use PHPStan\Type\UnionType;
use PHPStan\Type\VerbosityLevel;
use PHPStan\Type\VoidType;
use Serializable;
use Throwable;
use function abs;
use function array_filter;
use function array_key_exists;
use function array_keys;
use function array_last;
use function array_map;
use function array_merge;
use function array_pop;
use function array_shift;
use function array_slice;
use function array_values;
use function count;
use function ctype_alnum;
use function explode;
use function get_class;
use function implode;
use function in_array;
use function is_string;
use function ltrim;
use function md5;
use function min;
use function preg_match;
use function preg_match_all;
use function spl_object_id;
use function sprintf;
use function str_starts_with;
use function strlen;
use function strtolower;
use function substr;
use function uksort;
use function usort;
use const PHP_INT_MAX;
use const PHP_INT_MIN;

#[ShadowedByTurboExtension(implementation: __DIR__ . '/../../turbo-ext/src/MutatingScope.cpp')]
class MutatingScope implements Scope, NodeCallbackInvoker, CollectedDataEmitter, DependencyTracker
{

	private const COMPLEX_UNION_TYPE_MEMBER_LIMIT = 8;

	/** Distinct name/namespace combinations getGlobalConstantType() remembers the expression keys of. */
	private const GLOBAL_CONSTANT_FETCH_KEYS_LIMIT = 8192;

	/** Magic methods that let the author decide which properties survive a serialize()/unserialize() round trip. */
	private const CUSTOM_SERIALIZATION_METHODS = ['__sleep', '__serialize', '__unserialize'];

	/**
	 * Expression keys the constant-fetch nodes of a global constant lookup print
	 * as, by the name class, name and namespace they are built from. The nodes
	 * exist only to produce those keys, and a freshly built node can never hit
	 * the printer's node-attribute cache - so without this every lookup printed
	 * two or three of them again. PHP_VERSION_ID alone accounted for ~30% of all
	 * expression-key prints in a self-analysis run.
	 *
	 * @var array<string, list<string>>
	 */
	private static array $globalConstantFetchKeys = [];

	/**
	 * @internal accessed by ScopeOps (native and PHP implementations)
	 * @var array<string, Type>
	 */
	public array $resolvedTypes = [];

	private ?self $nodeCallbackScope = null;

	/** @var non-empty-string|null */
	private ?string $namespace;

	private ?self $scopeOutOfFirstLevelStatement = null;

	private ?self $scopeWithPromotedNativeTypes = null;

	/**
	 * @param array<string, ExpressionTypeHolder> $expressionTypes
	 * @param array<string, ConditionalExpressionHolder[]> $conditionalExpressions
	 * @param list<non-empty-string> $inClosureBindScopeClasses
	 * @param array<string, bool> $currentlyAssignedExpressions true when the expression is a plain write target (its writable type applies), false when it is read-modified in place (e.g. the base of `$prop[] = ...`), where its readable type applies
	 * @param array<string, true> $currentlyAllowedUndefinedExpressions
	 * @param array<string, ExpressionTypeHolder> $nativeExpressionTypes
	 * @param list<array{MethodReflection|FunctionReflection|null, ParameterReflection|null}> $inFunctionCallsStack
	 */
	public function __construct(
		private ScopeServices $services,
		protected InternalScopeFactory $scopeFactory,
		protected ScopeContext $context,
		private bool $declareStrictTypes = false,
		private PhpFunctionFromParserNodeReflection|null $function = null,
		?string $namespace = null,
		public array $expressionTypes = [],
		protected array $nativeExpressionTypes = [],
		protected array $conditionalExpressions = [],
		protected array $inClosureBindScopeClasses = [],
		private ?ClosureType $anonymousFunctionReflection = null,
		private bool $inFirstLevelStatement = true,
		protected array $currentlyAssignedExpressions = [],
		protected array $currentlyAllowedUndefinedExpressions = [],
		public array $inFunctionCallsStack = [],
		protected bool $afterExtractCall = false,
		private ?self $parentScope = null,
		public bool $nativeTypesPromoted = false,
		protected ?TemplateArgumentFrame $templateArgumentFrame = null,
		protected ?TemplateArgumentConstraints $templateArgumentConstraints = null,
	)
	{
		if ($namespace === '') {
			$namespace = null;
		}

		$this->namespace = $namespace;
	}

	public function toNodeCallbackScope(): self
	{
		if ($this->nodeCallbackScope !== null) {
			return $this->nodeCallbackScope;
		}

		$nodeCallbackScope = $this->scopeFactory->toNodeCallbackScopeFactory()->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
		if ($nodeCallbackScope instanceof NodeCallbackScope) {
			$nodeCallbackScope->seedWalkScope($this);
		}

		return $this->nodeCallbackScope = $nodeCallbackScope;
	}

	public function toWalkScope(): self
	{
		return $this;
	}

	/** @deprecated */
	public function toMutatingScope(): self
	{
		return $this;
	}

	/** @api */
	public function getFile(): string
	{
		return $this->context->getFile();
	}

	/** @api */
	public function getFileDescription(): string
	{
		if ($this->context->getTraitReflection() === null) {
			return $this->getFile();
		}

		/** @var ClassReflection $classReflection */
		$classReflection = $this->context->getClassReflection();

		$className = $classReflection->getDisplayName();
		if (!$classReflection->isAnonymous()) {
			$className = sprintf('class %s', $className);
		}

		$traitReflection = $this->context->getTraitReflection();
		if ($traitReflection->getFileName() === null) {
			throw new ShouldNotHappenException();
		}

		return sprintf(
			'%s (in context of %s)',
			$traitReflection->getFileName(),
			$className,
		);
	}

	/** @api */
	public function isDeclareStrictTypes(): bool
	{
		return $this->declareStrictTypes;
	}

	public function enterDeclareStrictTypes(): self
	{
		return $this->scopeFactory->create(
			$this->context,
			true,
			null,
			null,
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	/**
	 * @param array<string, ExpressionTypeHolder> $currentExpressionTypes
	 * @return array<string, ExpressionTypeHolder>
	 */
	private function rememberConstructorExpressions(array $currentExpressionTypes): array
	{
		$rememberPropertyState = !$this->classHasCustomSerialization();
		$expressionTypes = [];
		foreach ($currentExpressionTypes as $exprString => $expressionTypeHolder) {
			$expr = $expressionTypeHolder->getExpr();
			if ($expr instanceof FuncCall) {
				if (
					!$expr->name instanceof Name
					// interface_exists() etc. imply class_exists() therefore not listed here
					|| !in_array($expr->name->name, ['class_exists', 'function_exists'], true)
				) {
					continue;
				}
			} elseif ($expr instanceof PropertyFetch) {
				if (!$rememberPropertyState || !$this->isReadonlyPropertyFetch($expr, true)) {
					continue;
				}
			} elseif ($expr instanceof PropertyInitializationExpr) {
				if (!$rememberPropertyState) {
					continue;
				}
			} elseif (!$expr instanceof ConstFetch) {
				continue;
			}

			$expressionTypes[$exprString] = $expressionTypeHolder;
		}

		if (array_key_exists('$this', $currentExpressionTypes)) {
			$expressionTypes['$this'] = $currentExpressionTypes['$this'];
		}

		return $expressionTypes;
	}

	/**
	 * A class with custom serialization logic can be rebuilt by unserialize()
	 * without the constructor ever running, and the author decides which properties
	 * make the round trip - so nothing the constructor established can be relied upon
	 * in the other methods.
	 */
	private function classHasCustomSerialization(): bool
	{
		if (!$this->isInClass()) {
			return false;
		}

		$classReflection = $this->getClassReflection();
		foreach (self::CUSTOM_SERIALIZATION_METHODS as $methodName) {
			if ($classReflection->hasNativeMethod($methodName)) {
				return true;
			}
		}

		return $classReflection->implementsInterface(Serializable::class)
			&& $classReflection->hasNativeMethod('unserialize');
	}

	public function rememberConstructorScope(): self
	{
		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			null,
			$this->getNamespace(),
			$this->rememberConstructorExpressions($this->expressionTypes),
			$this->rememberConstructorExpressions($this->nativeExpressionTypes),
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			[],
			[],
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/** @internal called by ScopeOps */
	public function isReadonlyPropertyFetch(PropertyFetch $expr, bool $allowOnlyOnThis): bool
	{
		if (!$this->services->phpVersion->supportsReadOnlyProperties()) {
			return false;
		}

		while ($expr instanceof PropertyFetch) {
			if ($expr->var instanceof Variable) {
				if (
					$allowOnlyOnThis
					&& (
						! $expr->name instanceof Node\Identifier
						|| !is_string($expr->var->name)
						|| $expr->var->name !== 'this'
					)
				) {
					return false;
				}
			} elseif (!$expr->var instanceof PropertyFetch) {
				return false;
			}

			$propertyReflection = $this->services->propertyReflectionFinder->findPropertyReflectionFromNode($expr, $this);
			if ($propertyReflection === null) {
				return false;
			}

			$nativePropertyReflection = $propertyReflection->getNativeReflection();
			if ($nativePropertyReflection === null || !$nativePropertyReflection->isReadOnly()) {
				return false;
			}

			$expr = $expr->var;
		}

		return true;
	}

	/** @api */
	public function isInClass(): bool
	{
		return $this->context->getClassReflection() !== null;
	}

	/** @api */
	public function isInTrait(): bool
	{
		return $this->context->getTraitReflection() !== null;
	}

	/** @api */
	public function getClassReflection(): ?ClassReflection
	{
		return $this->context->getClassReflection();
	}

	/** @api */
	public function getTraitReflection(): ?ClassReflection
	{
		return $this->context->getTraitReflection();
	}

	/**
	 * @api
	 */
	public function getFunction(): ?PhpFunctionFromParserNodeReflection
	{
		return $this->function;
	}

	/** @api */
	public function getFunctionName(): ?string
	{
		return $this->function !== null ? $this->function->getName() : null;
	}

	/** @api */
	public function getNamespace(): ?string
	{
		return $this->namespace;
	}

	/** @api */
	public function getParentScope(): ?self
	{
		return $this->parentScope;
	}

	/** @api */
	public function canAnyVariableExist(): bool
	{
		return ($this->function === null && !$this->isInAnonymousFunction()) || $this->afterExtractCall;
	}

	public function afterExtractCall(): self
	{
		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			[],
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			true,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	public function afterClearstatcacheCall(): self
	{
		$changed = false;

		$expressionTypes = $this->expressionTypes;
		$nativeExpressionTypes = $this->nativeExpressionTypes;
		foreach (array_keys($expressionTypes) as $exprString) {
			// list from https://www.php.net/manual/en/function.clearstatcache.php

			// stat(), lstat(), file_exists(), is_writable(), is_readable(), is_executable(), is_file(), is_dir(), is_link(), filectime(), fileatime(), filemtime(), fileinode(), filegroup(), fileowner(), filesize(), filetype(), and fileperms().
			foreach ([
				'stat',
				'lstat',
				'file_exists',
				'is_writable',
				'is_writeable',
				'is_readable',
				'is_executable',
				'is_file',
				'is_dir',
				'is_link',
				'filectime',
				'fileatime',
				'filemtime',
				'fileinode',
				'filegroup',
				'fileowner',
				'filesize',
				'filetype',
				'fileperms',
			] as $functionName) {
				if (!str_starts_with($exprString, $functionName . '(') && !str_starts_with($exprString, '\\' . $functionName . '(')) {
					continue;
				}

				unset($expressionTypes[$exprString]);
				unset($nativeExpressionTypes[$exprString]);
				$changed = true;
				continue 2;
			}
		}

		if (!$changed) {
			return $this;
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	public function afterOpenSslCall(string $openSslFunctionName): self
	{
		$expressionTypes = $this->expressionTypes;
		$nativeExpressionTypes = $this->nativeExpressionTypes;

		$errorStringFunction = '\openssl_error_string()';
		if (
			!array_key_exists($errorStringFunction, $expressionTypes)
			&& !array_key_exists($errorStringFunction, $nativeExpressionTypes)
		) {
			return $this;
		}

		$changed = false;
		if (in_array($openSslFunctionName, [
			'openssl_cipher_iv_length',
			'openssl_cms_decrypt',
			'openssl_cms_encrypt',
			'openssl_cms_read',
			'openssl_cms_sign',
			'openssl_cms_verify',
			'openssl_csr_export_to_file',
			'openssl_csr_export',
			'openssl_csr_get_public_key',
			'openssl_csr_get_subject',
			'openssl_csr_new',
			'openssl_csr_sign',
			'openssl_decrypt',
			'openssl_dh_compute_key',
			'openssl_digest',
			'openssl_encrypt',
			'openssl_get_curve_names',
			'openssl_get_privatekey',
			'openssl_get_publickey',
			'openssl_open',
			'openssl_pbkdf2',
			'openssl_pkcs12_export_to_file',
			'openssl_pkcs12_export',
			'openssl_pkcs12_read',
			'openssl_pkcs7_decrypt',
			'openssl_pkcs7_encrypt',
			'openssl_pkcs7_read',
			'openssl_pkcs7_sign',
			'openssl_pkcs7_verify',
			'openssl_pkey_derive',
			'openssl_pkey_export_to_file',
			'openssl_pkey_export',
			'openssl_pkey_get_private',
			'openssl_pkey_get_public',
			'openssl_pkey_new',
			'openssl_private_decrypt',
			'openssl_private_encrypt',
			'openssl_public_decrypt',
			'openssl_public_encrypt',
			'openssl_random_pseudo_bytes',
			'openssl_seal',
			'openssl_sign',
			'openssl_spki_export_challenge',
			'openssl_spki_export',
			'openssl_spki_new',
			'openssl_spki_verify',
			'openssl_verify',
			'openssl_x509_checkpurpose',
			'openssl_x509_export_to_file',
			'openssl_x509_export',
			'openssl_x509_fingerprint',
			'openssl_x509_read',
			'openssl_x509_verify',
		], true)) {
			unset($expressionTypes[$errorStringFunction]);
			unset($nativeExpressionTypes[$errorStringFunction]);
			$changed = true;
		}

		if (!$changed) {
			return $this;
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * Forgets every tracked volatile global-state expression: argument-less
	 * function-call expressions whose value reflects mutable global/output-buffer
	 * state rather than just their arguments, superglobal variables and their offsets
	 * and negative results of existence checks (function_exists(), class_exists(), ...)
	 * because the invalidating code may define the missing function/class/etc.
	 */
	public function invalidateVolatileExpressions(): self
	{
		$expressionTypes = $this->expressionTypes;
		$nativeExpressionTypes = $this->nativeExpressionTypes;

		$changed = VolatileExpressionHelper::invalidateVolatileFunctionCalls($expressionTypes, $nativeExpressionTypes);
		$changed = VolatileExpressionHelper::invalidateSuperglobals($expressionTypes, $nativeExpressionTypes) || $changed;
		$changed = VolatileExpressionHelper::invalidateNegativeExistenceChecks($this, $expressionTypes, $nativeExpressionTypes) || $changed;

		if (!$changed) {
			return $this;
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * Forgets negative results of the given existence checks (function_exists(),
	 * class_exists(), ...) because declaring a symbol may define the previously-missing one.
	 *
	 * @param list<'class_exists'|'interface_exists'|'trait_exists'|'enum_exists'|'function_exists'> $functionNames existence-check function names to forget
	 */
	public function invalidateExistenceCheckExpressions(array $functionNames, ?string $declaredSymbolName): self
	{
		$expressionTypes = $this->expressionTypes;
		$nativeExpressionTypes = $this->nativeExpressionTypes;

		if (!VolatileExpressionHelper::invalidateNegativeExistenceChecks($this, $expressionTypes, $nativeExpressionTypes, $functionNames, $declaredSymbolName)) {
			return $this;
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/** @api */
	public function hasVariableType(string $variableName): TrinaryLogic
	{
		return ScopeOps::hasVariableType($this, $variableName);
	}

	/** @api */
	public function getVariableType(string $variableName): Type
	{
		$hasVariableType = $this->hasVariableType($variableName);

		if ($hasVariableType->maybe()) {
			if ($variableName === 'argc') {
				return StaticTypeFactory::argc();
			}
			if ($variableName === 'argv') {
				return StaticTypeFactory::argv();
			}
			if ($this->canAnyVariableExist()) {
				return new MixedType();
			}
		}

		if ($hasVariableType->no()) {
			throw new UndefinedVariableException($this, $variableName);
		}

		$varExprString = '$' . $variableName;
		if (!array_key_exists($varExprString, $this->expressionTypes)) {
			if ($this->isGlobalVariable($variableName)) {
				return new ArrayType(new BenevolentUnionType([new IntegerType(), new StringType()]), new MixedType(true));
			}
			return new MixedType();
		}

		return $this->expressionTypes[$varExprString]->getType();
	}

	/**
	 * @api
	 * @return list<string>
	 */
	public function getDefinedVariables(): array
	{
		$variables = [];
		foreach ($this->expressionTypes as $exprString => $holder) {
			if (!$holder->getExpr() instanceof Variable) {
				continue;
			}
			if (!$holder->getCertainty()->yes()) {
				continue;
			}

			$variables[] = substr($exprString, 1);
		}

		return $variables;
	}

	/**
	 * @api
	 * @return list<string>
	 */
	public function getMaybeDefinedVariables(): array
	{
		$variables = [];
		foreach ($this->expressionTypes as $exprString => $holder) {
			if (!$holder->getExpr() instanceof Variable) {
				continue;
			}
			if (!$holder->getCertainty()->maybe()) {
				continue;
			}

			$variables[] = substr($exprString, 1);
		}

		return $variables;
	}

	private function isGlobalVariable(string $variableName): bool
	{
		return in_array($variableName, self::SUPERGLOBAL_VARIABLES, true);
	}

	/** @api */
	public function hasConstant(Name $name): bool
	{
		$isCompilerHaltOffset = $name->toString() === '__COMPILER_HALT_OFFSET__';
		if ($isCompilerHaltOffset) {
			return $this->fileHasCompilerHaltStatementCalls();
		}

		if ($this->getGlobalConstantType($name) !== null) {
			return true;
		}

		return $this->services->reflectionProvider->hasConstant($name, $this);
	}

	private function fileHasCompilerHaltStatementCalls(): bool
	{
		$nodes = $this->services->parser->parseFile($this->getFile());
		foreach ($nodes as $node) {
			if ($node instanceof Node\Stmt\HaltCompiler) {
				return true;
			}
		}

		return false;
	}

	/** @api */
	public function isInAnonymousFunction(): bool
	{
		return $this->anonymousFunctionReflection !== null;
	}

	/** @api */
	public function getAnonymousFunctionReflection(): ?ClosureType
	{
		return $this->anonymousFunctionReflection;
	}

	/** @api */
	public function getAnonymousFunctionReturnType(): ?Type
	{
		if ($this->anonymousFunctionReflection === null) {
			return null;
		}

		return $this->anonymousFunctionReflection->getReturnType();
	}

	/**
	 * Returns a scope identical to this one but with the anonymous function
	 * reflection replaced. The scope entered at a closure/arrow carries only a
	 * shallow reflection (parameters + declared return); once the single body
	 * walk has gathered the returns, the engine builds the refined ClosureType and
	 * swaps it in here so the closure/arrow return-type node and its rules see the
	 * refined expected return.
	 */
	public function withAnonymousFunctionReflection(ClosureType $anonymousFunctionReflection): self
	{
		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/** @api */
	public function getType(Expr $node): Type
	{
		// a variable read is scope state and a literal is a constant - neither
		// needs the node walked, so asking about them ahead of the walk is not
		// the on-demand pricing the guard exists to catch
		if (
			NodeScopeResolver::$guardNewWorld
			&& isset(NodeScopeResolver::$guardRealExprIds[spl_object_id($node)])
			&& !isset(NodeScopeResolver::$guardProcessedExprIds[spl_object_id($node)])
			&& !($node instanceof Variable && is_string($node->name))
			&& !$node instanceof Node\Scalar\String_
			&& !$node instanceof Node\Scalar\Int_
			&& !$node instanceof Node\Scalar\Float_
		) {
			throw new ShouldNotHappenException(sprintf(
				'getType() asked about non-synthetic %s on line %d before it was processed by processExprNode() - it should consume the node\'s ExpressionResult instead.',
				get_class($node),
				$node->getStartLine(),
			));
		}

		$type = ScopeOps::getTypeFromCache($this, $node, $key);
		if ($type !== null) {
			return $type;
		}

		return $this->resolvedTypes[$key] = TypeUtils::resolveLateResolvableTypes($this->resolveType($key, $node));
	}

	public function getScopeType(Expr $expr): Type
	{
		return $this->getType($expr);
	}

	public function getScopeNativeType(Expr $expr): Type
	{
		return $this->getNativeType($expr);
	}

	public function getNodeKey(Expr $node): string
	{
		return ScopeOps::nodeKey($node, $this->services->exprPrinter);
	}

	/** @internal */
	public function getExprPrinter(): ExprPrinter
	{
		return $this->services->exprPrinter;
	}

	/**
	 * Creates a copy of this scope with the given expression tables and flags
	 * replaced, keeping context, function, namespace and everything else.
	 *
	 * @internal called by ScopeOps
	 * @param array<string, ExpressionTypeHolder> $expressionTypes
	 * @param array<string, ExpressionTypeHolder> $nativeExpressionTypes
	 * @param array<string, ConditionalExpressionHolder[]> $conditionalExpressions
	 * @param array<string, bool> $currentlyAssignedExpressions
	 * @param array<string, true> $currentlyAllowedUndefinedExpressions
	 * @param list<array{FunctionReflection|MethodReflection|null, ParameterReflection|null}> $inFunctionCallsStack
	 */
	public function duplicateWith(
		array $expressionTypes,
		array $nativeExpressionTypes,
		array $conditionalExpressions,
		array $currentlyAssignedExpressions,
		array $currentlyAllowedUndefinedExpressions,
		array $inFunctionCallsStack,
		bool $inFirstLevelStatement,
		bool $afterExtractCall,
	): self
	{
		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$inFirstLevelStatement,
			$currentlyAssignedExpressions,
			$currentlyAllowedUndefinedExpressions,
			$inFunctionCallsStack,
			$afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * A cache key of the scope state a closure's type can depend on. With
	 * $relevantRoots (the closure's free variables, '$this' included) only
	 * the expression types rooted in them contribute - narrow enough that
	 * loop-local churn does not invalidate the closure's cached type. Null
	 * means everything contributes (dynamic variable access in the body).
	 *
	 * @param list<string>|null $relevantRoots
	 */
	public function getClosureScopeCacheKey(?array $relevantRoots = null): string
	{
		$parts = [];
		foreach ($this->expressionTypes as $exprString => $expressionTypeHolder) {
			if ($expressionTypeHolder->getExpr() instanceof VirtualNode) {
				continue;
			}
			if ($relevantRoots !== null && !self::exprStringIsRootedIn($exprString, $relevantRoots)) {
				continue;
			}
			$parts[] = sprintf('%s::%s', $exprString, $expressionTypeHolder->getType()->describe(VerbosityLevel::cache()));
		}
		$parts[] = '---';

		$parts[] = sprintf(':%d', count($this->inFunctionCallsStack));
		foreach ($this->inFunctionCallsStack as [, $parameter]) {
			if ($parameter === null) {
				$parts[] = ',null';
				continue;
			}

			$parts[] = sprintf(',%s', $parameter->getType()->describe(VerbosityLevel::cache()));
		}

		return md5(implode("\n", $parts));
	}

	/** @param list<string> $roots */
	private static function exprStringIsRootedIn(string $exprString, array $roots): bool
	{
		foreach ($roots as $root) {
			if ($exprString === $root) {
				return true;
			}
			if (!str_starts_with($exprString, $root)) {
				continue;
			}

			$next = $exprString[strlen($root)];
			if ($next !== '_' && !ctype_alnum($next)) {
				return true;
			}
		}

		return false;
	}

	private function resolveType(string $exprString, Expr $node): Type
	{
		foreach ($this->services->expressionTypeResolverExtensions->getAll() as $extension) {
			$type = $extension->getType($node, $this);
			if ($type !== null) {
				return $type;
			}
		}

