refactor: simplify raise() to always-throw, remove setErrorHandling

- raise() now returns 'never' — all errors always throw (data integrity)
- Remove setErrorHandling/getErrorHandling/ErrorHandlingMode (global mutable state risk)
- Remove all fallback returns after raise() (unreachable with never type)
- Rationale: silent data corruption worse than crash for data structures
- 2602 tests, 83 suites, 0 failures

Author: zrwusa

docs-site-docusaurus/docs/guide/guides.md

@@ -588,23 +588,6 @@ const result = tree
   .reduce((sum, v) => sum + (v ?? 0), 0);
 ```
 
-### 5. Configure Error Handling
-
-```typescript
-import { setErrorHandling, getErrorHandling } from 'data-structure-typed';
-
-// Default: throws errors
-setErrorHandling('throw');
-
-// In production: log instead of crash
-setErrorHandling('warn');   // console.warn
-setErrorHandling('error');  // console.error
-setErrorHandling('silent'); // suppress entirely
-
-// Check current mode
-console.log(getErrorHandling()); // 'silent'
-```
-
 ---
 
 **Need more?** Check [INTEGRATIONS.md](/guide/integrations.md) for framework examples.

docs/rfcs/order-statistic-tree.md

@@ -283,25 +283,12 @@ Called after every structural change (rotation, insert fixup, delete fixup).
 
 ## Error Handling
 
-Uses the library's centralized error handling system (`raise` from `src/common/error.ts`).
-
-### Global error handling modes
-
-```ts
-import { setErrorHandling } from 'data-structure-typed';
-
-setErrorHandling('throw'); // default — fail-fast
-setErrorHandling('warn');  // console.warn and continue
-setErrorHandling('error'); // console.error and continue
-setErrorHandling('silent');// suppress all
-```
-
-### Usage in order-statistic methods
+Uses the library's centralized `raise()` from `src/common/error