		$expressionType = ScopeOps::expressionTypeByKey($this, $node, $exprString);
		if ($expressionType !== null) {
			return $expressionType;
		}

		// NodeScopeResolver intercepts a first-class callable CallLike before the
		// ExprHandler dispatch - no handler supports the original node, its closure
		// type lives on the stored result's typeCallback (see the *CallableNode
		// handlers), mirroring TypeSpecifier::specifyTypesInCondition().
		if ($node instanceof Expr\CallLike && $node->isFirstClassCallable()) {
			return $this->resolveTypeOfNewWorldHandlerNode($node);
		}

		$exprHandler = ExprHandlerRegistry::resolve($node, $this->services->container);
		if ($exprHandler !== null) {
			return $this->resolveTypeOfNewWorldHandlerNode($node);
		}

		return new MixedType();
	}

	/**
	 * Resolves the type of a node whose ExprHandler produced an ExpressionResult.
	 * The answer comes from the ExpressionResult stored during the analysis
	 * currently in progress (its eager type or typeCallback), or from processing
	 * the node on demand (synthetic nodes, or no analysis in progress at all).
	 *
	 * The scope deliberately does not reference the storage - that would create
	 * a reference cycle that never gets collected (see ExpressionResultStorageStack).
	 */
	private function resolveTypeOfNewWorldHandlerNode(Expr $node): Type
	{
		// the hooks are the boundary between the rule-facing world and the
		// engine - a rule's NodeCallbackScope must not flow into result
		// callbacks or on-demand processing
		$scope = $this->toWalkScope();
		$storage = $this->services->expressionResultStorageStack->getCurrent();
		$counterfactualAsk = false;
		if ($storage !== null) {
			$result = $storage->findExpressionResult($node);
			if ($result !== null && $result->canResolveOwnType()) {
				// a counterfactual ask (the asking scope re-binds a variable the
				// expression reads, e.g. array_filter pricing its callback body
				// per constant element) must re-price the node on that scope -
				// the memoized walk-position type answers a different question
				$counterfactualAsk = !$result->askScopeVariableStateMatches($scope, $scope->nativeTypesPromoted);
				if (!$counterfactualAsk) {
					return $result->getTypeOnScope($scope, $scope->nativeTypesPromoted);
				}
			}
		}

		// A closure/arrow function type is computed directly (as
		// resolveCallableTypeForScope() also does) - never by processing it on
		// demand, which would re-enter ClosureHandler::processExpr() endlessly.
		// This answers both a closure whose result is not stored yet (its own
		// body walk asks for its type, and a callable parameter is derived from
		// it while it is being processed) and a closure passed as a call argument,
		// whose result NodeScopeResolver stores without an eager type.
		// getClosureType()'s own depth guard answers the self-by-ref ask.
		if ($node instanceof Expr\Closure || $node instanceof Expr\ArrowFunction) {
			return $this->services->container->getByType(ClosureTypeResolver::class)->getClosureType($scope, $node, false, $storage);
		}

		if (!$counterfactualAsk && $storage !== null && $storage->findExpressionResult($node) !== null) {
			throw new ShouldNotHappenException(sprintf(
				'ExpressionResult of %s cannot resolve its own type (no eager type, no typeCallback).',
				get_class($node),
			));
		}

		// a synthetic node, or no analysis in progress
		$onDemandResult = $this->services->container->getByType(NodeScopeResolver::class)->processExprOnDemand(
			$node,
			$scope,
			$storage !== null ? $storage->duplicate() : new ExpressionResultStorage(),
		);

		return $onDemandResult->getTypeOnScope($scope, $scope->nativeTypesPromoted);
	}

	/**
	 * Prices the current (phpdoc, native) type pair of an expression that
	 * applySpecifiedTypes() needs to intersect with or subtract from but that
	 * is not tracked in the scope. Old-world filterBySpecifiedTypes() asked
	 * Scope::getType() here; pricing from the stored ExpressionResult answers
	 * through the typeCallback for converted handlers. A synthetic node the
	 * analysis never processed - e.g. the plain-chain variant a nullsafe
	 * narrowing emits ($a->b() alongside $a?->b()) - is priced on demand,
	 * mirroring resolveTypeOfNewWorldHandlerNode(); its real subnodes answer
	 * from stored results so the on-demand walk terminates. Returns null only
	 * when there is no analysis in progress to price against.
	 *
	 * @return array{Type, Type}|null
	 */
	private function getCurrentTypesOfSpecifiedExpr(Expr $expr): ?array
	{
		$storage = $this->services->expressionResultStorageStack->getCurrent();
		if ($storage === null) {
			return null;
		}

		// a narrowable expression's scope-view type is derived from tracked
		// state - the application-point semantics this method exists for. The
		// stored result must NOT win here: a narrowing entry's node sits inside
		// the condition (the \$a of `'' !== \$a`, walked on a truthy branch), so
		// its walk-position type carries branch narrowing that would poison the
		// base the narrowing is applied to. A nullsafe-containing chain is the
		// exception: deriving it from tracked state re-prices its links on
		// receiver state an active isset/?? ensure devices non-null, losing the
		// short-circuit's null - its stored result keeps it.
		$exprResult = $storage->findExpressionResult($expr);
		if (
			(
				($expr instanceof Expr\Variable && is_string($expr->name))
				|| $expr instanceof PropertyFetch
				|| $expr instanceof Expr\ArrayDimFetch
				|| $expr instanceof Expr\StaticPropertyFetch
				// argument-less instance calls: the shape @phpstan-assert subjects
				// take (synthetic per-build nodes, never stored - a walk per
				// application otherwise)
				|| ($expr instanceof Expr\MethodCall && $expr->name instanceof Identifier && !$expr->isFirstClassCallable() && $expr->getArgs() === [])
			)
			&& ($exprResult === null || !$exprResult->containsNullsafe())
		) {
			return [
				$this->resolveScopeStateType($expr, $this->nativeTypesPromoted),
				$this->resolveScopeStateType($expr, true),
			];
		}

		$result = $exprResult;
		if ($result === null) {
			// a call subject (or a synthetic plain-chain variant) is priced on
			// demand: one walk answers both flavours. Not memoized - a census
			// showed repeat asks for the same unstored subject on one scope
			// never happen (0 hits across corpora)
			$scope = $this->toWalkScope();
			$result = $this->services->container->getByType(NodeScopeResolver::class)->processExprOnDemand(
				$expr,
				$scope,
				$storage->duplicate(),
			);

			return [
				$result->getTypeOnScope($scope, $scope->nativeTypesPromoted),
				$result->getTypeOnScope($scope, true),
			];
		}

		// a type tracked for the whole expression on the asking scope wins over
		// the stored result's own type: a handler (e.g. isset/empty via
		// NonNullabilityHelper) may have processed the inner expression on a
		// scope that strips null, so the result's type would be stale for the
		// narrowing the caller is applying
		return [
			$result->getTypeOnScope($this, $this->nativeTypesPromoted),
			$result->getTypeOnScope($this, true),
		];
	}

	/**
	 * Narrowing counterpart of resolveTypeOfNewWorldHandlerNode() - the old-world
	 * TypeSpecifier dispatcher asks here for a node's narrowing. Returns null when
	 * the ExpressionResult carries no specifyTypesCallback - the dispatcher falls
	 * back to default truthy/falsey narrowing.
	 *
	 * @internal
	 */
	public function specifyTypesOfNewWorldHandlerNode(Expr $node, TypeSpecifierContext $context): SpecifiedTypes
	{
		return $this->obtainResultForNode($node)->getSpecifiedTypesForScope($this->toWalkScope(), $context);
	}

	/**
	 * Obtains the ExpressionResult of a node so its narrowing/type can be asked
	 * (getSpecifiedTypesForScope()/getTypeOnScope()): the stored result of an
	 * already-processed node, or - for a synthetic node (or with no analysis in
	 * progress) - the result of processing it on demand against a duplicate of
	 * the current storage, so the throwaway walk never pollutes the live one.
	 */
	public function obtainResultForNode(Expr $node): ExpressionResult
	{
		$storage = $this->services->expressionResultStorageStack->getCurrent();
		if ($storage !== null) {
			$result = $storage->findExpressionResult($node);
			if ($result !== null) {
				return $result;
			}
		}

		if (
			NodeScopeResolver::$guardNewWorld
			&& isset(NodeScopeResolver::$guardRealExprIds[spl_object_id($node)])
			&& !isset(NodeScopeResolver::$guardProcessedExprIds[spl_object_id($node)])
		) {
			throw new ShouldNotHappenException(sprintf(
				'obtainResultForNode() asked about non-synthetic %s on line %d before it was processed by processExprNode() - it should consume the node\'s ExpressionResult instead.',
				get_class($node),
				$node->getStartLine(),
			));
		}

		// see resolveTypeOfNewWorldHandlerNode() - rules ask the dispatcher
		// with their NodeCallbackScope (e.g. ImpossibleCheckTypeHelper), the engine
		// side of the boundary works with the mutating flavor
		$scope = $this->toWalkScope();

		// a synthetic node, or no analysis in progress
		return $this->services->container->getByType(NodeScopeResolver::class)->processExprOnDemand(
			$node,
			$scope,
			$storage !== null ? $storage->duplicate() : new ExpressionResultStorage(),
		);
	}

	/**
	 * Makes the storage answer type questions asked on this scope (and every
	 * scope sharing its ExpressionResultStorageStack) for the duration of an
	 * analysis. The caller must pop in a finally block.
	 */
	public function pushExpressionResultStorage(ExpressionResultStorage $storage): void
	{
		$this->services->expressionResultStorageStack->push($storage);
	}

	public function popExpressionResultStorage(): void
	{
		$this->services->expressionResultStorageStack->pop();
	}

	/**
	 * The ExpressionResultStorage of the analysis currently in progress, the one
	 * resolveTypeOfNewWorldHandlerNode() prices synthetic nodes against. A handler
	 * pricing a synthetic node from a lazily-invoked typeCallback must use this
	 * (not a storage captured at processExpr() time): a later re-evaluation
	 * (e.g. findEarlyTerminatingExpr()) runs under a different current storage,
	 * and the captured one would resolve the synthetic node's real subnodes from
	 * stale stored results.
	 *
	 * @internal
	 */
	/** The settled stored result of the current storage - NodeCallbackScope's no-switch fast path. */
	protected function findSettledStoredResult(Expr $node): ?ExpressionResult
	{
		$storage = $this->services->expressionResultStorageStack->getCurrent();
		if ($storage === null) {
			return null;
		}

		return $storage->findExpressionResult($node);
	}

	public function getCurrentExpressionResultStorage(): ?ExpressionResultStorage
	{
		return $this->services->expressionResultStorageStack->getCurrent();
	}

	public function withTemplateArgumentFrame(?TemplateArgumentFrame $frame): self
	{
		$scope = $this->withoutMemoizedTypes();
		$scope->templateArgumentFrame = $frame;
		return $scope;
	}

	public function getCurrentTemplateArgumentFrame(): ?TemplateArgumentFrame
	{
		return $this->templateArgumentFrame;
	}

	public function getTemplateArgumentConstraints(): ?TemplateArgumentConstraints
	{
		return $this->templateArgumentConstraints;
	}

	public function withTemplateArgumentConstraints(?TemplateArgumentConstraints $constraints): self
	{
		if ($constraints === $this->templateArgumentConstraints) {
			return $this;
		}
		$scope = clone $this;
		$scope->nodeCallbackScope = null;
		$scope->scopeOutOfFirstLevelStatement = null;
		$scope->scopeWithPromotedNativeTypes = null;
		$scope->templateArgumentConstraints = $constraints;
		return $scope;
	}

	/** Inference facts join independently of variable-state convergence and branch termination. */
	public function addTemplateArgumentConstraints(?TemplateArgumentConstraints $constraints): self
	{
		if ($constraints === null || $constraints->isEmpty()) {
			return $this;
		}

		return $this->withTemplateArgumentConstraints($this->templateArgumentConstraints === null ? $constraints : $this->templateArgumentConstraints->merge($constraints));
	}

	/**
	 * A copy of this scope without its memoized type answers: the recorded
	 * entry scope of a statement the second pass re-walks answered questions
	 * during the observation pass with unresolved template arguments in them.
	 */
	public function withoutMemoizedTypes(): self
	{
		return $this->duplicateWith(
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->inFirstLevelStatement,
			$this->afterExtractCall,
		);
	}

	/**
	 * The variables spelled by the tracked expressions whose state differs
	 * between this scope and $other - a statement mentioning none of them walks
	 * the same on both - or null when a differing entry has no variable root (a
	 * static property, a class constant fetch). Every variable of an entry counts,
	 * not just its root: assigning $b invalidates $a->get($b).
	 *
	 * @return list<string>|null
	 */
	public function getDifferingVariableRoots(self $other): ?array
	{
		$roots = [];
		$tables = [
			[$this->expressionTypes, $other->expressionTypes],
			[$this->nativeExpressionTypes, $other->nativeExpressionTypes],
		];
		foreach ($tables as [$ours, $theirs]) {
			foreach ($ours as $key => $holder) {
				$theirHolder = $theirs[$key] ?? null;
				if ($theirHolder !== null && ($theirHolder === $holder || $holder->equals($theirHolder))) {
					continue;
				}
				$variables = self::getVariablesOfExpressionKey($key);
				if ($variables === null) {
					return null;
				}
				foreach ($variables as $variable) {
					$roots[$variable] = true;
				}
			}
			foreach ($theirs as $key => $holder) {
				if (isset($ours[$key])) {
					continue;
				}
				$variables = self::getVariablesOfExpressionKey($key);
				if ($variables === null) {
					return null;
				}
				foreach ($variables as $variable) {
					$roots[$variable] = true;
				}
			}
		}
		$conditionalTables = [
			[$this->conditionalExpressions, $other->conditionalExpressions],
			[$other->conditionalExpressions, $this->conditionalExpressions],
		];
		foreach ($conditionalTables as [$ours, $theirs]) {
			foreach ($ours as $key => $holders) {
				if (isset($theirs[$key]) && $theirs[$key] === $holders) {
					continue;
				}
				$variables = self::getVariablesOfExpressionKey($key);
				if ($variables === null) {
					return null;
				}
				foreach ($variables as $variable) {
					$roots[$variable] = true;
				}
			}
		}

		return array_keys($roots);
	}

	/**
	 * The variables an expression key spells, or null when the key is not
	 * rooted in a variable.
	 *
	 * @return list<string>|null
	 */
	private static function getVariablesOfExpressionKey(string $key): ?array
	{
		if (preg_match('/^\$[a-zA-Z_\x80-\xff]/', $key) !== 1) {
			return null;
		}

		preg_match_all('/\$([a-zA-Z_\x80-\xff][a-zA-Z0-9_\x80-\xff]*)/', $key, $matches);

		return $matches[1];
	}

	/**
	 * This scope after a statement whose recorded walk stands: the entries the
	 * statement changed or removed between its recorded entry and exit scopes
	 * are carried over, everything else keeps this scope's state.
	 */
	public function withRecordedStatementDelta(self $recordedEntry, self $recordedExit): self
	{
		$conditionalExpressions = $this->conditionalExpressions;
		foreach ($recordedExit->conditionalExpressions as $key => $holders) {
			if (isset($recordedEntry->conditionalExpressions[$key]) && $recordedEntry->conditionalExpressions[$key] === $holders) {
				continue;
			}
			$conditionalExpressions[$key] = $holders;
		}
		foreach (array_keys($recordedEntry->conditionalExpressions) as $key) {
			if (isset($recordedExit->conditionalExpressions[$key])) {
				continue;
			}
			unset($conditionalExpressions[$key]);
		}

		return $this->duplicateWith(
			self::applyRecordedHolderDelta($this->expressionTypes, $recordedEntry->expressionTypes, $recordedExit->expressionTypes),
			self::applyRecordedHolderDelta($this->nativeExpressionTypes, $recordedEntry->nativeExpressionTypes, $recordedExit->nativeExpressionTypes),
			$conditionalExpressions,
			[],
			[],
			[],
			$this->inFirstLevelStatement,
			$recordedExit->afterExtractCall,
		);
	}

	/**
	 * @param array<string, ExpressionTypeHolder> $current
	 * @param array<string, ExpressionTypeHolder> $recordedEntry
	 * @param array<string, ExpressionTypeHolder> $recordedExit
	 * @return array<string, ExpressionTypeHolder>
	 */
	private static function applyRecordedHolderDelta(array $current, array $recordedEntry, array $recordedExit): array
	{
		foreach ($recordedExit as $key => $holder) {
			$entryHolder = $recordedEntry[$key] ?? null;
			if ($entryHolder !== null && ($entryHolder === $holder || $entryHolder->equals($holder))) {
				continue;
			}
			$current[$key] = $holder;
		}
		foreach (array_keys($recordedEntry) as $key) {
			if (isset($recordedExit[$key])) {
				continue;
			}
			unset($current[$key]);
		}

		return $current;
	}

	/** @api */
	public function getNativeType(Expr $expr): Type
	{
		return $this->promoteNativeTypes()->getType($expr);
	}

	public function getKeepVoidType(Expr $node): Type
	{
		if (
			!$node instanceof Match_
			&& !$node instanceof Expr\Yield_
			&& !$node instanceof Expr\YieldFrom
			&& (
				(
					!$node instanceof FuncCall
					&& !$node instanceof MethodCall
					&& !$node instanceof Expr\NullsafeMethodCall
					&& !$node instanceof Expr\StaticCall
				) || $node->isFirstClassCallable()
			)
		) {
			return $this->getScopeStateType($node);
		}

		$originalType = $this->getScopeStateType($node);
		if (!TypeCombinator::containsNull($originalType)) {
			return $originalType;
		}

		// the null may be a projected void: read the call's/match's raw
		// (void-kept) own type. A result already stored in the current frame is
		// read directly; a node evaluated on a different scope - e.g. an arrow
		// body typed on the closure scope - is processed on demand there, its
		// raw own type keeping void without any keep-void marker on the node.
		$storage = $this->services->expressionResultStorageStack->getCurrent();
		$result = $storage !== null ? $storage->findExpressionResult($node) : null;
		if ($result === null) {
			$result = $this->services->container->getByType(NodeScopeResolver::class)->processExprOnDemand(
				$node,
				$this->toWalkScope(),
				$storage !== null ? $storage->duplicate() : new ExpressionResultStorage(),
			);
		}

		return $result->getKeepVoidType($this->nativeTypesPromoted);
	}

	public function doNotTreatPhpDocTypesAsCertain(): self
	{
		return $this->promoteNativeTypes();
	}

	private function promoteNativeTypes(): self
	{
		if ($this->nativeTypesPromoted) {
			return $this;
		}

		if ($this->scopeWithPromotedNativeTypes !== null) {
			return $this->scopeWithPromotedNativeTypes;
		}

		return $this->scopeWithPromotedNativeTypes = $this->scopeFactory->create(
			$this->context,
			$this->declareStrictTypes,
			$this->function,
			$this->namespace,
			$this->nativeExpressionTypes,
			[],
			[],
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			true,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	/** @api */
	public function resolveName(Name $name): string
	{
		$originalClass = (string) $name;
		if ($this->isInClass()) {
			$lowerClass = strtolower($originalClass);
			if (in_array($lowerClass, [
				'self',
				'static',
			], true)) {
				if ($this->inClosureBindScopeClasses !== [] && $this->inClosureBindScopeClasses !== ['static']) {
					return $this->inClosureBindScopeClasses[0];
				}
				return $this->getClassReflection()->getName();
			} elseif ($lowerClass === 'parent') {
				$currentClassReflection = $this->getClassReflection();
				if ($currentClassReflection->getParentClass() !== null) {
					return $currentClassReflection->getParentClass()->getName();
				}
			}
		}

		return $originalClass;
	}

	/** @api */
	public function resolveTypeByName(Name $name): TypeWithClassName
	{
		if ($name->toLowerString() === 'static' && $this->isInClass()) {
			if ($this->inClosureBindScopeClasses !== [] && $this->inClosureBindScopeClasses !== ['static']) {
				if ($this->services->reflectionProvider->hasClass($this->inClosureBindScopeClasses[0])) {
					return new StaticType($this->services->reflectionProvider->getClass($this->inClosureBindScopeClasses[0]));
				}
			}

			return new StaticType($this->getClassReflection());
		}

		$originalClass = $this->resolveName($name);
		if ($this->isInClass()) {
			if ($this->inClosureBindScopeClasses === [$originalClass]) {
				if ($this->services->reflectionProvider->hasClass($originalClass)) {
					return new ThisType($this->services->reflectionProvider->getClass($originalClass));
				}
				return new ObjectType($originalClass);
			}

			$thisType = new ThisType($this->getClassReflection());
			$ancestor = $thisType->getAncestorWithClassName($originalClass);
			if ($ancestor !== null) {
				return $ancestor;
			}
		}

		return new ObjectType($originalClass);
	}

	/**
	 * @api
	 * @param mixed $value
	 */
	public function getTypeFromValue($value): Type
	{
		return ConstantTypeHelper::getTypeFromValue($value);
	}

	/** @api */
	public function hasExpressionType(Expr $node): TrinaryLogic
	{
		return ScopeOps::hasExpressionType($this, $node, $this->services->exprPrinter);
	}

	/**
	 * Reads the type tracked for an expression straight from its holder, skipping
	 * the extension/dispatch/cache machinery that getType() runs. Only valid when
	 * hasExpressionType($node) is yes - mirrors resolveType()'s tracked-holder
	 * early return and is what ExpressionResult uses on its tracked-holder path.
	 *
	 * @internal
	 */
	public function getTrackedExpressionType(Expr $node): Type
	{
		return $this->expressionTypes[$this->getNodeKey($node)]->getType();
	}

	/**
	 * @param MethodReflection|FunctionReflection|null $reflection
	 */
	public function pushInFunctionCall($reflection, ?ParameterReflection $parameter, bool $rememberTypes): self
	{
		$stack = $this->inFunctionCallsStack;
		$stack[] = [$reflection, $parameter];

		$functionScope = $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$stack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);

		if ($rememberTypes) {
			$functionScope->resolvedTypes = $this->resolvedTypes;
		}

		return $functionScope;
	}

	public function popInFunctionCall(): self
	{
		$stack = $this->inFunctionCallsStack;
		array_pop($stack);

		$parentScope = $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$stack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);

		$parentScope->resolvedTypes = $this->resolvedTypes;

		return $parentScope;
	}

	/** @api */
	public function isInClassExists(string $className): bool
	{
		foreach ($this->inFunctionCallsStack as [$inFunctionCall]) {
			if (!$inFunctionCall instanceof FunctionReflection) {
				continue;
			}

			if (in_array($inFunctionCall->getName(), [
				'class_exists',
				'interface_exists',
				'trait_exists',
				'enum_exists',
			], true)) {
				return true;
			}
		}

		// interface_exists() etc. imply class_exists() therefore not listed here
		$expr = new FuncCall(new FullyQualified('class_exists'), [
			new Arg(new String_(ltrim($className, '\\'))),
		]);

		return $this->getType($expr)->isTrue()->yes();
	}

	public function getFunctionCallStack(): array
	{
		return array_values(array_filter(
			array_map(static fn ($values) => $values[0], $this->inFunctionCallsStack),
			static fn (FunctionReflection|MethodReflection|null $reflection) => $reflection !== null,
		));
	}

	public function getFunctionCallStackWithParameters(): array
	{
		return array_values(array_filter(
			$this->inFunctionCallsStack,
			static fn ($item) => $item[0] !== null,
		));
	}

	/** @api */
	public function isInFunctionExists(string $functionName): bool
	{
		$expr = new FuncCall(new FullyQualified('function_exists'), [
			new Arg(new String_(ltrim($functionName, '\\'))),
		]);

		return $this->getType($expr)->isTrue()->yes();
	}

	/** @api */
	public function enterClass(ClassReflection $classReflection): self
	{
		$thisHolder = ExpressionTypeHolder::createYes(new Variable('this'), new ThisType($classReflection));
		$constantTypes = $this->getConstantTypes();
		$constantTypes['$this'] = $thisHolder;
		$nativeConstantTypes = $this->getNativeConstantTypes();
		$nativeConstantTypes['$this'] = $thisHolder;

		return $this->scopeFactory->create(
			$this->context->enterClass($classReflection),
			$this->isDeclareStrictTypes(),
			null,
			$this->getNamespace(),
			$constantTypes,
			$nativeConstantTypes,
			[],
			[],
			null,
			true,
			[],
			[],
			[],
			false,
			$classReflection->isAnonymous() ? $this : null,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	public function enterTrait(ClassReflection $traitReflection): self
	{
		$namespace = null;
		$traitName = $traitReflection->getName();
		$traitNameParts = explode('\\', $traitName);
		if (count($traitNameParts) > 1) {
			$namespace = implode('\\', array_slice($traitNameParts, 0, -1));
		}
		return $this->scopeFactory->create(
			$this->context->enterTrait($traitReflection),
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$namespace,
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			[],
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	/**
	 * @api
	 * @param Type[] $phpDocParameterTypes
	 * @param Type[] $parameterOutTypes
	 * @param array<string, bool> $immediatelyInvokedCallableParameters
	 * @param array<string, Type> $phpDocClosureThisTypeParameters
	 * @param array<string, bool> $phpDocPureUnlessCallableIsImpureParameters
	 * @param array<string, bool> $phpDocPureUnlessParameterPassedParameters
	 */
	public function enterClassMethod(
		Node\Stmt\ClassMethod $classMethod,
		TemplateTypeMap $templateTypeMap,
		array $phpDocParameterTypes,
		?Type $phpDocReturnType,
		?Type $throwType,
		?string $deprecatedDescription,
		bool $isDeprecated,
		bool $isInternal,
		bool $isFinal,
		?bool $isPure = null,
		bool $acceptsNamedArguments = true,
		?Assertions $asserts = null,
		?Type $selfOutType = null,
		?string $phpDocComment = null,
		array $parameterOutTypes = [],
		array $immediatelyInvokedCallableParameters = [],
		array $phpDocClosureThisTypeParameters = [],
		bool $isConstructor = false,
		?ResolvedPhpDocBlock $resolvedPhpDocBlock = null,
		array $phpDocPureUnlessCallableIsImpureParameters = [],
		array $phpDocPureUnlessParameterPassedParameters = [],
	): self
	{
		if (!$this->isInClass()) {
			throw new ShouldNotHappenException();
		}

		return $this->enterFunctionLike(
			new PhpMethodFromParserNodeReflection(
				$this->getClassReflection(),
				$classMethod,
				null,
				$this->getFile(),
				$templateTypeMap,
				$this->getRealParameterTypes($classMethod),
				array_map(fn (Type $type): Type => $this->transformStaticType(TemplateTypeHelper::toArgument($type)), $phpDocParameterTypes),
				$this->getRealParameterDefaultValues($classMethod),
				$this->getParameterAttributes($classMethod),
				$this->transformStaticType($this->getFunctionType($classMethod->returnType, false, false)),
				$phpDocReturnType !== null ? $this->transformStaticType(TemplateTypeHelper::toArgument($phpDocReturnType)) : null,
				$throwType !== null ? $this->transformStaticType(TemplateTypeHelper::toArgument($throwType)) : null,
				$deprecatedDescription,
				$isDeprecated,
				$isInternal,
				$isFinal,
				$isPure,
				$acceptsNamedArguments,
				$asserts ?? Assertions::createEmpty(),
				$selfOutType,
				$phpDocComment,
				$resolvedPhpDocBlock,
				array_map(fn (Type $type): Type => $this->transformStaticType(TemplateTypeHelper::toArgument($type)), $parameterOutTypes),
				$immediatelyInvokedCallableParameters,
				array_map(fn (Type $type): Type => $this->transformStaticType(TemplateTypeHelper::toArgument($type)), $phpDocClosureThisTypeParameters),
				$isConstructor,
				$this->services->attributeReflectionFactory->fromAttrGroups($classMethod->attrGroups, InitializerExprContext::fromStubParameter($this->getClassReflection()->getName(), $this->getFile(), $classMethod)),
				$phpDocPureUnlessCallableIsImpureParameters,
				$phpDocPureUnlessParameterPassedParameters,
			),
			!$classMethod->isStatic(),
		);
	}

	/**
	 * @param Type[] $phpDocParameterTypes
	 */
	public function enterPropertyHook(
		Node\PropertyHook $hook,
		string $propertyName,
		Identifier|Name|ComplexType|null $nativePropertyTypeNode,
		?Type $phpDocPropertyType,
		array $phpDocParameterTypes,
		?Type $throwType,
		?string $deprecatedDescription,
		bool $isDeprecated,
		?bool $isPure,
		?string $phpDocComment,
		?ResolvedPhpDocBlock $resolvedPhpDocBlock = null,
	): self
	{
		if (!$this->isInClass()) {
			throw new ShouldNotHappenException();
		}

		$phpDocParameterTypes = array_map(fn (Type $type): Type => $this->transformStaticType(TemplateTypeHelper::toArgument($type)), $phpDocParameterTypes);

		$hookName = $hook->name->toLowerString();
		if ($hookName === 'set') {
			if ($hook->params === []) {
				$hook = clone $hook;
				$hook->params = [
					new Node\Param(new Variable('value'), type: $nativePropertyTypeNode),
				];
			}

			$firstParam = $hook->params[0] ?? null;
			if (
				$firstParam !== null
				&& $phpDocPropertyType !== null
				&& $firstParam->var instanceof Variable
				&& is_string($firstParam->var->name)
			) {
				$valueParamPhpDocType = $phpDocParameterTypes[$firstParam->var->name] ?? null;
				if ($valueParamPhpDocType === null) {
					$phpDocParameterTypes[$firstParam->var->name] = $this->transformStaticType(TemplateTypeHelper::toArgument($phpDocPropertyType));
				}
			}

			$realReturnType = new VoidType();
			$phpDocReturnType = null;
		} elseif ($hookName === 'get') {
			$realReturnType = $this->getFunctionType($nativePropertyTypeNode, false, false);
			$phpDocReturnType = $phpDocPropertyType !== null ? $this->transformStaticType(TemplateTypeHelper::toArgument($phpDocPropertyType)) : null;
		} else {
			throw new ShouldNotHappenException();
		}

		$realParameterTypes = $this->getRealParameterTypes($hook);

		return $this->enterFunctionLike(
			new PhpMethodFromParserNodeReflection(
				$this->getClassReflection(),
				$hook,
				$propertyName,
				$this->getFile(),
				TemplateTypeMap::createEmpty(),
				$realParameterTypes,
				$phpDocParameterTypes,
				[],
				$this->getParameterAttributes($hook),
				$realReturnType,
				$phpDocReturnType,
				$throwType !== null ? $this->transformStaticType(TemplateTypeHelper::toArgument($throwType)) : null,
				$deprecatedDescription,
				$isDeprecated,
				false,
				false,
				$isPure,
				true,
				Assertions::createEmpty(),
				null,
				$phpDocComment,
				$resolvedPhpDocBlock,
				[],
				[],
				[],
				false,
				$this->services->attributeReflectionFactory->fromAttrGroups($hook->attrGroups, InitializerExprContext::fromStubParameter($this->getClassReflection()->getName(), $this->getFile(), $hook)),
				[],
				[],
			),
			true,
		);
	}

	private function transformStaticType(Type $type): Type
	{
		return TypeTraverser::mapMemoized($type, new TransformStaticTypeTraverser($this));
	}

	/**
	 * @return Type[]
	 */
	private function getRealParameterTypes(Node\FunctionLike $functionLike): array
	{
		$realParameterTypes = [];
		foreach ($functionLike->getParams() as $parameter) {
			if (!$parameter->var instanceof Variable || !is_string($parameter->var->name)) {
				throw new ShouldNotHappenException();
			}
			$realParameterTypes[$parameter->var->name] = $this->getFunctionType(
				$parameter->type,
				$this->isParameterValueNullable($parameter) && $parameter->flags === 0,
				false,
			);
		}

		return $realParameterTypes;
	}

	/**
	 * @return Type[]
	 */
	private function getRealParameterDefaultValues(Node\FunctionLike $functionLike): array
	{
		$realParameterDefaultValues = [];
		foreach ($functionLike->getParams() as $parameter) {
			if ($parameter->default === null) {
				continue;
			}
			if (!$parameter->var instanceof Variable || !is_string($parameter->var->name)) {
				throw new ShouldNotHappenException();
			}
			$realParameterDefaultValues[$parameter->var->name] = $this->services->initializerExprTypeResolver->getType($parameter->default, InitializerExprContext::fromScope($this));
		}

		return $realParameterDefaultValues;
	}

	/**
	 * @return array<string, list<AttributeReflection>>
	 */
	private function getParameterAttributes(ClassMethod|Function_|PropertyHook $functionLike): array
	{
		$parameterAttributes = [];
		$className = null;
		if ($this->isInClass()) {
			$className = $this->getClassReflection()->getName();
		}
		foreach ($functionLike->getParams() as $parameter) {
			if (!$parameter->var instanceof Variable || !is_string($parameter->var->name)) {
				throw new ShouldNotHappenException();
			}

			$parameterAttributes[$parameter->var->name] = $this->services->attributeReflectionFactory->fromAttrGroups($parameter->attrGroups, InitializerExprContext::fromStubParameter($className, $this->getFile(), $functionLike));
		}

		return $parameterAttributes;
	}

	/**
	 * @api
	 * @param Type[] $phpDocParameterTypes
	 * @param Type[] $parameterOutTypes
	 * @param array<string, bool> $immediatelyInvokedCallableParameters
	 * @param array<string, Type> $phpDocClosureThisTypeParameters
	 * @param array<string, bool> $pureUnlessCallableIsImpureParameters
	 * @param array<string, bool> $pureUnlessParameterPassedParameters
	 */
	public function enterFunction(
		Node\Stmt\Function_ $function,
		TemplateTypeMap $templateTypeMap,
		array $phpDocParameterTypes,
		?Type $phpDocReturnType,
		?Type $throwType,
		?string $deprecatedDescription,
		bool $isDeprecated,
		bool $isInternal,
		?bool $isPure = null,
		bool $acceptsNamedArguments = true,
		?Assertions $asserts = null,
		?string $phpDocComment = null,
		array $parameterOutTypes = [],
		array $immediatelyInvokedCallableParameters = [],
		array $phpDocClosureThisTypeParameters = [],
		array $pureUnlessCallableIsImpureParameters = [],
		array $pureUnlessParameterPassedParameters = [],
	): self
	{
		return $this->enterFunctionLike(
			new PhpFunctionFromParserNodeReflection(
				$function,
				$this->getFile(),
				$templateTypeMap,
				$this->getRealParameterTypes($function),
				array_map(static fn (Type $type): Type => TemplateTypeHelper::toArgument($type), $phpDocParameterTypes),
				$this->getRealParameterDefaultValues($function),
				$this->getParameterAttributes($function),
				$this->getFunctionType($function->returnType, $function->returnType === null, false),
				$phpDocReturnType !== null ? TemplateTypeHelper::toArgument($phpDocReturnType) : null,
				$throwType,
				$deprecatedDescription,
				$isDeprecated,
				$isInternal,
				$isPure,
				$acceptsNamedArguments,
				$asserts ?? Assertions::createEmpty(),
				$phpDocComment,
				array_map(static fn (Type $type): Type => TemplateTypeHelper::toArgument($type), $parameterOutTypes),
				$immediatelyInvokedCallableParameters,
				$phpDocClosureThisTypeParameters,
				$this->services->attributeReflectionFactory->fromAttrGroups($function->attrGroups, InitializerExprContext::fromStubParameter(null, $this->getFile(), $function)),
				$pureUnlessCallableIsImpureParameters,
				$pureUnlessParameterPassedParameters,
			),
			false,
		);
	}

	private function enterFunctionLike(
		PhpFunctionFromParserNodeReflection $functionReflection,
		bool $preserveConstructorScope,
	): self
	{
		$parametersByName = [];

		$functionParameters = $functionReflection->getParameters();
		foreach ($functionParameters as $parameter) {
			$parametersByName[$parameter->getName()] = $parameter;
		}

		$expressionTypes = [];
		$nativeExpressionTypes = [];
		$conditionalTypes = [];

		if ($preserveConstructorScope) {
			$expressionTypes = $this->expressionTypes;
			$nativeExpressionTypes = $this->nativeExpressionTypes;
		}

		foreach ($functionParameters as $parameter) {
			$parameterType = $parameter->getType();

			if ($parameterType instanceof ConditionalTypeForParameter) {
				$targetParameterName = substr($parameterType->getParameterName(), 1);
				if (array_key_exists($targetParameterName, $parametersByName)) {
					$targetParameter = $parametersByName[$targetParameterName];

					$ifType = $parameterType->isNegated() ? $parameterType->getElse() : $parameterType->getIf();
					$elseType = $parameterType->isNegated() ? $parameterType->getIf() : $parameterType->getElse();

					$holder = new ConditionalExpressionHolder([
						$parameterType->getParameterName() => ExpressionTypeHolder::createYes(new Variable($targetParameterName), TypeCombinator::intersect($targetParameter->getType(), $parameterType->getTarget())),
					], ExpressionTypeHolder::createYes(new Variable($parameter->getName()), $ifType));
					$conditionalTypes['$' . $parameter->getName()][$holder->getKey()] = $holder;

					$holder = new ConditionalExpressionHolder([
						$parameterType->getParameterName() => ExpressionTypeHolder::createYes(new Variable($targetParameterName), TypeCombinator::remove($targetParameter->getType(), $parameterType->getTarget())),
					], ExpressionTypeHolder::createYes(new Variable($parameter->getName()), $elseType));
					$conditionalTypes['$' . $parameter->getName()][$holder->getKey()] = $holder;
				}
			}

			$paramExprString = '$' . $parameter->getName();
			if ($parameter->isVariadic()) {
				if (!$this->getPhpVersion()->supportsNamedArguments()->no() && $functionReflection->acceptsNamedArguments()->yes()) {
					$parameterType = new ArrayType(new UnionType([IntegerRangeType::createAllGreaterThanOrEqualTo(0), new StringType()]), $parameterType);
				} else {
					$parameterType = new IntersectionType([new ArrayType(IntegerRangeType::createAllGreaterThanOrEqualTo(0), $parameterType), new AccessoryArrayListType()]);
				}
			}
			$parameterNode = new Variable($parameter->getName());
			$expressionTypes[$paramExprString] = ExpressionTypeHolder::createYes($parameterNode, $parameterType);

			$parameterOriginalValueExpr = new ParameterVariableOriginalValueExpr($parameter->getName());
			$parameterOriginalValueExprString = $this->getNodeKey($parameterOriginalValueExpr);
			$expressionTypes[$parameterOriginalValueExprString] = ExpressionTypeHolder::createYes($parameterOriginalValueExpr, $parameterType);

			$nativeParameterType = $parameter->getNativeType();
			if ($parameter->isVariadic()) {
				if (!$this->getPhpVersion()->supportsNamedArguments()->no() && $functionReflection->acceptsNamedArguments()->yes()) {
					$nativeParameterType = new ArrayType(new UnionType([IntegerRangeType::createAllGreaterThanOrEqualTo(0), new StringType()]), $nativeParameterType);
				} else {
					$nativeParameterType = new IntersectionType([new ArrayType(IntegerRangeType::createAllGreaterThanOrEqualTo(0), $nativeParameterType), new AccessoryArrayListType()]);
				}
			}
			$nativeExpressionTypes[$paramExprString] = ExpressionTypeHolder::createYes($parameterNode, $nativeParameterType);
			$nativeExpressionTypes[$parameterOriginalValueExprString] = ExpressionTypeHolder::createYes($parameterOriginalValueExpr, $nativeParameterType);
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$functionReflection,
			$this->getNamespace(),
			array_merge($this->getConstantTypes(), $expressionTypes),
			array_merge($this->getNativeConstantTypes(), $nativeExpressionTypes),
			$conditionalTypes,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	/** @api */
	public function enterNamespace(string $namespaceName): self
	{
		return $this->scopeFactory->create(
			$this->context->beginFile(),
			$this->isDeclareStrictTypes(),
			null,
			$namespaceName,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	/**
	 * @param list<non-empty-string> $scopeClasses
	 */
	public function enterClosureBind(?Type $thisType, ?Type $nativeThisType, array $scopeClasses): self
	{
		$expressionTypes = $this->expressionTypes;
		if ($thisType !== null) {
			$expressionTypes['$this'] = ExpressionTypeHolder::createYes(new Variable('this'), $thisType);
		} else {
			unset($expressionTypes['$this']);
		}

		$nativeExpressionTypes = $this->nativeExpressionTypes;
		if ($nativeThisType !== null) {
			$nativeExpressionTypes['$this'] = ExpressionTypeHolder::createYes(new Variable('this'), $nativeThisType);
		} else {
			unset($nativeExpressionTypes['$this']);
		}

		if ($scopeClasses === ['static'] && $this->isInClass()) {
			$scopeClasses = [$this->getClassReflection()->getName()];
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$scopeClasses,
			$this->anonymousFunctionReflection,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	public function restoreOriginalScopeAfterClosureBind(self $originalScope): self
	{
		$expressionTypes = $this->expressionTypes;
		if (isset($originalScope->expressionTypes['$this'])) {
			$expressionTypes['$this'] = $originalScope->expressionTypes['$this'];
		} else {
			unset($expressionTypes['$this']);
		}

		$nativeExpressionTypes = $this->nativeExpressionTypes;
		if (isset($originalScope->nativeExpressionTypes['$this'])) {
			$nativeExpressionTypes['$this'] = $originalScope->nativeExpressionTypes['$this'];
		} else {
			unset($nativeExpressionTypes['$this']);
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$originalScope->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	public function restoreThis(self $restoreThisScope): self
	{
		$expressionTypes = $this->expressionTypes;
		$nativeExpressionTypes = $this->nativeExpressionTypes;

		if ($restoreThisScope->isInClass()) {
			foreach ($restoreThisScope->expressionTypes as $exprString => $expressionTypeHolder) {
				if (!str_starts_with($exprString, '$this')) {
					continue;
				}

				$expressionTypes[$exprString] = $expressionTypeHolder;
			}

			foreach ($restoreThisScope->nativeExpressionTypes as $exprString => $expressionTypeHolder) {
				if (!str_starts_with($exprString, '$this')) {
					continue;
				}

				$nativeExpressionTypes[$exprString] = $expressionTypeHolder;
			}
		} else {
			unset($expressionTypes['$this']);
			unset($nativeExpressionTypes['$this']);
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$restoreThisScope->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			[],
			[],
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	public function enterClosureCall(Type $thisType, Type $nativeThisType): self
	{
		$expressionTypes = $this->expressionTypes;
		$expressionTypes['$this'] = ExpressionTypeHolder::createYes(new Variable('this'), $thisType);

		$nativeExpressionTypes = $this->nativeExpressionTypes;
		$nativeExpressionTypes['$this'] = ExpressionTypeHolder::createYes(new Variable('this'), $nativeThisType);

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$thisType->getObjectClassNames(),
			$this->anonymousFunctionReflection,
			templateArgumentFrame: $this->templateArgumentFrame,
			templateArgumentConstraints: $this->templateArgumentConstraints,
		);
	}

	/** @api */
	public function isInClosureBind(): bool
	{
		return $this->inClosureBindScopeClasses !== [];
	}

	/**
	 * @param list<non-empty-string> $scopeClasses
	 */
	public function withClosureBindScopeClasses(array $scopeClasses): self
	{
		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$scopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * @api
	 * @param ParameterReflection[]|null $callableParameters
	 * @param ParameterReflection[]|null $nativeCallableParameters
	 */
	public function enterAnonymousFunction(
		Expr\Closure $closure,
		?array $callableParameters,
		?array $nativeCallableParameters = null,
	): self
	{
		$anonymousFunctionReflection = $this->services->container->getByType(ClosureTypeResolver::class)->getClosureType($this, $closure, true, $this->getCurrentExpressionResultStorage());

		$scope = $this->enterAnonymousFunctionWithoutReflection($closure, $callableParameters, $nativeCallableParameters);

		return $this->scopeFactory->create(
			$scope->context,
			$scope->isDeclareStrictTypes(),
			$scope->getFunction(),
			$scope->getNamespace(),
			$scope->expressionTypes,
			$scope->nativeExpressionTypes,
			$scope->conditionalExpressions,
			$scope->inClosureBindScopeClasses,
			$anonymousFunctionReflection,
			true,
			[],
			[],
			$this->inFunctionCallsStack,
			false,
			$this,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * @param ParameterReflection[]|null $callableParameters
	 * @param ParameterReflection[]|null $nativeCallableParameters
	 */
	public function enterAnonymousFunctionWithoutReflection(
		Expr\Closure $closure,
		?array $callableParameters,
		?array $nativeCallableParameters,
	): self
	{
		$expressionTypes = [];
		$nativeTypes = [];
		foreach ($closure->params as $i => $parameter) {
			if (!$parameter->var instanceof Variable || !is_string($parameter->var->name)) {
				throw new ShouldNotHappenException();
			}
			$paramExprString = sprintf('$%s', $parameter->var->name);
			$isNullable = $this->isParameterValueNullable($parameter);
			$nativeParameterType = $parameterType = $this->getFunctionType($parameter->type, $isNullable, $parameter->variadic);
			if ($callableParameters !== null) {
				$parameterType = self::intersectButNotNever($parameterType, $this->getCallableParameterType($parameter, $callableParameters, $i));
			}
			if ($nativeCallableParameters !== null) {
				$nativeParameterType = self::intersectButNotNever($nativeParameterType, $this->getCallableParameterType($parameter, $nativeCallableParameters, $i));
			}
			$expressionTypes[$paramExprString] = ExpressionTypeHolder::createYes($parameter->var, $parameterType);
			$nativeTypes[$paramExprString] = ExpressionTypeHolder::createYes($parameter->var, $nativeParameterType);
		}

		$nonRefVariableNames = [];
		$useVariableNames = [];
		foreach ($closure->uses as $use) {
			if (!is_string($use->var->name)) {
				throw new ShouldNotHappenException();
			}
			$variableName = $use->var->name;
			$paramExprString = '$' . $use->var->name;
			$useVariableNames[$paramExprString] = true;
			if ($use->byRef) {
				$holder = ExpressionTypeHolder::createYes($use->var, new MixedType());
				$expressionTypes[$paramExprString] = $holder;
				$nativeTypes[$paramExprString] = $holder;
				continue;
			}
			$nonRefVariableNames[$variableName] = true;
			if ($this->hasVariableType($variableName)->no()) {
				$variableType = new ErrorType();
				$variableNativeType = new ErrorType();
			} else {
				$variableType = $this->getVariableType($variableName);
				// a plain variable read is scope state - never priced via the
				// node, which may not have been processed yet
				$nativeScope = $this->doNotTreatPhpDocTypesAsCertain();
				$variableNativeType = $nativeScope->hasVariableType($variableName)->no() ? new ErrorType() : $nativeScope->getVariableType($variableName);
			}
			$expressionTypes[$paramExprString] = ExpressionTypeHolder::createYes($use->var, $variableType);
			$nativeTypes[$paramExprString] = ExpressionTypeHolder::createYes($use->var, $variableNativeType);
		}

		$nonStaticExpressions = $this->invalidateStaticExpressions($this->expressionTypes);
		foreach ($nonStaticExpressions as $exprString => $typeHolder) {
			$expr = $typeHolder->getExpr();

			if ($expr instanceof Variable) {
				continue;
			}

			$variables = (new NodeFinder())->findInstanceOf([$expr], Variable::class);
			if ($variables === [] && !$this->expressionTypeIsUnchangeable($typeHolder)) {
				continue;
			}

			foreach ($variables as $variable) {
				if (!is_string($variable->name)) {
					continue 2;
				}
				if (!array_key_exists($variable->name, $nonRefVariableNames)) {
					continue 2;
				}
			}

			$expressionTypes[$exprString] = $typeHolder;
		}

		if ($this->hasVariableType('this')->yes() && !$closure->static) {
			$node = new Variable('this');
			$expressionTypes['$this'] = ExpressionTypeHolder::createYes($node, $this->getType($node));
			$nativeTypes['$this'] = ExpressionTypeHolder::createYes($node, $this->getNativeType($node));

			if ($this->services->phpVersion->supportsReadOnlyProperties()) {
				foreach ($nonStaticExpressions as $exprString => $typeHolder) {
					$expr = $typeHolder->getExpr();

					if (!$expr instanceof PropertyFetch) {
						continue;
					}

					if (!$this->isReadonlyPropertyFetch($expr, true)) {
						continue;
					}

					$expressionTypes[$exprString] = $typeHolder;
				}
			}
		}

		$filteredConditionalExpressions = [];
		foreach ($this->conditionalExpressions as $conditionalExprString => $holders) {
			if (!array_key_exists($conditionalExprString, $useVariableNames)) {
				continue;
			}
			$filteredHolders = [];
			foreach ($holders as $key => $holder) {
				foreach (array_keys($holder->getConditionExpressionTypeHolders()) as $holderExprString) {
					if (!array_key_exists($holderExprString, $useVariableNames)) {
						continue 2;
					}
				}
				$filteredHolders[$key] = $holder;
			}
			if ($filteredHolders === []) {
				continue;
			}

			$filteredConditionalExpressions[$conditionalExprString] = $filteredHolders;
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			array_merge($this->getConstantTypes(), $expressionTypes),
			array_merge($this->getNativeConstantTypes(), $nativeTypes),
			$filteredConditionalExpressions,
			$this->inClosureBindScopeClasses,
			new ClosureType(),
			true,
			[],
			[],
			[],
			false,
			$this,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	private function expressionTypeIsUnchangeable(ExpressionTypeHolder $typeHolder): bool
	{
		$expr = $typeHolder->getExpr();
		$type = $typeHolder->getType();

		return $expr instanceof FuncCall
			&& !$expr->isFirstClassCallable()
			&& $expr->name instanceof FullyQualified
			&& in_array(
				$expr->name->toLowerString(),
				[
					'class_exists',
					'interface_exists',
					'trait_exists',
					'enum_exists',
					'function_exists',
				],
				true,
			)
			&& isset($expr->getArgs()[0])
			&& count($this->getScopeStateType($expr->getArgs()[0]->value)->getConstantStrings()) === 1
			&& $type->isTrue()->yes();
	}

	/**
	 * @param array<string, ExpressionTypeHolder> $expressionTypes
	 * @return array<string, ExpressionTypeHolder>
	 */
	private function invalidateStaticExpressions(array $expressionTypes): array
	{
		$filteredExpressionTypes = [];
		$nodeFinder = new NodeFinder();
		foreach ($expressionTypes as $exprString => $expressionType) {
			$staticExpression = $nodeFinder->findFirst(
				[$expressionType->getExpr()],
				static fn ($node) => $node instanceof Expr\StaticCall || $node instanceof Expr\StaticPropertyFetch,
			);
			if ($staticExpression !== null) {
				continue;
			}
			$filteredExpressionTypes[$exprString] = $expressionType;
		}
		return $filteredExpressionTypes;
	}

	/**
	 * @api
	 * @param ParameterReflection[]|null $callableParameters
	 * @param ParameterReflection[]|null $nativeCallableParameters
	 */
	public function enterArrowFunction(Expr\ArrowFunction $arrowFunction, ?array $callableParameters, ?array $nativeCallableParameters = null): self
	{
		$anonymousFunctionReflection = $this->services->container->getByType(ClosureTypeResolver::class)->getClosureType($this, $arrowFunction, true, $this->getCurrentExpressionResultStorage());

		$scope = $this->enterArrowFunctionWithoutReflection($arrowFunction, $callableParameters, $nativeCallableParameters);

		return $this->scopeFactory->create(
			$scope->context,
			$scope->isDeclareStrictTypes(),
			$scope->getFunction(),
			$scope->getNamespace(),
			$scope->expressionTypes,
			$scope->nativeExpressionTypes,
			$scope->conditionalExpressions,
			$scope->inClosureBindScopeClasses,
			$anonymousFunctionReflection,
			true,
			[],
			[],
			$this->inFunctionCallsStack,
			$scope->afterExtractCall,
			$scope->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * @param ParameterReflection[]|null $callableParameters
	 * @param ParameterReflection[]|null $nativeCallableParameters
	 */
	public function enterArrowFunctionWithoutReflection(Expr\ArrowFunction $arrowFunction, ?array $callableParameters, ?array $nativeCallableParameters): self
	{
		$arrowFunctionScope = $this;
		foreach ($arrowFunction->params as $i => $parameter) {
			$isNullable = $this->isParameterValueNullable($parameter);
			$nativeParameterType = $parameterType = $this->getFunctionType($parameter->type, $isNullable, $parameter->variadic);
			if ($callableParameters !== null) {
				$parameterType = self::intersectButNotNever($parameterType, $this->getCallableParameterType($parameter, $callableParameters, $i));
			}
			if ($nativeCallableParameters !== null) {
				$nativeParameterType = self::intersectButNotNever($nativeParameterType, $this->getCallableParameterType($parameter, $nativeCallableParameters, $i));
			}

			if (!$parameter->var instanceof Variable || !is_string($parameter->var->name)) {
				throw new ShouldNotHappenException();
			}
			$arrowFunctionScope = $arrowFunctionScope->assignVariable($parameter->var->name, $parameterType, $nativeParameterType, TrinaryLogic::createYes());
		}

		if ($arrowFunction->static) {
			$arrowFunctionScope = $arrowFunctionScope->invalidateExpression(new Variable('this'));
		}

		return $this->scopeFactory->create(
			$arrowFunctionScope->context,
			$this->isDeclareStrictTypes(),
			$arrowFunctionScope->getFunction(),
			$arrowFunctionScope->getNamespace(),
			$this->invalidateStaticExpressions($arrowFunctionScope->expressionTypes),
			$arrowFunctionScope->nativeExpressionTypes,
			$arrowFunctionScope->conditionalExpressions,
			$arrowFunctionScope->inClosureBindScopeClasses,
			new ClosureType(),
			true,
			[],
			[],
			[],
			$arrowFunctionScope->afterExtractCall,
			$arrowFunctionScope->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	public function isParameterValueNullable(Node\Param $parameter): bool
	{
		if ($parameter->default instanceof ConstFetch) {
			return strtolower((string) $parameter->default->name) === 'null';
		}

		return false;
	}

	/**
	 * @api
	 * @param Node\Name|Node\Identifier|Node\ComplexType|null $type
	 */
	public function getFunctionType($type, bool $isNullable, bool $isVariadic): Type
	{
		if ($isVariadic) {
			if (!$this->getPhpVersion()->supportsNamedArguments()->no()) {
				return new ArrayType(new UnionType([IntegerRangeType::createAllGreaterThanOrEqualTo(0), new StringType()]), $this->getFunctionType(
					$type,
					$isNullable,
					false,
				));
			}

			return new IntersectionType([new ArrayType(IntegerRangeType::createAllGreaterThanOrEqualTo(0), $this->getFunctionType(
				$type,
				$isNullable,
				false,
			)), new AccessoryArrayListType()]);
		}
		if (
			$type instanceof Name
			&& $this->inClosureBindScopeClasses !== []
			&& $this->inClosureBindScopeClasses !== ['static']
			&& in_array($type->toLowerString(), ['static', 'self', 'parent'], true)
			&& $this->services->reflectionProvider->hasClass($this->inClosureBindScopeClasses[0])
		) {
			return $this->services->initializerExprTypeResolver->getFunctionType(
				$type,
				$isNullable,
				false,
				InitializerExprContext::fromClassReflection(
					$this->services->reflectionProvider->getClass($this->inClosureBindScopeClasses[0]),
				),
			);
		}

		return $this->services->initializerExprTypeResolver->getFunctionType($type, $isNullable, false, InitializerExprContext::fromScope($this));
	}

	/**
	 * @param ParameterReflection[] $callableParameters
	 */
	private function getCallableParameterType(Node\Param $parameter, array $callableParameters, int $index): Type
	{
		if ($parameter->variadic) {
			return $this->buildVariadicArrayTypeFromCallableParameters($callableParameters, $index);
		}

		if (isset($callableParameters[$index])) {
			return $callableParameters[$index]->getType();
		}

		if (count($callableParameters) === 0) {
			return new MixedType();
		}

		$lastParameter = array_last($callableParameters);
		if ($lastParameter->isVariadic()) {
			return $lastParameter->getType();
		}

		return new MixedType();
	}

	/**
	 * @param array<ParameterReflection> $callableParameters
	 */
	private function buildVariadicArrayTypeFromCallableParameters(array $callableParameters, int $startIndex): Type
	{
		$elementTypes = [];
		$callableParametersCount = count($callableParameters);
		for ($j = $startIndex; $j < $callableParametersCount; $j++) {
			$elementTypes[] = $callableParameters[$j]->getType();
			if ($callableParameters[$j]->isVariadic()) {
				break;
			}
		}

		if ($elementTypes === [] && $callableParametersCount > 0) {
			$lastParameter = array_last($callableParameters);
			if ($lastParameter->isVariadic()) {
				$elementTypes[] = $lastParameter->getType();
			}
		}

		if ($elementTypes === []) {
			return new MixedType();
		}

		$elementType = TypeCombinator::union(...$elementTypes);

		if (!$this->getPhpVersion()->supportsNamedArguments()->no()) {
			return new ArrayType(new UnionType([IntegerRangeType::createAllGreaterThanOrEqualTo(0), new StringType()]), $elementType);
		}

		return new IntersectionType([new ArrayType(IntegerRangeType::createAllGreaterThanOrEqualTo(0), $elementType), new AccessoryArrayListType()]);
	}

	public static function intersectButNotNever(Type $nativeType, Type $inferredType): Type
	{
		if ($nativeType->isSuperTypeOf($inferredType)->no()) {
			return $nativeType;
		}

		$result = TypeCombinator::intersect($nativeType, $inferredType);
		if ($result instanceof NeverType) {
			// the inferred type says no value is ever produced - the native
			// type's nullability must not resurrect one
			return $result;
		}

		if (TypeCombinator::containsNull($nativeType)) {
			return TypeCombinator::addNull($result);
		}

		return $result;
	}

	public function enterMatch(Expr\Match_ $expr, Type $condType, Type $condNativeType): self
	{
		if ($expr->cond instanceof Variable) {
			return $this;
		}
		if ($expr->cond instanceof AlwaysRememberedExpr) {
			$cond = $expr->cond->expr;
		} else {
			$cond = $expr->cond;
		}
		if ($cond instanceof Scalar) {
			return $this;
		}

		$type = $condType;
		$nativeType = $condNativeType;
		$condExpr = new AlwaysRememberedExpr($cond, $type, $nativeType);
		$expr->cond = $condExpr;

		return $this->assignExpression($condExpr, $type, $nativeType);
	}

	public function enterForeach(self $originalScope, Expr $iteratee, Type $iterateeType, Type $nativeIterateeType, string $valueName, ?string $keyName, bool $valueByRef): self
	{
		$valueType = $originalScope->getIterableValueType($iterateeType);
		$nativeValueType = $originalScope->getIterableValueType($nativeIterateeType);
		$scope = $this->assignVariable(
			$valueName,
			$valueType,
			$nativeValueType,
			TrinaryLogic::createYes(),
		);
		// Track the original foreach value so narrowings applied to the value
		// variable (e.g. is_string($type)) can later be projected back onto the
		// corresponding array dim fetch without being confused by a reassignment
		// ($type = 'foo' invalidates this expression, same as OriginalForeachKeyExpr).
		$scope = $scope->assignExpression(new OriginalForeachValueExpr($valueName), $valueType, $nativeValueType);
		if ($valueByRef && $iterateeType->isArray()->yes() && $iterateeType->isConstantArray()->no()) {
			// the write-through rebuilds the iteratee AT FOREACH ENTRY with the
			// value variable's latest type - captured here, not read live: a
			// live read would union the transient mid-iteration value states
			// into the array (the loop convergence owns cross-iteration merging)
			$scope = $scope->assignExpression(
				new IntertwinedVariableByReferenceWithExpr($valueName, $iteratee, new SetExistingOffsetValueTypeExpr(
					new NativeTypeExpr($iterateeType, $nativeIterateeType),
					new NativeTypeExpr(
						$originalScope->getIterableKeyType($iterateeType),
						$originalScope->getIterableKeyType($nativeIterateeType),
					),
					new Variable($valueName),
				)),
				$valueType,
				$nativeValueType,
			);
		}
		if ($keyName !== null) {
			$scope = $scope->enterForeachKey($originalScope, $iteratee, $iterateeType, $nativeIterateeType, $keyName);

			if ($valueByRef && $iterateeType->isArray()->yes() && $iterateeType->isConstantArray()->no()) {
				$scope = $scope->assignExpression(
					new IntertwinedVariableByReferenceWithExpr($valueName, new Expr\ArrayDimFetch($iteratee, new Variable($keyName)), new Variable($valueName)),
					$valueType,
					$nativeValueType,
				);
			}
		}

		return $scope;
	}

	public function enterForeachKey(self $originalScope, Expr $iteratee, Type $iterateeType, Type $nativeIterateeType, string $keyName): self
	{
		$keyType = $originalScope->getIterableKeyType($iterateeType);
		$nativeKeyType = $originalScope->getIterableKeyType($nativeIterateeType);

		$scope = $this->assignVariable(
			$keyName,
			$keyType,
			$nativeKeyType,
			TrinaryLogic::createYes(),
		);

		$originalForeachKeyExpr = new OriginalForeachKeyExpr($keyName);
		$scope = $scope->assignExpression($originalForeachKeyExpr, $keyType, $nativeKeyType);
		if ($iterateeType->isArray()->yes()) {
			$scope = $scope->assignExpression(
				new Expr\ArrayDimFetch($iteratee, new Variable($keyName)),
				$originalScope->getIterableValueType($iterateeType),
				$originalScope->getIterableValueType($nativeIterateeType),
			);
		}

		return $scope;
	}

	public function enterCatchType(Type $catchType, ?string $variableName): self
	{
		if ($variableName === null) {
			return $this;
		}

		return $this->assignVariable(
			$variableName,
			TypeCombinator::intersect($catchType, new ObjectType(Throwable::class)),
			TypeCombinator::intersect($catchType, new ObjectType(Throwable::class)),
			TrinaryLogic::createYes(),
		);
	}

	public function enterExpressionAssign(Expr $expr, bool $isPlainWrite = true): self
	{
		$exprString = $this->getNodeKey($expr);
		$currentlyAssignedExpressions = $this->currentlyAssignedExpressions;
		$currentlyAssignedExpressions[$exprString] = $isPlainWrite;

		$scope = $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			[],
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
		$scope->resolvedTypes = $this->resolvedTypes;

		return $scope;
	}

	public function exitExpressionAssign(Expr $expr): self
	{
		$exprString = $this->getNodeKey($expr);
		$currentlyAssignedExpressions = $this->currentlyAssignedExpressions;
		unset($currentlyAssignedExpressions[$exprString]);

		$scope = $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			[],
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
		$scope->resolvedTypes = $this->resolvedTypes;

		return $scope;
	}

	/** @api */
	public function isInExpressionAssign(Expr $expr): bool
	{
		if (count($this->currentlyAssignedExpressions) === 0) {
			return false;
		}

		$exprString = $this->getNodeKey($expr);
		return array_key_exists($exprString, $this->currentlyAssignedExpressions);
	}

	/**
	 * Whether the expression is a plain write target of an assignment, as opposed to being
	 * read-modified in place (e.g. the base of `$prop[] = ...`). Used to decide whether a
	 * property fetch resolves to its writable or readable type.
	 */
	public function isInWriteExpressionAssign(Expr $expr): bool
	{
		if (count($this->currentlyAssignedExpressions) === 0) {
			return false;
		}

		$exprString = $this->getNodeKey($expr);
		return ($this->currentlyAssignedExpressions[$exprString] ?? false) === true;
	}

	public function setAllowedUndefinedExpression(Expr $expr): self
	{
		if ($expr instanceof Expr\StaticPropertyFetch) {
			return $this;
		}

		$exprString = $this->getNodeKey($expr);
		$currentlyAllowedUndefinedExpressions = $this->currentlyAllowedUndefinedExpressions;
		$currentlyAllowedUndefinedExpressions[$exprString] = true;

		$scope = $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$currentlyAllowedUndefinedExpressions,
			[],
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
		$scope->resolvedTypes = $this->resolvedTypes;

		return $scope;
	}

	public function unsetAllowedUndefinedExpression(Expr $expr): self
	{
		$exprString = $this->getNodeKey($expr);
		$currentlyAllowedUndefinedExpressions = $this->currentlyAllowedUndefinedExpressions;
		unset($currentlyAllowedUndefinedExpressions[$exprString]);

		$scope = $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->isInFirstLevelStatement(),
			$this->currentlyAssignedExpressions,
			$currentlyAllowedUndefinedExpressions,
			[],
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
		$scope->resolvedTypes = $this->resolvedTypes;

		return $scope;
	}

	/** @api */
	public function isUndefinedExpressionAllowed(Expr $expr): bool
	{
		if (count($this->currentlyAllowedUndefinedExpressions) === 0) {
			return false;
		}
		$exprString = $this->getNodeKey($expr);
		return array_key_exists($exprString, $this->currentlyAllowedUndefinedExpressions);
	}

	/**
	 * @param list<string> $intertwinedPropagatedFrom
	 */
	public function assignVariable(string $variableName, Type $type, Type $nativeType, TrinaryLogic $certainty, array $intertwinedPropagatedFrom = []): self
	{
		$node = new Variable($variableName);
		$scope = $this->assignExpression($node, $type, $nativeType);
		if ($certainty->no()) {
			throw new ShouldNotHappenException();
		} elseif (!$certainty->yes()) {
			$exprString = '$' . $variableName;
			$scope->expressionTypes[$exprString] = new ExpressionTypeHolder($node, $type, $certainty);
			$scope->nativeExpressionTypes[$exprString] = new ExpressionTypeHolder($node, $nativeType, $certainty);
		}

		foreach ($scope->expressionTypes as $exprString => $expressionType) {
			if (!$expressionType->getExpr() instanceof IntertwinedVariableByReferenceWithExpr) {
				continue;
			}
			if (!$expressionType->getCertainty()->yes()) {
				continue;
			}
			if ($expressionType->getExpr()->getVariableName() !== $variableName) {
				continue;
			}

			$assignedExpr = $expressionType->getExpr()->getAssignedExpr();
			if (
				$assignedExpr instanceof Expr\ArrayDimFetch
				&& !$this->isDimFetchPathReachable($scope, $assignedExpr)
			) {
				unset($scope->expressionTypes[$exprString]);
				unset($scope->nativeExpressionTypes[$exprString]);
				continue;
			}

			// When the byref's dim is non-constant AND not enumerable as a
			// finite set of scalars (e.g. general `int` or `mixed`), the just-
			// performed write to $array might or might not have hit the byref's
			// slot. Union the new $array[dim] read with the byref's previous
			// type and the pre-write $array[dim] so values that could still be
			// at the slot (unmodified or shadowed by an explicit-key overwrite)
			// survive. For finitely-enumerable dims (e.g. `bool`, `int<0, 5>`)
			// the array literal builder enumerates all possibilities, so the
			// new $array[dim] read already covers every reachable slot.
			$unionWithOld = false;
			if ($assignedExpr instanceof Expr\ArrayDimFetch && $assignedExpr->dim !== null) {
				$dimType = $scope->getType($assignedExpr->dim);
				if (count($dimType->getConstantScalarValues()) !== 1 && count($dimType->getFiniteTypes()) === 0) {
					$unionWithOld = true;
				}
			}

			// Resolve the byref slot's new value directly from the just-assigned
			// root variable's type, instead of re-evaluating the (stale) $assignedExpr
			// node via Scope::getType(): the stored ArrayDimFetch result captured the
			// array variable before it existed, so re-reading it would only resolve
			// through the asking scope. We already hold the authoritative value here.
			$assignedType = $this->resolveIntertwinedAssignedType($scope, $type, $assignedExpr, $variableName, false);
			$assignedNativeType = $this->resolveIntertwinedAssignedType($scope, $nativeType, $assignedExpr, $variableName, true);

			$has = $scope->hasExpressionType($expressionType->getExpr()->getExpr());
			if (
				$expressionType->getExpr()->getExpr() instanceof Variable
				&& is_string($expressionType->getExpr()->getExpr()->name)
				&& !$has->no()
			) {
				$targetVarName = $expressionType->getExpr()->getExpr()->name;
				if (in_array($targetVarName, $intertwinedPropagatedFrom, true)) {
					continue;
				}
				if ($unionWithOld) {
					$targetVarNode = new Variable($targetVarName);
					$rootVarNode = new Variable($variableName);
					$assignedType = TypeCombinator::union(
						$assignedType,
						$this->resolveIntertwinedAssignedType($this, $this->getType($rootVarNode), $assignedExpr, $variableName, false),
						$scope->getType($targetVarNode),
					);
					$assignedNativeType = TypeCombinator::union(
						$assignedNativeType,
						$this->resolveIntertwinedAssignedType($this, $this->getNativeType($rootVarNode), $assignedExpr, $variableName, true),
						$scope->getNativeType($targetVarNode),
					);
				}
				$scope = $scope->assignVariable(
					$targetVarName,
					$assignedType,
					$assignedNativeType,
					$has,
					array_merge($intertwinedPropagatedFrom, [$variableName]),
				);
			} else {
				$targetRootVar = ScopeOps::getIntertwinedRefRootVariableName($expressionType->getExpr()->getExpr());
				if ($targetRootVar !== null && in_array($targetRootVar, $intertwinedPropagatedFrom, true)) {
					continue;
				}
				$scope = $scope->overwriteExpression(
					$expressionType->getExpr()->getExpr(),
					$assignedType,
					$assignedNativeType,
				);
			}
		}

		return $scope;
	}

	/**
	 * assignExpression() for a value that overwrites what an already existing
	 * offset holds - a byref alias write or a setAlwaysOverwriteTypes()
	 * specification.
	 *
	 * For an `ArrayDimFetch` the new value has to be *written* into the containing
	 * array. assignExpression() would instead narrow it: specifyExpressionType()
	 * intersects the parent with HasOffsetValueType(dim, newValue), which
	 * contradicts - and collapses to `never` - a parent still holding the offset's
	 * previous (constant) value.
	 */
	private function overwriteExpression(Expr $expr, Type $type, Type $nativeType): self
	{
		if (!$expr instanceof Expr\ArrayDimFetch || $expr->dim === null) {
			return $this->assignExpression($expr, $type, $nativeType);
		}

		$dimType = $this->getType($expr->dim);
		$scope = $this->overwriteExpression(
			$expr->var,
			$this->getType($expr->var)->setExistingOffsetValueType($dimType, $type),
			$this->getNativeType($expr->var)->setExistingOffsetValueType($dimType, $nativeType),
		);

		return $scope->specifyExpressionType($expr, $type, $nativeType, TrinaryLogic::createYes());
	}

	/**
	 * Resolves the type of a byref slot expression (rooted at $rootVariableName)
	 * from $rootType - the type just assigned to that root variable - by walking
	 * the offsets, without re-evaluating the stored $assignedExpr node via
	 * Scope::getType().
	 */
	private function resolveIntertwinedAssignedType(self $scope, Type $rootType, Expr $assignedExpr, string $rootVariableName, bool $native): Type
	{
		if ($assignedExpr instanceof Variable && is_string($assignedExpr->name) && $assignedExpr->name === $rootVariableName) {
			return $rootType;
		}

		if ($assignedExpr instanceof Expr\ArrayDimFetch && $assignedExpr->dim !== null) {
			return $this->resolveIntertwinedAssignedType($scope, $rootType, $assignedExpr->var, $rootVariableName, $native)
				->getOffsetValueType($native ? $scope->getNativeType($assignedExpr->dim) : $scope->getType($assignedExpr->dim));
		}

		if ($assignedExpr instanceof SetExistingOffsetValueTypeExpr) {
			// foreach-byref slot: the iteratee with its key offset set to the value
			// variable's new type ($rootType is exactly that value - the expr's
			// getValue()).
			$iterateeType = $native
				? $scope->getNativeType($assignedExpr->getVar())
				: $scope->getType($assignedExpr->getVar());

			$dimType = $native
				? $scope->getNativeType($assignedExpr->getDim())
				: $scope->getType($assignedExpr->getDim());

			return $iterateeType->setExistingOffsetValueType($dimType, $rootType);
		}

		throw new ShouldNotHappenException();
	}

	private function isDimFetchPathReachable(self $scope, Expr\ArrayDimFetch $dimFetch): bool
	{
		if ($dimFetch->dim === null) {
			return false;
		}

		if (!$dimFetch->var instanceof Expr\ArrayDimFetch) {
			return true;
		}

		$varType = $scope->getType($dimFetch->var);
		$dimType = $scope->getType($dimFetch->dim);

		if (!$varType->hasOffsetValueType($dimType)->yes()) {
			return false;
		}

		return $this->isDimFetchPathReachable($scope, $dimFetch->var);
	}

	private function unsetExpression(Expr $expr): self
	{
		$scope = $this;
		if ($expr instanceof Expr\ArrayDimFetch && $expr->dim !== null) {
			$exprVarType = $scope->getScopeStateType($expr->var);
			$dimType = $scope->getType($expr->dim);
			$unsetType = $exprVarType->unsetOffset($dimType);
			$exprVarNativeType = $scope->getScopeStateNativeType($expr->var);
			$dimNativeType = $scope->getNativeType($expr->dim);
			$unsetNativeType = $exprVarNativeType->unsetOffset($dimNativeType);
			$scope = $scope->assignExpression($expr->var, $unsetType, $unsetNativeType)->invalidateExpression(
				new FuncCall(new FullyQualified('count'), [new Arg($expr->var)]),
			)->invalidateExpression(
				new FuncCall(new FullyQualified('sizeof'), [new Arg($expr->var)]),
			)->invalidateExpression(
				new FuncCall(new Name('count'), [new Arg($expr->var)]),
			)->invalidateExpression(
				new FuncCall(new Name('sizeof'), [new Arg($expr->var)]),
			);

			if ($expr->var instanceof Expr\ArrayDimFetch && $expr->var->dim !== null) {
				$scope = $scope->assignExpression(
					$expr->var->var,
					$this->getType($expr->var->var)->setOffsetValueType(
						$scope->getType($expr->var->dim),
						$scope->getScopeStateType($expr->var),
					),
					$this->getNativeType($expr->var->var)->setOffsetValueType(
						$scope->getNativeType($expr->var->dim),
						$scope->getScopeStateNativeType($expr->var),
					),
				);
			}
		}

		return $scope->invalidateExpression($expr);
	}

	/**
	 * A narrowable expression's current type as this scope sees it, derived
	 * from tracked state (recursing into operands via reflection/offset reads)
	 * - never by processing the node. The flavour follows the scope: a
	 * native-promoted scope answers native types. Non-narrowable expressions
	 * (calls, constants) fall back to getType().
	 */
	public function getStateType(Expr $expr): Type
	{
		return $this->resolveScopeStateType($expr, $this->nativeTypesPromoted);
	}

	private function getScopeStateType(Expr $expr): Type
	{
		return $this->resolveScopeStateType($expr, false);
	}

	private function getScopeStateNativeType(Expr $expr): Type
	{
		return $this->resolveScopeStateType($expr, true);
	}

	/**
	 * Reads a narrowable expression's current type from the scope's tracked
	 * state (recursing into its operands), instead of routing through the stored
	 * ExpressionResult callbacks - so it reflects narrowings and assignments
	 * applied to this scope rather than the expression's original evaluation
	 * point (where Variable callbacks would read their captured beforeScope).
	 */
	private function resolveScopeStateType(Expr $expr, bool $native): Type
	{
		if (!$expr instanceof Variable && $this->hasExpressionType($expr)->yes()) {
			// mirror resolveType()'s tracked-holder lookup without pricing the
			// node - the tracked type IS scope state (the extension hook is
			// deliberately skipped, like the getVariableType() read below)
			$askScope = $native ? $this->doNotTreatPhpDocTypesAsCertain() : $this;
			$trackedType = ScopeOps::expressionTypeByKey($askScope, $expr, $askScope->getNodeKey($expr));
			if ($trackedType !== null) {
				return TypeUtils::resolveLateResolvableTypes($trackedType);
			}

			return $native ? $this->getNativeType($expr) : $this->getType($expr);
		}

		if ($expr instanceof Variable && is_string($expr->name)) {
			$scope = $native ? $this->doNotTreatPhpDocTypesAsCertain() : $this;

			return $scope->hasVariableType($expr->name)->no() ? new ErrorType() : $scope->getVariableType($expr->name);
		}

		if ($expr instanceof Expr\ArrayDimFetch && $expr->dim !== null) {
			$varStateType = $this->resolveScopeStateType($expr->var, $native);
			if ($varStateType instanceof NeverType) {
				// real pricing of an offset read on never yields ErrorType (a
				// benevolent mixed), never NeverType - mirror it, or a narrowing
				// applied in a dead branch intersects its type against never and
				// loses it (e.g. is_object($x[0]) no longer tracks $x[0] as object,
				// silencing rules that read the narrowed type)
				return new ErrorType();
			}

			return $varStateType->getOffsetValueType($this->resolveScopeStateType($expr->dim, $native));
		}

		if ($expr instanceof PropertyFetch && $expr->name instanceof Identifier) {
			$propertyReflection = $this->getInstancePropertyReflection(
				$this->resolveScopeStateType($expr->var, $native),
				$expr->name->toString(),
			);
			if ($propertyReflection === null) {
				return new ErrorType();
			}

			if ($native) {
				return $propertyReflection->hasNativeType() ? $propertyReflection->getNativeType() : new MixedType();
			}

			return $propertyReflection->getReadableType();
		}

		if ($expr instanceof Expr\StaticPropertyFetch && $expr->name instanceof Node\VarLikeIdentifier) {
			$fetchedOnType = $expr->class instanceof Name
				? $this->resolveTypeByName($expr->class)
				: TypeCombinator::removeNull($this->resolveScopeStateType($expr->class, $native))->getObjectTypeOrClassStringObjectType();
			$propertyReflection = $this->getStaticPropertyReflection($fetchedOnType, $expr->name->toString());
			if ($propertyReflection === null) {
				return new ErrorType();
			}

			if ($native) {
				return $propertyReflection->hasNativeType() ? $propertyReflection->getNativeType() : new MixedType();
			}

			return $propertyReflection->getReadableType();
		}

		// a nullsafe link of a chain being ensured non-null ahead of its walk
		// (isset()/empty()/?? over `$a?->b()?->c`): its state is the plain
		// link's state on the receiver's state, plus the short-circuit null -
		// the same reflection-derived read as the plain fetch/call arms below,
		// never a walk of the still-unprocessed node
		if ($expr instanceof Expr\NullsafePropertyFetch && $expr->name instanceof Identifier) {
			return TypeCombinator::addNull($this->resolveScopeStateType(new PropertyFetch($expr->var, $expr->name), $native));
		}
		if (
			$expr instanceof Expr\NullsafeMethodCall
			&& $expr->name instanceof Identifier
			&& !$expr->isFirstClassCallable()
			&& $expr->getArgs() === []
		) {
			$attributes = $expr->getAttributes();
			unset($attributes[ExprPrinter::ATTRIBUTE_CACHE_KEY]);
			return TypeCombinator::addNull($this->resolveScopeStateType(new Expr\MethodCall($expr->var, $expr->name, attributes: $attributes), $native));
		}

		// an argument-less instance call - the shape @phpstan-assert subjects
		// take (synthetic nodes built fresh from the assert tag, never stored):
		// its declared return type on the receiver's state is the narrowing
		// base, derived from reflection instead of walking the synthetic node.
		// A call the walk did store answers from that result: the declared
		// return type lacks what the walk resolved against the arguments (a
		// conditional return type, a template, a dynamic return type extension)
		if (
			$expr instanceof Expr\MethodCall
			&& $expr->name instanceof Identifier
			&& !$expr->isFirstClassCallable()
			&& $expr->getArgs() === []
		) {
			$storage = $this->services->expressionResultStorageStack->getCurrent();
			if ($storage !== null && $storage->findExpressionResult($expr) !== null) {
				return $native ? $this->getNativeType($expr) : $this->getType($expr);
			}

			$methodReflection = $this->getMethodReflection(
				$this->resolveScopeStateType($expr->var, $native),
				$expr->name->toString(),
			);
			if ($methodReflection === null) {
				return new ErrorType();
			}

			// resolved against the (empty) argument list so a template inferred
			// from an omitted parameter's default resolves the way a walk
			// resolves it (Collection::first()'s TFirstDefault -> null)
			$variant = ParametersAcceptorSelector::selectFromArgs($this, [], $methodReflection->getVariants(), $methodReflection->getNamedArgumentsVariants());

			return $native && $variant instanceof ExtendedParametersAcceptor ? $variant->getNativeReturnType() : TemplateArgumentFrame::returnTypeOfCall($variant, $this, $expr, true);
		}

		// position-independent constant expressions (isset()/?? dimensions and
		// narrowing subjects like self::KEY) are priced without walking the node
		if (
			$expr instanceof Node\Scalar\String_
			|| $expr instanceof Node\Scalar\Int_
			|| $expr instanceof Node\Scalar\Float_
			|| ($expr instanceof Expr\ClassConstFetch && $expr->class instanceof Name && $expr->name instanceof Identifier)
			|| $expr instanceof ConstFetch
		) {
			return $this->services->initializerExprTypeResolver->getType($expr, InitializerExprContext::fromScope($this));
		}

		// genuinely non-narrowed expressions (calls, ...) have no
		// variable-callback hazard, so read them normally.
		return $native ? $this->getNativeType($expr) : $this->getType($expr);
	}

	public function specifyExpressionType(Expr $expr, Type $type, Type $nativeType, TrinaryLogic $certainty): self
	{
		if ($this->isSpecifyExpressionTypeNoop($expr, $type)) {
			return $this;
		}

		$scope = $this->openSpecificationScope();
		$scope->specifyExpressionTypeInPlace($expr, $type, $nativeType, $certainty);

		return $scope;
	}

	/** An unpublished copy of this scope that in-place specification may mutate. */
	private function openSpecificationScope(): self
	{
		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	private function isSpecifyExpressionTypeNoop(Expr $expr, Type $type): bool
	{
		if ($expr instanceof Scalar) {
			return true;
		}

		if ($expr instanceof ConstFetch) {
			$loweredConstName = strtolower($expr->name->toString());
			if (in_array($loweredConstName, ['true', 'false', 'null'], true)) {
				return true;
			}
		}

		if ($expr instanceof FuncCall && $expr->name instanceof Name && $type->isFalse()->yes()) {
			$functionName = $this->services->reflectionProvider->resolveFunctionName($expr->name, $this);
			if ($functionName !== null && in_array(strtolower($functionName), [
				'is_dir',
				'is_file',
				'file_exists',
			], true)) {
				return true;
			}
		}

		return false;
	}

	/**
	 * The body of specifyExpressionType() writing straight into this scope's
	 * holder maps - only to be called on an unpublished scope (see
	 * openSpecificationScope()). Batching callers avoid one whole-map copy and
	 * scope construction per specification (and per array-dim level).
	 */
	private function specifyExpressionTypeInPlace(Expr $expr, Type $type, Type $nativeType, TrinaryLogic $certainty): void
	{
		if ($this->isSpecifyExpressionTypeNoop($expr, $type)) {
			return;
		}

		if (
			$expr instanceof Expr\ArrayDimFetch
			&& $expr->dim !== null
			&& !$expr->dim instanceof Expr\PreInc
			&& !$expr->dim instanceof Expr\PreDec
			&& !$expr->dim instanceof Expr\PostDec
			&& !$expr->dim instanceof Expr\PostInc
		) {
			$dimType = $this->getScopeStateType($expr->dim)->toArrayKey();
			if ($dimType->isInteger()->yes() || $dimType->isString()->yes()) {
				$exprVarType = $this->getScopeStateType($expr->var);
				$isArray = $exprVarType->isArray();
				if (!$exprVarType instanceof MixedType && !$isArray->no()) {
					$varType = $exprVarType;
					if (!$isArray->yes()) {
						if ($dimType->isInteger()->yes()) {
							$varType = TypeCombinator::intersect($exprVarType, StaticTypeFactory::intOffsetAccessibleType());
						} else {
							$varType = TypeCombinator::intersect($exprVarType, StaticTypeFactory::generalOffsetAccessibleType());
						}
					}

					if ($dimType instanceof ConstantIntegerType || $dimType instanceof ConstantStringType) {
						if (!$this->isComplexUnionType($varType)) {
							$varType = TypeCombinator::intersect(
								$varType,
								new HasOffsetValueType($dimType, $type),
							);
						}
					}

					$this->specifyExpressionTypeInPlace(
						$expr->var,
						$varType,
						$this->getScopeStateNativeType($expr->var),
						$certainty,
					);
				}
			}
		}

		if ($certainty->no()) {
			throw new ShouldNotHappenException();
		}

		$exprString = $this->getNodeKey($expr);
		$this->expressionTypes[$exprString] = new ExpressionTypeHolder($expr, $type, $certainty);
		$this->nativeExpressionTypes[$exprString] = new ExpressionTypeHolder($expr, $nativeType, $certainty);

		if (!($expr instanceof AlwaysRememberedExpr)) {
			return;
		}

		$this->specifyExpressionTypeInPlace($expr->expr, $type, $nativeType, $certainty);
	}

	public function assignExpression(Expr $expr, Type $type, Type $nativeType): self
	{
		$scope = $this;
		if ($expr instanceof PropertyFetch) {
			$scope = $this->invalidateExpression($expr)
				->invalidateMethodsOnExpression($expr->var);
		} elseif ($expr instanceof Expr\StaticPropertyFetch) {
			$scope = $this->invalidateExpression($expr);
		} elseif ($expr instanceof Variable) {
			$scope = $this->invalidateExpression($expr);
		}

		return $scope->specifyExpressionType($expr, $type, $nativeType, TrinaryLogic::createYes());
	}

	public function assignInitializedProperty(Type $fetchedOnType, string $propertyName): self
	{
		if (!$this->isInClass()) {
			return $this;
		}

		if (TypeUtils::findThisType($fetchedOnType) === null) {
			return $this;
		}

		$propertyReflection = $this->getInstancePropertyReflection($fetchedOnType, $propertyName);
		if ($propertyReflection === null) {
			return $this;
		}
		$declaringClass = $propertyReflection->getDeclaringClass();
		if ($this->getClassReflection()->getName() !== $declaringClass->getName()) {
			return $this;
		}
		if (!$declaringClass->hasNativeProperty($propertyName)) {
			return $this;
		}

		$scope = $this->assignExpression(new PropertyInitializationExpr($propertyName), new MixedType(), new MixedType());

		$function = $scope->getFunction();
		if (
			$function instanceof MethodReflection
			&& strtolower($function->getName()) === '__clone'
			&& $scope->services->phpVersion->supportsReadonlyPropertyReinitializationOnClone()
		) {
			$scope = $scope->assignExpression(new CloneReinitializationExpr($propertyName), new MixedType(), new MixedType());
		}

		return $scope;
	}

	/**
	 * @param bool $keepPropertyFetches Keeps property fetches on the invalidated expression
	 *                                  (like '$this->foo') - for callees that never receive
	 *                                  the object, like static methods and static closures.
	 */
	public function invalidateExpression(Expr $expressionToInvalidate, bool $requireMoreCharacters = false, ?ClassReflection $invalidatingClass = null, bool $keepPropertyFetches = false): self
	{
		$exprStringToInvalidate = $this->getNodeKey($expressionToInvalidate);

		$result = ScopeOps::invalidateExpressionEntries(
			$this,
			$this->services->exprPrinter,
			$exprStringToInvalidate,
			$expressionToInvalidate,
			$requireMoreCharacters,
			$invalidatingClass,
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$keepPropertyFetches,
		);
		if ($result === null) {
			return $this;
		}

		/** @var static */
		return ScopeOps::scopeWith(
			$this,
			$result[0],
			$result[1],
			$result[2],
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			[],
			$this->inFirstLevelStatement,
			$this->afterExtractCall,
		);
	}

	/** @internal called by ScopeOps */
	public function isPrivatePropertyOfDifferentClass(Expr $expr, ClassReflection $invalidatingClass): bool
	{
		if ($expr instanceof Expr\StaticPropertyFetch || $expr instanceof PropertyFetch) {
			$propertyReflection = $this->services->propertyReflectionFinder->findPropertyReflectionFromNode($expr, $this);
			if ($propertyReflection === null) {
				return false;
			}
			if (!$propertyReflection->isPrivate()) {
				return false;
			}
			return $propertyReflection->getDeclaringClass()->getName() !== $invalidatingClass->getName();
		}

		return false;
	}

	private function invalidateMethodsOnExpression(Expr $expressionToInvalidate): self
	{
		$result = ScopeOps::invalidateMethodsOnExpression(
			$this->services->exprPrinter,
			$this->getNodeKey($expressionToInvalidate),
			$this->expressionTypes,
			$this->nativeExpressionTypes,
		);
		if ($result === null) {
			return $this;
		}

		/** @var static */
		return ScopeOps::scopeWith(
			$this,
			$result[0],
			$result[1],
			$this->conditionalExpressions,
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			[],
			$this->inFirstLevelStatement,
			$this->afterExtractCall,
		);
	}

	/**
	 * Certainty change for applySpecifiedTypes():
	 * it keeps the type already held for the expression instead of re-reading it
	 * via getType(). getType() only reports the type of Yes-certainty holders, so
	 * for a maybe-defined variable it broadens to the original type - which would
	 * overwrite a co-applied narrowing (e.g. isset's $a -> null in the else branch).
	 */
	private function setExpressionCertaintyKeepingType(Expr $expr, TrinaryLogic $certainty): self
	{
		$exprString = $this->getNodeKey($expr);
		if (!array_key_exists($exprString, $this->expressionTypes)) {
			throw new ShouldNotHappenException();
		}

		$exprType = $this->expressionTypes[$exprString]->getType();
		$nativeType = array_key_exists($exprString, $this->nativeExpressionTypes)
			? $this->nativeExpressionTypes[$exprString]->getType()
			: $exprType;

		return $this->specifyExpressionType(
			$expr,
			$exprType,
			$nativeType,
			$certainty,
		);
	}

	/**
	 * Returns true when the type is a large union with intersection
	 * members that carry HasOffsetValueType — a sign of combinatorial
	 * growth from successive array|object offset access patterns.
	 * Operating on such types is expensive and should be skipped.
	 */
	private function isComplexUnionType(Type $type): bool
	{
		if (!$type instanceof UnionType) {
			return false;
		}
		$types = $type->getTypes();
		if (count($types) <= self::COMPLEX_UNION_TYPE_MEMBER_LIMIT) {
			return false;
		}
		foreach ($types as $member) {
			if (!$member instanceof IntersectionType) {
				continue;
			}
			foreach ($member->getTypes() as $innerType) {
				if ($innerType instanceof HasOffsetValueType) {
					return true;
				}
			}
		}
		return false;
	}

	public function addTypeToExpression(Expr $expr, Type $type): self
	{
		$originalExprType = $this->getScopeStateType($expr);
		if ($this->isComplexUnionType($originalExprType)) {
			return $this;
		}

		$nativeType = $this->getScopeStateNativeType($expr);

		if ($originalExprType->equals($nativeType)) {
			$newType = TypeCombinator::intersect($type, $originalExprType);
			return $this->specifyExpressionType($expr, $newType, $newType, TrinaryLogic::createYes());
		}

		return $this->specifyExpressionType(
			$expr,
			TypeCombinator::intersect($type, $originalExprType),
			TypeCombinator::intersect($type, $nativeType),
			TrinaryLogic::createYes(),
		);
	}

	public function removeTypeFromExpression(Expr $expr, Type $typeToRemove): self
	{
		if ($typeToRemove instanceof NeverType) {
			return $this;
		}

		$exprType = $this->getScopeStateType($expr);
		if ($exprType instanceof NeverType) {
			return $this;
		}

		if ($this->isComplexUnionType($exprType)) {
			return $this;
		}

		return $this->specifyExpressionType(
			$expr,
			TypeCombinator::remove($exprType, $typeToRemove),
			TypeCombinator::remove($this->getScopeStateNativeType($expr), $typeToRemove),
			TrinaryLogic::createYes(),
		);
	}

	/**
	 * @api
	 */
	public function filterByTruthyValue(Expr $expr): self
	{
		$specifiedTypes = $this->services->typeSpecifier->specifyTypesInCondition($this, $expr, TypeSpecifierContext::createTruthy());
		if ($specifiedTypes->isEquality() && $this->getType($expr)->isBoolean()->yes()) {
			$specifiedTypes = $specifiedTypes->unionWith(
				$this->services->typeSpecifier->create($expr, new ConstantBooleanType(true), TypeSpecifierContext::createTrue(), $this),
			);
		}

		return $this->applySpecifiedTypes($specifiedTypes);
	}

	/**
	 * @api
	 */
	public function filterByFalseyValue(Expr $expr): self
	{
		$specifiedTypes = $this->services->typeSpecifier->specifyTypesInCondition($this, $expr, TypeSpecifierContext::createFalsey());
		if ($specifiedTypes->isEquality() && $this->getType($expr)->isBoolean()->yes()) {
			$specifiedTypes = $specifiedTypes->unionWith(
				$this->services->typeSpecifier->create($expr, new ConstantBooleanType(false), TypeSpecifierContext::createTrue(), $this),
			);
		}

		return $this->applySpecifiedTypes($specifiedTypes);
	}

	/**
	 * Applies computed narrowing to this scope.
	 *
	 * The types inside SpecifiedTypes were already computed from ExpressionResults
	 * by the specifyTypesCallback of an ExprHandler. This method must never call
	 * Scope::getType() - it only combines the given types with already-tracked
	 * expression type holders.
	 *
	 * @return static
	 */
	public function applySpecifiedTypes(SpecifiedTypes $specifiedTypes): self
	{
		// deferred augments see this scope's pre-application state - the
		// application point of the narrowing; their entries join this batch
		$pendingAugments = $specifiedTypes->getDeferredAugments();
		while ($pendingAugments !== []) {
			$augment = array_shift($pendingAugments);
			$augmentTypes = $augment->evaluate($this);
			if ($augmentTypes === null) {
				continue;
			}

			foreach ($augmentTypes->getDeferredAugments() as $nestedAugment) {
				$pendingAugments[] = $nestedAugment;
			}
			$specifiedTypes = $specifiedTypes->unionWith($augmentTypes);
		}

		$typeSpecifications = [];
		foreach ($specifiedTypes->getSureTypes() as $exprString => [$expr, $type]) {
			if ($expr instanceof Node\Scalar || $expr instanceof Array_ || $expr instanceof Expr\UnaryMinus && $expr->expr instanceof Node\Scalar) {
				continue;
			}
			$typeSpecifications[] = [
				'sure' => true,
				'exprString' => (string) $exprString,
				'expr' => $expr,
				'type' => $type,
			];
		}
		foreach ($specifiedTypes->getSureNotTypes() as $exprString => [$expr, $type]) {
			if ($expr instanceof Node\Scalar || $expr instanceof Array_ || $expr instanceof Expr\UnaryMinus && $expr->expr instanceof Node\Scalar) {
				continue;
			}
			$typeSpecifications[] = [
				'sure' => false,
				'exprString' => (string) $exprString,
				'expr' => $expr,
				'type' => $type,
			];
		}
		foreach ($specifiedTypes->getAlternativeTypes() as $exprString => [$expr, $terms]) {
			if ($expr instanceof Node\Scalar || $expr instanceof Array_ || $expr instanceof Expr\UnaryMinus && $expr->expr instanceof Node\Scalar) {
				continue;
			}
			$typeSpecifications[] = [
				'sure' => true,
				'exprString' => (string) $exprString,
				'expr' => $expr,
				'terms' => $terms,
			];
		}

		usort($typeSpecifications, static function (array $a, array $b): int {
			$length = strlen($a['exprString']) - strlen($b['exprString']);
			if ($length !== 0) {
				return $length;
			}

			return $b['sure'] - $a['sure']; // @phpstan-ignore minus.leftNonNumeric, minus.rightNonNumeric
		});

		$scope = $this;
		// one unpublished working copy takes all in-place specifications of the
		// batch; operations that go through other scope derivations publish it
		// and a fresh copy opens on the next specification
		$scopeIsWorkingCopy = false;
		$specifiedExpressions = [];
		foreach ($typeSpecifications as $typeSpecification) {
			$expr = $typeSpecification['expr'];
			$exprString = $typeSpecification['exprString'];

			if ($expr instanceof IssetExpr) {
				$issetExpr = $expr;
				$expr = $issetExpr->getExpr();

				if ($typeSpecification['sure']) {
					$innerExprString = $scope->getNodeKey($expr);
					$scope = $scope->setExpressionCertaintyKeepingType(
						$expr,
						TrinaryLogic::createMaybe(),
					);
					$specifiedExpressions[$innerExprString] = ExpressionTypeHolder::createMaybe(
						$expr,
						$scope->expressionTypes[$innerExprString]->getType(),
					);
				} else {
					$innerExprString = $scope->getNodeKey($expr);
					// Holders conditioned on this expression being undefined (a
					// certainty-No condition) wait for exactly the specification
					// applied here, but unsetExpression()'s invalidation would drop
					// them before the conditional-expressions matcher below could
					// fire them - carve them out and re-add them afterwards.
					$rescuedHolders = [];
					foreach ($scope->conditionalExpressions as $targetExprString => $targetHolders) {
						foreach ($targetHolders as $holderKey => $conditionalHolder) {
							$conditionHolder = $conditionalHolder->getConditionExpressionTypeHolders()[$innerExprString] ?? null;
							if ($conditionHolder === null || !$conditionHolder->getCertainty()->no()) {
								continue;
							}
							$rescuedHolders[$targetExprString][$holderKey] = $conditionalHolder;
						}
					}
					$scope = $scope->unsetExpression($expr);
					foreach ($rescuedHolders as $targetExprString => $targetHolders) {
						$scope = $scope->addConditionalExpressions((string) $targetExprString, $targetHolders); // @phpstan-ignore cast.useless
					}
					$specifiedExpressions[$innerExprString] = new ExpressionTypeHolder($expr, new ErrorType(), TrinaryLogic::createNo());
				}
				$scopeIsWorkingCopy = false;

				continue;
			}

			if (
				!$typeSpecification['sure']
				&& $expr instanceof Variable && is_string($expr->name)
				&& $scope->hasVariableType($expr->name)->no()
			) {
				// removing type from a certainly-undefined variable cannot make
				// it defined; a sure specification (e.g. is_string($a)) still can -
				// the condition can only hold for a defined variable
				continue;
			}

			// only Yes-certainty holders hold the current type of the expression -
			// a Maybe-certainty holder holds the when-defined type (e.g. after
			// merging a branch where the expression was never assigned), which
			// the certainty-aware Scope::getType() of the old world never returned
			$trackedType = null;
			$trackedNativeType = null;
			if (
				array_key_exists($exprString, $scope->expressionTypes)
				&& $scope->expressionTypes[$exprString]->getCertainty()->yes()
			) {
				$trackedType = $scope->expressionTypes[$exprString]->getType();
			}
			if (
				array_key_exists($exprString, $scope->nativeExpressionTypes)
				&& $scope->nativeExpressionTypes[$exprString]->getCertainty()->yes()
			) {
				$trackedNativeType = $scope->nativeExpressionTypes[$exprString]->getType();
			}
			if ($trackedType === null) {
				$currentTypes = $scope->getCurrentTypesOfSpecifiedExpr($expr);
				if ($currentTypes !== null) {
					if ($scope->isComplexUnionType($currentTypes[0])) {
						continue;
					}

					$trackedType = $currentTypes[0];
					$trackedNativeType ??= $currentTypes[1];
				}
			} elseif (!$specifiedTypes->shouldOverwrite() && $scope->isComplexUnionType($trackedType)) {
				// mirrors addTypeToExpression()/removeTypeFromExpression(): narrowing
				// a combinatorially-grown offset union doubles it with every isset()-
				// style check and gets skipped (overwrites assign, they never narrow)
				continue;
			}

			if (isset($typeSpecification['terms'])) {
				// an alternative-form entry: the union over its terms of
				// `(sure ?? current) minus subtract`, evaluated here at the
				// application point - the deferred descendant of the old
				// SpecifiedTypes::normalize()
				$evaluate = static function (?Type $current) use ($typeSpecification): ?Type {
					$parts = [];
					foreach ($typeSpecification['terms'] as [$sure, $subtract]) {
						$base = $sure ?? $current;
						if ($base === null) {
							return null;
						}
						$parts[] = $subtract !== null ? TypeCombinator::remove($base, $subtract) : $base;
					}

					return TypeCombinator::union(...$parts);
				};
				$evaluated = $evaluate($trackedType);
				if ($evaluated === null) {
					// a current-type-dependent term with no known current type -
					// nothing sound to specify (mirrors the sure-not behaviour)
					continue;
				}
				$evaluatedNative = $evaluate($trackedNativeType ?? $trackedType) ?? $evaluated;

				$newType = $trackedType !== null ? TypeCombinator::intersect($evaluated, $trackedType) : $evaluated;
				$newNativeType = $trackedNativeType !== null ? TypeCombinator::intersect($evaluatedNative, $trackedNativeType) : $evaluatedNative;
				if (!$this->isSpecifyExpressionTypeNoop($expr, $newType)) {
					if (!$scopeIsWorkingCopy) {
						$scope = $scope->openSpecificationScope();
						$scopeIsWorkingCopy = true;
					}
					$scope->specifyExpressionTypeInPlace($expr, $newType, $newNativeType, TrinaryLogic::createYes());
				}

				$holderType = array_key_exists($exprString, $scope->expressionTypes)
					? $scope->expressionTypes[$exprString]->getType()
					: $newType;
				$specifiedExpressions[$exprString] = ExpressionTypeHolder::createYes($expr, $holderType);
				continue;
			}

			$type = $typeSpecification['type'];
			if ($typeSpecification['sure']) {
				if ($specifiedTypes->shouldOverwrite()) {
					$scope = $scope->overwriteExpression($expr, $type, $type);
					$scopeIsWorkingCopy = false;
				} else {
					$newType = $trackedType !== null ? TypeCombinator::intersect($type, $trackedType) : $type;
					$newNativeType = $trackedNativeType !== null ? TypeCombinator::intersect($type, $trackedNativeType) : $type;
					if (!$this->isSpecifyExpressionTypeNoop($expr, $newType)) {
						if (!$scopeIsWorkingCopy) {
							$scope = $scope->openSpecificationScope();
							$scopeIsWorkingCopy = true;
						}
						$scope->specifyExpressionTypeInPlace($expr, $newType, $newNativeType, TrinaryLogic::createYes());
					}
				}
			} else {
				if ($type instanceof NeverType || $trackedType instanceof NeverType) {
					continue;
				}
				$newType = $trackedType !== null ? TypeCombinator::remove($trackedType, $type) : null;
				if ($newType === null) {
					// the expression is not tracked - there is nothing to subtract from
					continue;
				}
				$newNativeType = $trackedNativeType !== null ? TypeCombinator::remove($trackedNativeType, $type) : $newType;
				if (!$this->isSpecifyExpressionTypeNoop($expr, $newType)) {
					if (!$scopeIsWorkingCopy) {
						$scope = $scope->openSpecificationScope();
						$scopeIsWorkingCopy = true;
					}
					$scope->specifyExpressionTypeInPlace($expr, $newType, $newNativeType, TrinaryLogic::createYes());
				}
			}

			$holderType = array_key_exists($exprString, $scope->expressionTypes)
				? $scope->expressionTypes[$exprString]->getType()
				: $type;
			$specifiedExpressions[$exprString] = ExpressionTypeHolder::createYes($expr, $holderType);
		}

		$scope = $scope->processConditionalExpressionsAfterSpecifying($specifiedExpressions);

		$newConditionalExpressionHolders = $specifiedTypes->getNewConditionalExpressionHolders();
		foreach ($specifiedTypes->getConditionalExpressionHolderRecipes() as $recipe) {
			// the recipes' state-dependent math runs here, against this scope's
			// pre-application state - the application point of the narrowing
			foreach ($recipe->evaluate($this) as $exprString => $recipeHolders) {
				foreach ($recipeHolders as $key => $holder) {
					$newConditionalExpressionHolders[$exprString][$key] = $holder;
				}
			}
		}

		/** @var static */
		return $scope->scopeFactory->create(
			$scope->context,
			$scope->isDeclareStrictTypes(),
			$scope->getFunction(),
			$scope->getNamespace(),
			$scope->expressionTypes,
			$scope->nativeExpressionTypes,
			$this->mergeConditionalExpressions($newConditionalExpressionHolders, $scope->conditionalExpressions),
			$scope->inClosureBindScopeClasses,
			$scope->anonymousFunctionReflection,
			$scope->inFirstLevelStatement,
			$scope->currentlyAssignedExpressions,
			$scope->currentlyAllowedUndefinedExpressions,
			$scope->inFunctionCallsStack,
			$scope->afterExtractCall,
			$scope->parentScope,
			$scope->nativeTypesPromoted,
			$scope->templateArgumentFrame,
			$scope->templateArgumentConstraints,
		);
	}

	/**
	 * Matches already-registered conditional expressions against the just-specified
	 * expression type holders and applies the matching consequences.
	 *
	 * Mutates and returns $this - only to be called on an intermediate scope
	 * that is about to be rebuilt through the scope factory.
	 *
	 * @param array<string, ExpressionTypeHolder> $specifiedExpressions
	 */
	private function processConditionalExpressionsAfterSpecifying(array $specifiedExpressions): self
	{
		$scope = $this;
		[$conditions] = ScopeOps::matchConditionalExpressions($scope->conditionalExpressions, $specifiedExpressions);

		foreach ($conditions as $conditionalExprString => $expressions) {
			$certainty = TrinaryLogic::lazyExtremeIdentity($expressions, static fn (ConditionalExpressionHolder $holder) => $holder->getTypeHolder()->getCertainty());
			if ($certainty->no()) {
				unset($scope->expressionTypes[$conditionalExprString]);
			} else {
				if (array_key_exists($conditionalExprString, $scope->expressionTypes)) {
					$type = $expressions[0]->getTypeHolder()->getType();
					for ($i = 1, $count = count($expressions); $i < $count; $i++) {
						$type = TypeCombinator::intersect($type, $expressions[$i]->getTypeHolder()->getType());
					}

					$scope->expressionTypes[$conditionalExprString] = new ExpressionTypeHolder(
						$scope->expressionTypes[$conditionalExprString]->getExpr(),
						TypeCombinator::intersect($scope->expressionTypes[$conditionalExprString]->getType(), $type),
						TrinaryLogic::maxMin($scope->expressionTypes[$conditionalExprString]->getCertainty(), $certainty),
					);
				} else {
					$scope->expressionTypes[$conditionalExprString] = $expressions[0]->getTypeHolder();
				}
			}
		}

		return $scope;
	}

	/**
	 * @return array<string, ConditionalExpressionHolder[]>
	 */
	public function getConditionalExpressions(): array
	{
		return $this->conditionalExpressions;
	}

	/**
	 * @param ConditionalExpressionHolder[] $conditionalExpressionHolders
	 */
	public function addConditionalExpressions(string $exprString, array $conditionalExpressionHolders): self
	{
		$conditionalExpressions = $this->conditionalExpressions;
		// Merge rather than overwrite: multiple independent holders can target the same
		// expression (e.g. `$xIsA = $x instanceof A && $y instanceof A` stores a holder
		// for `$x` keyed on `$xIsA`; later `$yIsA = $y instanceof A && $x instanceof A`
		// stores another holder for the same target `$x` keyed on `$yIsA`). Replacing
		// the existing entry here would throw away the earlier binding, breaking
		// narrowing inside later `if ($xIsA) { … }` inside `if ($xIsA || $yIsA)`.
		// Holder keys (`getKey()`) disambiguate identical entries so we still dedupe.
		$existing = $conditionalExpressions[$exprString] ?? [];
		foreach ($conditionalExpressionHolders as $holder) {
			$existing[$holder->getKey()] = $holder;
		}
		$conditionalExpressions[$exprString] = $existing;

		/** @var static */
		return ScopeOps::scopeWith(
			$this,
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$conditionalExpressions,
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			$this->inFirstLevelStatement,
			$this->afterExtractCall,
		);
	}

	public function exitFirstLevelStatements(): self
	{
		if (!$this->inFirstLevelStatement) {
			return $this;
		}

		if ($this->scopeOutOfFirstLevelStatement !== null) {
			return $this->scopeOutOfFirstLevelStatement;
		}

		/** @var static $scope */
		$scope = ScopeOps::scopeWith(
			$this,
			$this->expressionTypes,
			$this->nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->currentlyAssignedExpressions,
			$this->currentlyAllowedUndefinedExpressions,
			$this->inFunctionCallsStack,
			false,
			$this->afterExtractCall,
		);
		$scope->resolvedTypes = $this->resolvedTypes;
		$this->scopeOutOfFirstLevelStatement = $scope;

		return $scope;
	}

	/** @api */
	public function isInFirstLevelStatement(): bool
	{
		return $this->inFirstLevelStatement;
	}

	public function mergeWith(?self $otherScope, bool $preserveVacuousConditionals = false): self
	{
		$merged = $this->mergeWithVariableState($otherScope, $preserveVacuousConditionals)->addTemplateArgumentConstraints($otherScope !== null ? $otherScope->getTemplateArgumentConstraints() : null);
		if (
			$otherScope === null
			|| $merged->templateArgumentConstraints === null
			|| $merged->templateArgumentFrame === null
			|| !$merged->templateArgumentFrame->isObservingClosures()
		) {
			return $merged;
		}

		return $merged->addTemplateArgumentConstraints($merged->collectAbsorbedClosures($this, $otherScope));
	}

	/**
	 * The closures a variable held on one side of a merge and the merged
	 * variable lost - see ClosureSignatureInference::collectAbsorbed().
	 */
	private function collectAbsorbedClosures(self $ours, self $theirs): ?TemplateArgumentConstraints
	{
		$constraints = null;
		foreach ($this->expressionTypes as $key => $holder) {
			foreach ([$ours->expressionTypes[$key] ?? null, $theirs->expressionTypes[$key] ?? null] as $sideHolder) {
				if ($sideHolder === null || $sideHolder === $holder || $sideHolder->getType() === $holder->getType()) {
					continue;
				}
				$absorbed = ClosureSignatureInference::collectAbsorbed($sideHolder->getType(), $holder->getType());
				if ($absorbed->isEmpty()) {
					continue;
				}
				$constraints = $constraints === null ? $absorbed : $constraints->merge($absorbed);
			}
		}

		return $constraints;
	}

	private function mergeWithVariableState(?self $otherScope, bool $preserveVacuousConditionals = false): self
	{
		if ($otherScope === null || $this === $otherScope) {
			return $this;
		}
		$ourExpressionTypes = $this->expressionTypes;
		$theirExpressionTypes = $otherScope->expressionTypes;

		$differingExpressionKeys = [];
		$mergedExpressionTypes = ScopeOps::mergeVariableHolders($ourExpressionTypes, $theirExpressionTypes, $differingExpressionKeys);
		$differingExpressionKeys = $this->withoutPreciseClassConstantFetches($differingExpressionKeys, $ourExpressionTypes, $theirExpressionTypes);
		$conditionalExpressions = ScopeOps::intersectConditionalExpressions($this->conditionalExpressions, $otherScope->conditionalExpressions);
		if ($preserveVacuousConditionals) {
			$conditionalExpressions = $this->preserveVacuousConditionalExpressions(
				$conditionalExpressions,
				$this->conditionalExpressions,
				$theirExpressionTypes,
			);
			$conditionalExpressions = $this->preserveVacuousConditionalExpressions(
				$conditionalExpressions,
				$otherScope->conditionalExpressions,
				$ourExpressionTypes,
			);
		}
		$conditionalExpressions = $this->mergeSameGuardConditionalExpressions(
			$conditionalExpressions,
			$this->conditionalExpressions,
			$otherScope->conditionalExpressions,
		);
		$conditionalExpressions = ScopeOps::createConditionalExpressions(
			$conditionalExpressions,
			$ourExpressionTypes,
			$theirExpressionTypes,
			$mergedExpressionTypes,
			$differingExpressionKeys,
		);
		$conditionalExpressions = ScopeOps::createConditionalExpressions(
			$conditionalExpressions,
			$theirExpressionTypes,
			$ourExpressionTypes,
			$mergedExpressionTypes,
			$differingExpressionKeys,
		);

		[$mergedExpressionTypes, $mergedNativeTypes] = ScopeOps::finishMerge(
			$mergedExpressionTypes,
			$ourExpressionTypes,
			$theirExpressionTypes,
			$this->nativeExpressionTypes,
			$otherScope->nativeExpressionTypes,
		);

		/** @var static */
		return ScopeOps::scopeWith(
			$this,
			$mergedExpressionTypes,
			$mergedNativeTypes,
			$conditionalExpressions,
			[],
			[],
			[],
			$this->inFirstLevelStatement,
			$this->afterExtractCall && $otherScope->afterExtractCall,
		);
	}

	/**
	 * Drops the keys of class-constant fetches that resolve to their declared value.
	 *
	 * A conditional expression records "when the guard holds, this expression had
	 * that type in the branch the guard selects". Such a record can only ever pay
	 * off when the expression resolves to something less precise on its own - and
	 * a class-constant fetch with a statically known class resolves to the exact
	 * declared value, unless the constant is configured as dynamic. So the record
	 * is bookkeeping that can never narrow anything, and an expensive one: creating
	 * it compares the guard against every member of the (potentially very wide)
	 * merged guard type.
	 *
	 * @param array<string, true> $differingExpressionKeys
	 * @param array<string, ExpressionTypeHolder> $ourExpressionTypes
	 * @param array<string, ExpressionTypeHolder> $theirExpressionTypes
	 * @return array<string, true>
	 */
	private function withoutPreciseClassConstantFetches(
		array $differingExpressionKeys,
		array $ourExpressionTypes,
		array $theirExpressionTypes,
	): array
	{
		foreach (array_keys($differingExpressionKeys) as $exprString) {
			$holder = $ourExpressionTypes[$exprString] ?? $theirExpressionTypes[$exprString] ?? null;
			if ($holder === null) {
				continue;
			}

			$expr = $holder->getExpr();
			if (
				!$expr instanceof ClassConstFetch
				|| !$expr->class instanceof Name
				|| !$expr->name instanceof Identifier
			) {
				continue;
			}

			// static::CONST is late-bound, so which class - and therefore which
			// declared value - it resolves to is not known here.
			if ($expr->class->toLowerString() === 'static') {
				continue;
			}

			if ($this->services->constantResolver->isDynamicClassConstant($this->resolveName($expr->class), $expr->name->toString())) {
				continue;
			}

			unset($differingExpressionKeys[$exprString]);
		}

		return $differingExpressionKeys;
	}

	/**
	 * Rescues one-sided conditional holders across an if-merge.
	 *
	 * A holder missing from the intersection survives when either some guard's
	 * recorded type is impossible in the other branch (the holder is vacuously
	 * true there), or the other branch's flat state for the holder's target
	 * already satisfies the holder's consequent (subtype with at-least-as-strong
	 * certainty) - the consequent then holds on both paths under the guard.
	 *
	 * @param array<string, ConditionalExpressionHolder[]> $currentConditionalExpressions
	 * @param array<string, ConditionalExpressionHolder[]> $sourceConditionalExpressions
	 * @param array<string, ExpressionTypeHolder> $otherExpressionTypes
	 * @return array<string, ConditionalExpressionHolder[]>
	 */
	private function preserveVacuousConditionalExpressions(
		array $currentConditionalExpressions,
		array $sourceConditionalExpressions,
		array $otherExpressionTypes,
	): array
	{
		foreach ($sourceConditionalExpressions as $exprString => $holders) {
			foreach ($holders as $key => $holder) {
				if (isset($currentConditionalExpressions[$exprString][$key])) {
					continue;
				}

				$typeHolder = $holder->getTypeHolder();
				if ($typeHolder->getCertainty()->no() && !$typeHolder->getExpr() instanceof Variable) {
					continue;
				}

				foreach ($holder->getConditionExpressionTypeHolders() as $guardExprString => $guardTypeHolder) {
					if (!array_key_exists($guardExprString, $otherExpressionTypes)) {
						continue;
					}

					$otherType = $otherExpressionTypes[$guardExprString]->getType();
					$guardType = $guardTypeHolder->getType();

					if ($otherType->isSuperTypeOf($guardType)->no()) {
						$currentConditionalExpressions[$exprString][$key] = $holder;
						continue 2;
					}
				}

				if ($typeHolder->getCertainty()->no() || !array_key_exists($exprString, $otherExpressionTypes)) {
					continue;
				}

				$otherTargetHolder = $otherExpressionTypes[$exprString];
				$otherTargetCertainty = $otherTargetHolder->getCertainty();
				if (!$otherTargetCertainty->yes() && !$otherTargetCertainty->equals($typeHolder->getCertainty())) {
					continue;
				}

				// An unresolved expression (e.g. an access to an undefined property) is held
				// as ErrorType. ErrorType is a subtype of everything, so a consequent or an
				// other-branch state of ErrorType would look "already satisfied" and preserve
				// a holder that tracks the expression and hides the underlying error. Such a
				// holder carries no real type relationship, so skip it.
				if ($typeHolder->getType() instanceof ErrorType || $otherTargetHolder->getType() instanceof ErrorType) {
					continue;
				}

				if (!$typeHolder->getType()->isSuperTypeOf($otherTargetHolder->getType())->yes()) {
					continue;
				}

				$currentConditionalExpressions[$exprString][$key] = $holder;
			}
		}

		return $currentConditionalExpressions;
	}

	/**
	 * Merges one-sided holders that share a target and an identical guard set:
	 * whichever branch a merged path came from, the guard matching later implies
	 * one of the recorded consequents, so the union of the consequent types
	 * (under their shared certainty) holds on every merged path.
	 *
	 * @param array<string, ConditionalExpressionHolder[]> $currentConditionalExpressions
	 * @param array<string, ConditionalExpressionHolder[]> $ourConditionalExpressions
	 * @param array<string, ConditionalExpressionHolder[]> $theirConditionalExpressions
	 * @return array<string, ConditionalExpressionHolder[]>
	 */
	private function mergeSameGuardConditionalExpressions(
		array $currentConditionalExpressions,
		array $ourConditionalExpressions,
		array $theirConditionalExpressions,
	): array
	{
		foreach ($ourConditionalExpressions as $exprString => $ourHolders) {
			if (!array_key_exists($exprString, $theirConditionalExpressions)) {
				continue;
			}

			$theirHolders = $theirConditionalExpressions[$exprString];
			foreach ($ourHolders as $ourKey => $ourHolder) {
				if (isset($currentConditionalExpressions[$exprString][$ourKey])) {
					continue;
				}

				$ourTypeHolder = $ourHolder->getTypeHolder();
				if ($ourTypeHolder->getCertainty()->no()) {
					continue;
				}

				foreach ($theirHolders as $theirKey => $theirHolder) {
					if (isset($currentConditionalExpressions[$exprString][$theirKey])) {
						continue;
					}

					$theirTypeHolder = $theirHolder->getTypeHolder();
					if (!$theirTypeHolder->getCertainty()->equals($ourTypeHolder->getCertainty())) {
						continue;
					}

					$ourGuards = $ourHolder->getConditionExpressionTypeHolders();
					$theirGuards = $theirHolder->getConditionExpressionTypeHolders();
					if (count($ourGuards) !== count($theirGuards)) {
						continue;
					}

					foreach ($ourGuards as $guardExprString => $ourGuardHolder) {
						if (
							!array_key_exists($guardExprString, $theirGuards)
							|| !$ourGuardHolder->equals($theirGuards[$guardExprString])
						) {
							continue 2;
						}
					}

					$unionHolder = new ConditionalExpressionHolder(
						$ourGuards,
						new ExpressionTypeHolder(
							$ourTypeHolder->getExpr(),
							TypeCombinator::union($ourTypeHolder->getType(), $theirTypeHolder->getType()),
							$ourTypeHolder->getCertainty(),
						),
					);
					$currentConditionalExpressions[$exprString][$unionHolder->getKey()] = $unionHolder;
				}
			}
		}

		return $currentConditionalExpressions;
	}

	/**
	 * @param array<string, ConditionalExpressionHolder[]> $newConditionalExpressions
	 * @param array<string, ConditionalExpressionHolder[]> $existingConditionalExpressions
	 * @return array<string, ConditionalExpressionHolder[]>
	 */
	private function mergeConditionalExpressions(array $newConditionalExpressions, array $existingConditionalExpressions): array
	{
		$result = $existingConditionalExpressions;
		foreach ($newConditionalExpressions as $exprString => $holders) {
			if (!array_key_exists($exprString, $result)) {
				$result[$exprString] = $holders;
			} else {
				$result[$exprString] = array_merge($result[$exprString], $holders);
			}
		}

		return $result;
	}

	public function mergeInitializedProperties(self $calledMethodScope): self
	{
		$scope = $this;
		foreach ($calledMethodScope->expressionTypes as $exprString => $typeHolder) {
			$exprString = (string) $exprString;
			if (!str_starts_with($exprString, '__phpstanPropertyInitialization(')) {
				continue;
			}
			$propertyName = substr($exprString, strlen('__phpstanPropertyInitialization('), -1);
			$propertyExpr = new PropertyInitializationExpr($propertyName);
			if (!array_key_exists($exprString, $scope->expressionTypes)) {
				$scope = $scope->assignExpression($propertyExpr, new MixedType(), new MixedType());
				$scope->expressionTypes[$exprString] = $typeHolder;
				continue;
			}

			$certainty = $scope->expressionTypes[$exprString]->getCertainty();
			$scope = $scope->assignExpression($propertyExpr, new MixedType(), new MixedType());
			$scope->expressionTypes[$exprString] = new ExpressionTypeHolder(
				$typeHolder->getExpr(),
				$typeHolder->getType(),
				$typeHolder->getCertainty()->or($certainty),
			);
		}

		return $scope;
	}

	public function processFinallyScope(self $finallyScope, self $originalFinallyScope): self
	{
		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$this->processFinallyScopeVariableTypeHolders(
				$this->expressionTypes,
				$finallyScope->expressionTypes,
				$originalFinallyScope->expressionTypes,
			),
			$this->processFinallyScopeVariableTypeHolders(
				$this->nativeExpressionTypes,
				$finallyScope->nativeExpressionTypes,
				$originalFinallyScope->nativeExpressionTypes,
			),
			ScopeOps::intersectConditionalExpressions($this->conditionalExpressions, $finallyScope->conditionalExpressions),
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			[],
			[],
			[],
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * @param array<string, ExpressionTypeHolder> $ourVariableTypeHolders
	 * @param array<string, ExpressionTypeHolder> $finallyVariableTypeHolders
	 * @param array<string, ExpressionTypeHolder> $originalVariableTypeHolders
	 * @return array<string, ExpressionTypeHolder>
	 */
	private function processFinallyScopeVariableTypeHolders(
		array $ourVariableTypeHolders,
		array $finallyVariableTypeHolders,
		array $originalVariableTypeHolders,
	): array
	{
		foreach ($finallyVariableTypeHolders as $exprString => $variableTypeHolder) {
			if (
				isset($originalVariableTypeHolders[$exprString])
				&& !$originalVariableTypeHolders[$exprString]->equalTypes($variableTypeHolder)
			) {
				$ourVariableTypeHolders[$exprString] = $variableTypeHolder;
				continue;
			}

			if (isset($originalVariableTypeHolders[$exprString])) {
				continue;
			}

			$ourVariableTypeHolders[$exprString] = $variableTypeHolder;
		}

		return $ourVariableTypeHolders;
	}

	/**
	 * @param Node\ClosureUse[] $byRefUses
	 */
	public function processClosureScope(
		self $closureScope,
		?self $prevScope,
		array $byRefUses,
	): self
	{
		$nativeExpressionTypes = $this->nativeExpressionTypes;
		$expressionTypes = $this->expressionTypes;
		if (count($byRefUses) === 0) {
			return $this;
		}

		foreach ($byRefUses as $use) {
			if (!is_string($use->var->name)) {
				throw new ShouldNotHappenException();
			}

			$variableName = $use->var->name;
			$variableExprString = '$' . $variableName;

			if (!$closureScope->hasVariableType($variableName)->yes()) {
				$holder = ExpressionTypeHolder::createYes($use->var, new NullType());
				$expressionTypes[$variableExprString] = $holder;
				$nativeExpressionTypes[$variableExprString] = $holder;
				continue;
			}

			$variableType = $closureScope->getVariableType($variableName);

			if ($prevScope !== null) {
				$prevVariableType = $prevScope->getVariableType($variableName);
				if (!$variableType->equals($prevVariableType)) {
					$variableType = TypeCombinator::union($variableType, $prevVariableType);
					$variableType = $this->generalizeType($variableType, $prevVariableType, 0);
				}
			}

			$holder = ExpressionTypeHolder::createYes($use->var, $variableType);
			$expressionTypes[$variableExprString] = $holder;
			$nativeExpressionTypes[$variableExprString] = $holder;
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeExpressionTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			[],
			[],
			$this->inFunctionCallsStack,
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	public function processAlwaysIterableForeachScopeWithoutPollute(self $finalScope): self
	{
		$expressionTypes = $this->expressionTypes;
		foreach ($finalScope->expressionTypes as $variableExprString => $variableTypeHolder) {
			if (!isset($expressionTypes[$variableExprString])) {
				$expressionTypes[$variableExprString] = ExpressionTypeHolder::createMaybe($variableTypeHolder->getExpr(), $variableTypeHolder->getType());
				continue;
			}

			$expressionTypes[$variableExprString] = new ExpressionTypeHolder(
				$variableTypeHolder->getExpr(),
				$variableTypeHolder->getType(),
				$variableTypeHolder->getCertainty()->and($expressionTypes[$variableExprString]->getCertainty()),
			);
		}
		$nativeTypes = $this->nativeExpressionTypes;
		foreach ($finalScope->nativeExpressionTypes as $variableExprString => $variableTypeHolder) {
			if (!isset($nativeTypes[$variableExprString])) {
				$nativeTypes[$variableExprString] = ExpressionTypeHolder::createMaybe($variableTypeHolder->getExpr(), $variableTypeHolder->getType());
				continue;
			}

			$nativeTypes[$variableExprString] = new ExpressionTypeHolder(
				$variableTypeHolder->getExpr(),
				$variableTypeHolder->getType(),
				$variableTypeHolder->getCertainty()->and($nativeTypes[$variableExprString]->getCertainty()),
			);
		}

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$expressionTypes,
			$nativeTypes,
			ScopeOps::intersectConditionalExpressions($this->conditionalExpressions, $finalScope->conditionalExpressions),
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			[],
			[],
			[],
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * @param array<string, true>|null $writableVariableNames variables the loop can write, null when unknown
	 */
	public function generalizeWith(self $otherScope, ?array $writableVariableNames = null): self
	{
		return $this->generalizeWithVariableState($otherScope, $writableVariableNames)->addTemplateArgumentConstraints($otherScope->getTemplateArgumentConstraints());
	}

	/**
	 * @param array<string, true>|null $writableVariableNames
	 */
	private function generalizeWithVariableState(self $otherScope, ?array $writableVariableNames): self
	{
		if ($writableVariableNames !== null) {
			// a reference created before the loop lets the loop write a variable it does not name
			foreach ([$this->expressionTypes, $otherScope->expressionTypes] as $expressionTypes) {
				foreach ($expressionTypes as $expressionTypeHolder) {
					$intertwinedExpr = $expressionTypeHolder->getExpr();
					if (!$intertwinedExpr instanceof IntertwinedVariableByReferenceWithExpr) {
						continue;
					}
					$writableVariableNames[$intertwinedExpr->getVariableName()] = true;
					foreach ([$intertwinedExpr->getExpr(), $intertwinedExpr->getAssignedExpr()] as $aliasedExpr) {
						$aliasedVariableName = ScopeOps::getIntertwinedRefRootVariableName($aliasedExpr);
						if ($aliasedVariableName === null) {
							continue;
						}
						$writableVariableNames[$aliasedVariableName] = true;
					}
				}
			}
		}
		$variableTypeHolders = $this->generalizeVariableTypeHolders(
			$this->expressionTypes,
			$otherScope->expressionTypes,
			$writableVariableNames,
		);
		$nativeTypes = $this->generalizeVariableTypeHolders(
			$this->nativeExpressionTypes,
			$otherScope->nativeExpressionTypes,
			$writableVariableNames,
		);

		return $this->scopeFactory->create(
			$this->context,
			$this->isDeclareStrictTypes(),
			$this->getFunction(),
			$this->getNamespace(),
			$variableTypeHolders,
			$nativeTypes,
			$this->conditionalExpressions,
			$this->inClosureBindScopeClasses,
			$this->anonymousFunctionReflection,
			$this->inFirstLevelStatement,
			[],
			[],
			[],
			$this->afterExtractCall,
			$this->parentScope,
			$this->nativeTypesPromoted,
			$this->templateArgumentFrame,
			$this->templateArgumentConstraints,
		);
	}

	/**
	 * @param array<string, ExpressionTypeHolder> $variableTypeHolders
	 * @param array<string, ExpressionTypeHolder> $otherVariableTypeHolders
	 * @param array<string, true>|null $writableVariableNames
	 * @return array<string, ExpressionTypeHolder>
	 */
	private function generalizeVariableTypeHolders(
		array $variableTypeHolders,
		array $otherVariableTypeHolders,
		?array $writableVariableNames,
	): array
	{
		uksort($variableTypeHolders, static fn (string $exprA, string $exprB): int => strlen($exprA) <=> strlen($exprB));

		$generalizedExpressions = [];
		$newVariableTypeHolders = [];
		foreach ($variableTypeHolders as $variableExprString => $variableTypeHolder) {
			foreach ($generalizedExpressions as $generalizedExprString => $generalizedExpr) {
				if (!ScopeOps::shouldInvalidateExpression($this, $this->services->exprPrinter, $generalizedExprString, $generalizedExpr, $variableTypeHolder->getExpr(), $variableExprString)) {
					continue;
				}

				continue 2;
			}
			if (!isset($otherVariableTypeHolders[$variableExprString])) {
				$newVariableTypeHolders[$variableExprString] = $variableTypeHolder;
				continue;
			}

			$variableExpr = $variableTypeHolder->getExpr();
			if (
				$writableVariableNames !== null
				&& $variableExpr instanceof Variable
				&& is_string($variableExpr->name)
				&& !isset($writableVariableNames[$variableExpr->name])
			) {
				// the loop does not write this variable, its types differ between passes only by narrowing
				$generalizedType = TypeCombinator::union($variableTypeHolder->getType(), $otherVariableTypeHolders[$variableExprString]->getType());
			} else {
				$generalizedType = $this->generalizeType($variableTypeHolder->getType(), $otherVariableTypeHolders[$variableExprString]->getType(), 0);
			}
			if (
				!$generalizedType->equals($variableTypeHolder->getType())
			) {
				$generalizedExpressions[$variableExprString] = $variableTypeHolder->getExpr();
			}
			$newVariableTypeHolders[$variableExprString] = new ExpressionTypeHolder(
				$variableTypeHolder->getExpr(),
				$generalizedType,
				$variableTypeHolder->getCertainty(),
			);
		}

		return $newVariableTypeHolders;
	}

	/**
	 * TypeUtils::flattenTypes() expands a shape with optional keys into every
	 * concrete variant (2^N of them, four lossy representatives above ten),
	 * only for the union below to merge them back into the very same shape -
	 * quadratic in the number of variants. The per-key widening reads the
	 * shape's keys, values and optionality directly, so only unions are split.
	 *
	 * @return list<Type>
	 */
	private function flattenUnionForGeneralization(Type $type): array
	{
		if (!$type instanceof UnionType) {
			return [$type];
		}

		$types = [];
		foreach ($type->getTypes() as $innerType) {
			foreach ($this->flattenUnionForGeneralization($innerType) as $flattenedType) {
				$types[] = $flattenedType;
			}
		}

		return $types;
	}

	private function generalizeType(Type $a, Type $b, int $depth): Type
	{
		if ($a->equals($b)) {
			return $a;
		}

		// Track whether either input carries a BenevolentUnion so the result
		// can be re-wrapped at the end. `flattenTypes` below drops the
		// BenevolentUnion wrapper, which would silently downgrade e.g.
		// `(float|int)` (numeric-accepting) to a strict `float|int`. Inside a
		// loop's fixed-point this propagates into the iterable value type of
		// an array and turns `return [..., $int]` checks into false positives
		// when the iteration body's `+ 1` arithmetic was originally produced
		// by an `ErrorType`-derived `int|float` benevolent union (the typical
		// case for reads of literally-missing keys inside the body).
		$wrapBenevolent = $a instanceof BenevolentUnionType || $b instanceof BenevolentUnionType;

		$constantIntegers = ['a' => [], 'b' => []];
		$constantFloats = ['a' => [], 'b' => []];
		$constantBooleans = ['a' => [], 'b' => []];
		$constantStrings = ['a' => [], 'b' => []];
		$constantArrays = ['a' => [], 'b' => []];
		$generalArrays = ['a' => [], 'b' => []];
		$integerRanges = ['a' => [], 'b' => []];
		$otherTypes = [];

		foreach ([
			'a' => $this->flattenUnionForGeneralization($a),
			'b' => $this->flattenUnionForGeneralization($b),
		] as $key => $types) {
			foreach ($types as $type) {
				if ($type instanceof ConstantIntegerType) {
					$constantIntegers[$key][] = $type;
					continue;
				}
				if ($type instanceof ConstantFloatType) {
					$constantFloats[$key][] = $type;
					continue;
				}
				if ($type instanceof ConstantBooleanType) {
					$constantBooleans[$key][] = $type;
					continue;
				}
				if ($type instanceof ConstantStringType) {
					$constantStrings[$key][] = $type;
					continue;
				}
				if ($type->isConstantArray()->yes()) {
					$constantArrays[$key][] = $type;
					continue;
				}
				if ($type->isArray()->yes()) {
					$generalArrays[$key][] = $type;
					continue;
				}
				if ($type instanceof IntegerRangeType) {
					$integerRanges[$key][] = $type;
					continue;
				}

				$otherTypes[] = $type;
			}
		}

		$resultTypes = [];
		foreach ([
			$constantFloats,
			$constantBooleans,
			$constantStrings,
		] as $constantTypes) {
			if (count($constantTypes['a']) === 0) {
				if (count($constantTypes['b']) > 0) {
					$resultTypes[] = TypeCombinator::union(...$constantTypes['b']);
				}
				continue;
			} elseif (count($constantTypes['b']) === 0) {
				$resultTypes[] = TypeCombinator::union(...$constantTypes['a']);
				continue;
			}

			$aTypes = TypeCombinator::union(...$constantTypes['a']);
			$bTypes = TypeCombinator::union(...$constantTypes['b']);
			if ($aTypes->equals($bTypes)) {
				$resultTypes[] = $aTypes;
				continue;
			}

			$resultTypes[] = TypeCombinator::union(...$constantTypes['a'], ...$constantTypes['b'])->generalize(GeneralizePrecision::moreSpecific());
		}

		if (count($constantArrays['a']) > 0) {
			if (count($constantArrays['b']) === 0) {
				$resultTypes[] = TypeCombinator::union(...$constantArrays['a']);
			} else {
				$constantArraysA = TypeCombinator::union(...$constantArrays['a']);
				$constantArraysB = TypeCombinator::union(...$constantArrays['b']);
				if (
					$constantArraysA->getIterableKeyType()->equals($constantArraysB->getIterableKeyType())
					&& $constantArraysA->getArraySize()->getGreaterOrEqualType($this->services->phpVersion)->isSuperTypeOf($constantArraysB->getArraySize())->yes()
				) {
					$resultArrayBuilder = ConstantArrayTypeBuilder::createEmpty();
					foreach (TypeUtils::flattenTypes($constantArraysA->getIterableKeyType()) as $keyType) {
						$resultArrayBuilder->setOffsetValueType(
							$keyType,
							$this->generalizeType(
								$constantArraysA->getOffsetValueType($keyType),
								$constantArraysB->getOffsetValueType($keyType),
								$depth + 1,
							),
							!$constantArraysA->hasOffsetValueType($keyType)->and($constantArraysB->hasOffsetValueType($keyType))->negate()->no(),
						);
					}

					$resultTypes[] = $resultArrayBuilder->getArray();
				} else {
					// Both inputs are sealed constant array shapes — their key
					// sets are finite by construction. On the fall-through
					// ArrayType path, recursing into `generalizeType` would
					// widen e.g. `0|1` to `int<0, max>` — for both the keys and
					// the values — losing the loop's per-iteration precision.
					// Keep the literal union instead so the loop's bounds stay
					// visible. (Scoped to sealed shapes so the general
					// `generalize()` widening contract for legacy arrays — see
					// ScopeTest::testGeneralize — is unaffected.)
					$bothSealed = true;
					foreach ([...$constantArrays['a'], ...$constantArrays['b']] as $constantArrayCheck) {
						foreach ($constantArrayCheck->getConstantArrays() as $constantArrayInstance) {
							if (!$constantArrayInstance->isSealed()->yes()) {
								$bothSealed = false;
								break 2;
							}
						}
					}
					if ($bothSealed) {
						$resultKeyType = TypeCombinator::union($constantArraysA->getIterableKeyType(), $constantArraysB->getIterableKeyType());
						$resultValueType = TypeCombinator::union($constantArraysA->getIterableValueType(), $constantArraysB->getIterableValueType());
						if ($resultValueType->isOversizedArray()->yes()) {
							// The literal value union outgrew the shape limit (a
							// deeply/widely nested value): fall back to generalizing
							// it into a bounded range-keyed array rather than
							// keeping an oversized literal shape.
							$resultValueType = TypeCombinator::union($this->generalizeType($constantArraysA->getIterableValueType(), $constantArraysB->getIterableValueType(), $depth + 1));
						}
					} else {
						$resultKeyType = TypeCombinator::union($this->generalizeType($constantArraysA->getIterableKeyType(), $constantArraysB->getIterableKeyType(), $depth + 1));
						$resultValueType = TypeCombinator::union($this->generalizeType($constantArraysA->getIterableValueType(), $constantArraysB->getIterableValueType(), $depth + 1));
					}
					$resultType = new ArrayType(
						$resultKeyType,
						$resultValueType,
					);
					$accessories = [];
					if (
						$constantArraysA->isIterableAtLeastOnce()->yes()
						&& $constantArraysB->isIterableAtLeastOnce()->yes()
						&& $constantArraysA->getArraySize()->getGreaterOrEqualType($this->services->phpVersion)->isSuperTypeOf($constantArraysB->getArraySize())->yes()
					) {
						$accessories[] = new NonEmptyArrayType();
					}
					if ($constantArraysA->isList()->yes() && $constantArraysB->isList()->yes()) {
						$accessories[] = new AccessoryArrayListType();
					}

					if (count($accessories) === 0) {
						$resultTypes[] = $resultType;
					} else {
						$resultTypes[] = TypeCombinator::intersect($resultType, ...$accessories);
					}
				}
			}
		} elseif (count($constantArrays['b']) > 0) {
			$resultTypes[] = TypeCombinator::union(...$constantArrays['b']);
		}

		if (count($generalArrays['a']) > 0) {
			if (count($generalArrays['b']) === 0) {
				$resultTypes[] = TypeCombinator::union(...$generalArrays['a']);
			} else {
				$generalArraysA = TypeCombinator::union(...$generalArrays['a']);
				$generalArraysB = TypeCombinator::union(...$generalArrays['b']);

				$aValueType = $generalArraysA->getIterableValueType();
				$bValueType = $generalArraysB->getIterableValueType();
				if (
					$aValueType->isArray()->yes()
					&& $aValueType->isConstantArray()->no()
					&& $bValueType->isArray()->yes()
					&& $bValueType->isConstantArray()->no()
				) {
					$aDepth = self::getArrayDepth($aValueType) + $depth;
					$bDepth = self::getArrayDepth($bValueType) + $depth;
					if (
						($aDepth > 2 || $bDepth > 2)
						&& abs($aDepth - $bDepth) > 0
					) {
						$aValueType = new MixedType();
						$bValueType = new MixedType();
					}
				}

				$resultType = new ArrayType(
					TypeCombinator::union($this->generalizeType($generalArraysA->getIterableKeyType(), $generalArraysB->getIterableKeyType(), $depth + 1)),
					TypeCombinator::union($this->generalizeType($aValueType, $bValueType, $depth + 1)),
				);

				$accessories = [];
				if ($generalArraysA->isIterableAtLeastOnce()->yes() && $generalArraysB->isIterableAtLeastOnce()->yes()) {
					$accessories[] = new NonEmptyArrayType();
				}
				if ($generalArraysA->isList()->yes() && $generalArraysB->isList()->yes()) {
					$accessories[] = new AccessoryArrayListType();
				}
				if ($generalArraysA->isOversizedArray()->yes() && $generalArraysB->isOversizedArray()->yes()) {
					$accessories[] = new OversizedArrayType();
				}

				if (count($accessories) === 0) {
					$resultTypes[] = $resultType;
				} else {
					$resultTypes[] = TypeCombinator::intersect($resultType, ...$accessories);
				}
			}
		} elseif (count($generalArrays['b']) > 0) {
			$resultTypes[] = TypeCombinator::union(...$generalArrays['b']);
		}

		if (count($constantIntegers['a']) > 0) {
			if (count($constantIntegers['b']) === 0) {
				$resultTypes[] = TypeCombinator::union(...$constantIntegers['a']);
			} else {
				$constantIntegersA = TypeCombinator::union(...$constantIntegers['a']);
				$constantIntegersB = TypeCombinator::union(...$constantIntegers['b']);

				if ($constantIntegersA->equals($constantIntegersB)) {
					$resultTypes[] = $constantIntegersA;
				} else {
					$min = null;
					$max = null;
					foreach ($constantIntegers['a'] as $int) {
						if ($min === null || $int->getValue() < $min) {
							$min = $int->getValue();
						}
						if ($max !== null && $int->getValue() <= $max) {
							continue;
						}

						$max = $int->getValue();
					}

					$newMin = $min;
					$newMax = $max;
					foreach ($constantIntegers['b'] as $int) {
						if ($int->getValue() > $newMax) {
							$newMax = $int->getValue();
						}
						if ($int->getValue() >= $newMin) {
							continue;
						}

						$newMin = $int->getValue();
					}

					if ($newMax > $max && $newMin < $min) {
						$resultTypes[] = IntegerRangeType::fromInterval($newMin, $newMax);
					} elseif ($newMax > $max) {
						$resultTypes[] = IntegerRangeType::fromInterval($min, null);
					} elseif ($newMin < $min) {
						$resultTypes[] = IntegerRangeType::fromInterval(null, $max);
					} else {
						$resultTypes[] = TypeCombinator::union($constantIntegersA, $constantIntegersB);
					}
				}
			}
		} elseif (count($constantIntegers['b']) > 0) {
			$resultTypes[] = TypeCombinator::union(...$constantIntegers['b']);
		}

		if (count($integerRanges['a']) > 0) {
			if (count($integerRanges['b']) === 0) {
				$resultTypes[] = TypeCombinator::union(...$integerRanges['a']);
			} else {
				$integerRangesA = TypeCombinator::union(...$integerRanges['a']);
				$integerRangesB = TypeCombinator::union(...$integerRanges['b']);

				if ($integerRangesA->equals($integerRangesB)) {
					$resultTypes[] = $integerRangesA;
				} else {
					$min = null;
					$max = null;
					foreach ($integerRanges['a'] as $range) {
						if ($range->getMin() === null) {
							$rangeMin = PHP_INT_MIN;
						} else {
							$rangeMin = $range->getMin();
						}
						if ($range->getMax() === null) {
							$rangeMax = PHP_INT_MAX;
						} else {
							$rangeMax = $range->getMax();
						}

						if ($min === null || $rangeMin < $min) {
							$min = $rangeMin;
						}
						if ($max !== null && $rangeMax <= $max) {
							continue;
						}

						$max = $rangeMax;
					}

					$newMin = $min;
					$newMax = $max;
					foreach ($integerRanges['b'] as $range) {
						if ($range->getMin() === null) {
							$rangeMin = PHP_INT_MIN;
						} else {
							$rangeMin = $range->getMin();
						}
						if ($range->getMax() === null) {
							$rangeMax = PHP_INT_MAX;
						} else {
							$rangeMax = $range->getMax();
						}

						if ($rangeMax > $newMax) {
							$newMax = $rangeMax;
						}
						if ($rangeMin >= $newMin) {
							continue;
						}

						$newMin = $rangeMin;
					}

					$gotGreater = $newMax > $max;
					$gotSmaller = $newMin < $min;

					if ($min === PHP_INT_MIN) {
						$min = null;
					}
					if ($max === PHP_INT_MAX) {
						$max = null;
					}
					if ($newMin === PHP_INT_MIN) {
						$newMin = null;
					}
					if ($newMax === PHP_INT_MAX) {
						$newMax = null;
					}

					if ($gotGreater && $gotSmaller) {
						$resultTypes[] = IntegerRangeType::fromInterval($newMin, $newMax);
					} elseif ($gotGreater) {
						$resultTypes[] = IntegerRangeType::fromInterval($min, null);
					} elseif ($gotSmaller) {
						$resultTypes[] = IntegerRangeType::fromInterval(null, $max);
					} else {
						$resultTypes[] = TypeCombinator::union($integerRangesA, $integerRangesB);
					}
				}
			}
		} elseif (count($integerRanges['b']) > 0) {
			$resultTypes[] = TypeCombinator::union(...$integerRanges['b']);
		}

		$accessoryTypes = array_map(
			static fn (Type $type): Type => $type->generalize(GeneralizePrecision::moreSpecific()),
			TypeUtils::getAccessoryTypes($a),
		);

		$combined = TypeCombinator::union(...$resultTypes, ...$otherTypes);
		if ($wrapBenevolent) {
			$combined = TypeUtils::toBenevolentUnion($combined);
		}

		return TypeCombinator::union(TypeCombinator::intersect(
			$combined,
			...$accessoryTypes,
		), ...$otherTypes);
	}

	private static function getArrayDepth(Type $type): int
	{
		$depth = 0;
		$arrays = TypeUtils::toBenevolentUnion($type)->getArrays();
		while (count($arrays) > 0) {
			$temp = $type->getIterableValueType();
			$type = $temp;
			$arrays = TypeUtils::toBenevolentUnion($type)->getArrays();
			$depth++;
		}

		return $depth;
	}

	public function equals(self $otherScope): bool
	{
		if (!$this->context->equals($otherScope->context)) {
			return false;
		}

		if (!$this->compareVariableTypeHolders($this->expressionTypes, $otherScope->expressionTypes)) {
			return false;
		}
		if (!$this->compareVariableTypeHolders($this->nativeExpressionTypes, $otherScope->nativeExpressionTypes)) {
			return false;
		}

		return $this->compareConditionalExpressions($this->conditionalExpressions, $otherScope->conditionalExpressions);
	}

	/**
	 * @param array<string, ConditionalExpressionHolder[]> $conditionalExpressions
	 * @param array<string, ConditionalExpressionHolder[]> $otherConditionalExpressions
	 */
	private function compareConditionalExpressions(array $conditionalExpressions, array $otherConditionalExpressions): bool
	{
		if (count($conditionalExpressions) !== count($otherConditionalExpressions)) {
			return false;
		}
		foreach ($conditionalExpressions as $exprString => $holders) {
			if (!isset($otherConditionalExpressions[$exprString])) {
				return false;
			}
			$otherHolders = $otherConditionalExpressions[$exprString];
			if (count($holders) !== count($otherHolders)) {
				return false;
			}
			foreach ($holders as $key => $holder) {
				if (!isset($otherHolders[$key])) {
					return false;
				}
				$otherHolder = $otherHolders[$key];
				if (!$holder->getTypeHolder()->equals($otherHolder->getTypeHolder())) {
					return false;
				}
				$conditions = $holder->getConditionExpressionTypeHolders();
				$otherConditions = $otherHolder->getConditionExpressionTypeHolders();
				if (count($conditions) !== count($otherConditions)) {
					return false;
				}
				foreach ($conditions as $conditionExprString => $conditionHolder) {
					if (!isset($otherConditions[$conditionExprString])) {
						return false;
					}
					if (!$conditionHolder->equals($otherConditions[$conditionExprString])) {
						return false;
					}
				}
			}
		}

		return true;
	}

	/**
	 * @param array<string, ExpressionTypeHolder> $variableTypeHolders
	 * @param array<string, ExpressionTypeHolder> $otherVariableTypeHolders
	 */
	private function compareVariableTypeHolders(array $variableTypeHolders, array $otherVariableTypeHolders): bool
	{
		if (count($variableTypeHolders) !== count($otherVariableTypeHolders)) {
			return false;
		}
		foreach ($variableTypeHolders as $variableExprString => $variableTypeHolder) {
			if (!isset($otherVariableTypeHolders[$variableExprString])) {
				return false;
			}

			if (!$variableTypeHolder->getCertainty()->equals($otherVariableTypeHolders[$variableExprString]->getCertainty())) {
				return false;
			}

			if (!$variableTypeHolder->equalTypes($otherVariableTypeHolders[$variableExprString])) {
				return false;
			}
		}

		return true;
	}

	/**
	 * @api
	 * @deprecated Use canReadProperty() or canWriteProperty()
	 */
	public function canAccessProperty(PropertyReflection $propertyReflection): bool
	{
		return $this->canAccessClassMember($propertyReflection);
	}

	/** @api */
	public function canReadProperty(ExtendedPropertyReflection $propertyReflection): bool
	{
		return $this->canAccessClassMember($propertyReflection);
	}

	/** @api */
	public function canWriteProperty(ExtendedPropertyReflection $propertyReflection): bool
	{
		if (!$propertyReflection->isPrivateSet() && !$propertyReflection->isProtectedSet()) {
			return $this->canAccessClassMember($propertyReflection);
		}

		if (!$this->services->phpVersion->supportsAsymmetricVisibility()) {
			return $this->canAccessClassMember($propertyReflection);
		}

		$propertyDeclaringClass = $propertyReflection->getDeclaringClass();
		$canAccessClassMember = static function (ClassReflection $classReflection) use ($propertyReflection, $propertyDeclaringClass) {
			if ($propertyReflection->isPrivateSet()) {
				return $classReflection->getName() === $propertyDeclaringClass->getName();
			}

			// protected set

			if (
				$classReflection->getName() === $propertyDeclaringClass->getName()
				|| $classReflection->isSubclassOfClass($propertyDeclaringClass->removeFinalKeywordOverride())
			) {
				return true;
			}

			return $propertyReflection->getDeclaringClass()->isSubclassOfClass($classReflection);
		};

		foreach ($this->inClosureBindScopeClasses as $inClosureBindScopeClass) {
			if (!$this->services->reflectionProvider->hasClass($inClosureBindScopeClass)) {
				continue;
			}

			if ($canAccessClassMember($this->services->reflectionProvider->getClass($inClosureBindScopeClass))) {
				return true;
			}
		}

		if ($this->isInClass()) {
			return $canAccessClassMember($this->getClassReflection());
		}

		return false;
	}

	/** @api */
	public function canCallMethod(MethodReflection $methodReflection): bool
	{
		if ($this->canAccessClassMember($methodReflection)) {
			return true;
		}

		return $this->canAccessClassMember($methodReflection->getPrototype());
	}

	/** @api */
	public function canAccessConstant(ClassConstantReflection $constantReflection): bool
	{
		return $this->canAccessClassMember($constantReflection);
	}

	private function canAccessClassMember(ClassMemberReflection $classMemberReflection): bool
	{
		if ($classMemberReflection->isPublic()) {
			return true;
		}

		$classMemberDeclaringClass = $classMemberReflection->getDeclaringClass();
		$canAccessClassMember = static function (ClassReflection $classReflection) use ($classMemberReflection, $classMemberDeclaringClass) {
			if ($classMemberReflection->isPrivate()) {
				return $classReflection->getName() === $classMemberDeclaringClass->getName();
			}

			// protected

			if (
				$classReflection->getName() === $classMemberDeclaringClass->getName()
				|| $classReflection->isSubclassOfClass($classMemberDeclaringClass->removeFinalKeywordOverride())
			) {
				return true;
			}

			return $classMemberReflection->getDeclaringClass()->isSubclassOfClass($classReflection);
		};

		foreach ($this->inClosureBindScopeClasses as $inClosureBindScopeClass) {
			if (!$this->services->reflectionProvider->hasClass($inClosureBindScopeClass)) {
				continue;
			}

			if ($canAccessClassMember($this->services->reflectionProvider->getClass($inClosureBindScopeClass))) {
				return true;
			}
		}

		if ($this->isInClass()) {
			return $canAccessClassMember($this->getClassReflection());
		}

		return false;
	}

	/**
	 * @return string[]
	 */
	public function debug(): array
	{
		$descriptions = [];
		foreach ($this->expressionTypes as $name => $variableTypeHolder) {
			$key = sprintf('%s (%s)', $name, $variableTypeHolder->getCertainty()->describe());
			$descriptions[$key] = $variableTypeHolder->getType()->describe(VerbosityLevel::precise());
		}
		foreach ($this->nativeExpressionTypes as $exprString => $nativeTypeHolder) {
			$key = sprintf('native %s (%s)', $exprString, $nativeTypeHolder->getCertainty()->describe());
			$descriptions[$key] = $nativeTypeHolder->getType()->describe(VerbosityLevel::precise());
		}

		foreach (array_keys($this->currentlyAssignedExpressions) as $exprString) {
			$descriptions[sprintf('currently assigned %s', $exprString)] = 'true';
		}

		foreach (array_keys($this->currentlyAllowedUndefinedExpressions) as $exprString) {
			$descriptions[sprintf('currently allowed undefined %s', $exprString)] = 'true';
		}

		foreach ($this->conditionalExpressions as $exprString => $holders) {
			foreach (array_values($holders) as $i => $holder) {
				$key = sprintf('condition about %s #%d', $exprString, $i + 1);
				$parts = [];
				foreach ($holder->getConditionExpressionTypeHolders() as $conditionalExprString => $expressionTypeHolder) {
					$parts[] = $conditionalExprString . '=' . $expressionTypeHolder->getType()->describe(VerbosityLevel::precise());
				}
				$condition = implode(' && ', $parts);
				$descriptions[$key] = sprintf(
					'if %s then %s is %s (%s)',
					$condition,
					$exprString,
					$holder->getTypeHolder()->getType()->describe(VerbosityLevel::precise()),
					$holder->getTypeHolder()->getCertainty()->describe(),
				);
			}
		}

		return $descriptions;
	}

	public function filterTypeWithMethod(Type $typeWithMethod, string $methodName): ?Type
	{
		if ($typeWithMethod instanceof UnionType) {
			$typeWithMethod = $typeWithMethod->filterTypes(static fn (Type $innerType) => $innerType->hasMethod($methodName)->yes());
			if ($typeWithMethod instanceof NeverType) {
				return null;
			}
		} elseif (!$typeWithMethod->hasMethod($methodName)->yes()) {
			return null;
		}

		return $typeWithMethod;
	}

	/** @api */
	public function getMethodReflection(Type $typeWithMethod, string $methodName): ?ExtendedMethodReflection
	{
		$type = $this->filterTypeWithMethod($typeWithMethod, $methodName);
		if ($type === null) {
			return null;
		}

		return $type->getMethod($methodName, $this);
	}

	public function getNakedMethod(Type $typeWithMethod, string $methodName): ?ExtendedMethodReflection
	{
		$type = $this->filterTypeWithMethod($typeWithMethod, $methodName);
		if ($type === null) {
			return null;
		}

		return $type->getUnresolvedMethodPrototype($methodName, $this)->getNakedMethod();
	}

	/**
	 * @api
	 * @deprecated Use getInstancePropertyReflection or getStaticPropertyReflection instead
	 */
	public function getPropertyReflection(Type $typeWithProperty, string $propertyName): ?ExtendedPropertyReflection
	{
		if ($typeWithProperty instanceof UnionType) {
			$typeWithProperty = $typeWithProperty->filterTypes(static fn (Type $innerType) => $innerType->hasProperty($propertyName)->yes());
			if ($typeWithProperty instanceof NeverType) {
				return null;
			}
		} elseif (!$typeWithProperty->hasProperty($propertyName)->yes()) {
			return null;
		}

		return $typeWithProperty->getProperty($propertyName, $this);
	}

	/** @api */
	public function getInstancePropertyReflection(Type $typeWithProperty, string $propertyName): ?ExtendedPropertyReflection
	{
		if ($typeWithProperty instanceof UnionType) {
			$typeWithProperty = $typeWithProperty->filterTypes(static fn (Type $innerType) => $innerType->hasInstanceProperty($propertyName)->yes());
			if ($typeWithProperty instanceof NeverType) {
				return null;
			}
		}
		if (!$typeWithProperty->hasInstanceProperty($propertyName)->yes()) {
			return null;
		}

		return $typeWithProperty->getInstanceProperty($propertyName, $this);
	}

	/** @api */
	public function getStaticPropertyReflection(Type $typeWithProperty, string $propertyName): ?ExtendedPropertyReflection
	{
		if ($typeWithProperty instanceof UnionType) {
			$typeWithProperty = $typeWithProperty->filterTypes(static fn (Type $innerType) => $innerType->hasStaticProperty($propertyName)->yes());
			if ($typeWithProperty instanceof NeverType) {
				return null;
			}
		}
		if (!$typeWithProperty->hasStaticProperty($propertyName)->yes()) {
			return null;
		}

		return $typeWithProperty->getStaticProperty($propertyName, $this);
	}

	public function getConstantReflection(Type $typeWithConstant, string $constantName): ?ClassConstantReflection
	{
		if ($typeWithConstant instanceof UnionType) {
			$typeWithConstant = $typeWithConstant->filterTypes(static fn (Type $innerType) => $innerType->hasConstant($constantName)->yes());

			if ($typeWithConstant instanceof NeverType) {
				return null;
			}
		} elseif (!$typeWithConstant->hasConstant($constantName)->yes()) {
			return null;
		}

		return $typeWithConstant->getConstant($constantName);
	}

	public function getConstantExplicitTypeFromConfig(string $constantName, Type $constantType): Type
	{
		return $this->services->constantResolver->resolveConstantType($constantName, $constantType);
	}

	/**
	 * @return array<string, ExpressionTypeHolder>
	 */
	private function getConstantTypes(): array
	{
		$constantTypes = [];
		foreach ($this->expressionTypes as $exprString => $typeHolder) {
			$expr = $typeHolder->getExpr();
			if (!$expr instanceof ConstFetch) {
				continue;
			}
			$constantTypes[$exprString] = $typeHolder;
		}
		return $constantTypes;
	}

	private function getGlobalConstantType(Name $name): ?Type
	{
		// the namespace only takes part for a name that is not already fully qualified
		$namespace = $name->isFullyQualified() ? null : $this->getNamespace();
		$nameString = $name->toString();
		$cacheKey = get_class($name) . "\0" . $nameString . "\0" . ($namespace ?? "\0");

		$exprStrings = self::$globalConstantFetchKeys[$cacheKey] ?? null;
		if ($exprStrings === null) {
			$exprStrings = [];
			foreach (self::createGlobalConstantFetches($name, $nameString, $namespace) as $constFetch) {
				$exprStrings[] = $this->getNodeKey($constFetch);
			}

			if (count(self::$globalConstantFetchKeys) < self::GLOBAL_CONSTANT_FETCH_KEYS_LIMIT) {
				self::$globalConstantFetchKeys[$cacheKey] = $exprStrings;
			}
		}

		foreach ($exprStrings as $i => $exprString) {
			// what hasExpressionType() does for a node that is not a Variable: the
			// key is all it looks at, and the key is exactly what is memoized above
			$typeHolder = $this->expressionTypes[$exprString] ?? null;
			if ($typeHolder === null || !$typeHolder->getCertainty()->yes()) {
				continue;
			}

			return $this->getType(self::createGlobalConstantFetches($name, $nameString, $namespace)[$i]);
		}

		return null;
	}

	/**
	 * The nodes a global constant name is looked up as, in priority order: the
	 * current namespace's constant, the global one, then the name as written.
	 *
	 * Fresh nodes on every call by design - everything that keys on node identity
	 * (ExpressionResultStorage, NodeScopeResolver's processed-node guards) must
	 * keep seeing a node of its own; only the keys they print as are memoized.
	 *
	 * @param non-empty-string $nameString
	 * @return list<ConstFetch>
	 */
	private static function createGlobalConstantFetches(Name $name, string $nameString, ?string $namespace): array
	{
		$fetches = [];
		if ($namespace !== null) {
			$fetches[] = new ConstFetch(new FullyQualified([$namespace, $nameString]));
		}

		$fetches[] = new ConstFetch(new FullyQualified($nameString));
		$fetches[] = new ConstFetch($name);

		return $fetches;
	}

	/**
	 * @return array<string, ExpressionTypeHolder>
	 */
	private function getNativeConstantTypes(): array
	{
		$constantTypes = [];
		foreach ($this->nativeExpressionTypes as $exprString => $typeHolder) {
			$expr = $typeHolder->getExpr();
			if (!$expr instanceof ConstFetch) {
				continue;
			}
			$constantTypes[$exprString] = $typeHolder;
		}
		return $constantTypes;
	}

	public function getIterableKeyType(Type $iteratee): Type
	{
		if ($iteratee instanceof UnionType) {
			$filtered = $iteratee->filterTypes(static fn (Type $innerType) => $innerType->isIterable()->yes());
			if (!$filtered instanceof NeverType) {
				$iteratee = $filtered;
			}
		}

		return $iteratee->getIterableKeyType();
	}

	public function getIterableValueType(Type $iteratee): Type
	{
		if ($iteratee instanceof UnionType) {
			$filtered = $iteratee->filterTypes(static fn (Type $innerType) => $innerType->isIterable()->yes());
			if (!$filtered instanceof NeverType) {
				$iteratee = $filtered;
			}
		}

		return $iteratee->getIterableValueType();
	}

	public function getPhpVersion(): PhpVersions
	{
		$constType = $this->getGlobalConstantType(new Name('PHP_VERSION_ID'));
		if ($constType !== null && !$this->isOverallPhpVersionRange($constType)) {
			if (
				$constType instanceof IntegerRangeType
				&& $constType->getMin() === ConstantResolver::PHP_MIN_ANALYZABLE_VERSION_ID
				&& $constType->getMax() !== null
				&& $this->getConfiguredPhpVersionRange() === null
			) {
				// A guard like `PHP_VERSION_ID < 80400` only gives an upper bound. Without
				// a configured version range, the lower bound is merely the lowest version
				// PHPStan knows, while outside the guard the single analysed PHP version
				// applies. Keep the lower bound at that version, or as close to it as
				// the guard allows.
				$maxVersionId = $constType->getMax();
				return new PhpVersions(IntegerRangeType::fromInterval(
					min($this->services->phpVersion->getVersionId(), $maxVersionId),
					$maxVersionId,
				));
			}

			return new PhpVersions($constType);
		}

		$configuredRange = $this->getConfiguredPhpVersionRange();
		if ($configuredRange !== null) {
			return new PhpVersions($configuredRange);
		}

		return new PhpVersions(new ConstantIntegerType($this->services->phpVersion->getVersionId()));
	}

	/**
	 * The analysed PHP version range comes either from the NEON phpVersion min/max
	 * config or from the composer.json "require.php" constraint - the very same
	 * source ConstantResolver narrows PHP_VERSION_ID with, so that
	 * Scope::getPhpVersion() never contradicts the PHP_VERSION_ID constant.
	 * Null when neither is set and a single PHP version is analysed.
	 */
	private function getConfiguredPhpVersionRange(): ?Type
	{
		[$minPhpVersion, $maxPhpVersion] = $this->services->configuredPhpVersionRangeHelper->getVersionRange();
		if (
			$minPhpVersion === null
			&& ($maxPhpVersion === null || $maxPhpVersion->getVersionId() === PhpVersionFactory::MAX_PHP_VERSION)
		) {
			return null;
		}

		return IntegerRangeType::fromInterval(
			$minPhpVersion !== null ? $minPhpVersion->getVersionId() : ConstantResolver::PHP_MIN_ANALYZABLE_VERSION_ID,
			$maxPhpVersion !== null ? $maxPhpVersion->getVersionId() : null,
		);
	}

	/**
	 * Whether the type carries no information about the analysed PHP version,
	 * i.e. it spans everything PHPStan is able to analyse.
	 */
	private function isOverallPhpVersionRange(Type $type): bool
	{
		return $type instanceof IntegerRangeType
			&& $type->getMin() === ConstantResolver::PHP_MIN_ANALYZABLE_VERSION_ID
			&& ($type->getMax() === null || $type->getMax() === PhpVersionFactory::MAX_PHP_VERSION);
	}

	public function invokeNodeCallback(Node $node): void
	{
		$nodeCallback = $this->services->nodeCallback;
		if ($nodeCallback === null) {
			throw new ShouldNotHappenException('Node callback is not present in this scope');
		}

		$nodeCallback($node, $this);
	}

	/**
	 * @template TNodeType of Node
	 * @template TValue
	 * @param class-string<Collector<TNodeType, TValue>> $collectorType
	 * @param TValue $data
	 */
	public function emitCollectedData(string $collectorType, mixed $data): void
	{
		$nodeCallback = $this->services->nodeCallback;
		if ($nodeCallback === null) {
			throw new ShouldNotHappenException('Node callback is not present in this scope');
		}

		$nodeCallback(new EmitCollectedDataNode($collectorType, $data), $this);
	}

	public function trackValueDependency(string $extensionClass, string $key): void
	{
		// a scope without a node callback is outside the walk of the analysed file - see ValueDependencyCollector
		$this->services->container->getByType(ValueDependencyCollector::class)->record($extensionClass, $key, $this, $this->services->nodeCallback !== null);
	}

	public function trackFileDependency(string $file): void
	{
		$this->services->container->getByType(ValueDependencyCollector::class)->recordFile($file, $this, $this->services->nodeCallback !== null);
	}

	public function trackDirectoryDependency(string $directory, string $pattern = '*'): void
	{
		$this->services->container->getByType(ValueDependencyCollector::class)->recordDirectory($directory, $pattern, $this, $this->services->nodeCallback !== null);
	}

	public function trackClassDependency(string $className): void
	{
		$this->services->container->getByType(ValueDependencyCollector::class)->recordClass($className, $this, $this->services->nodeCallback !== null);
	}

}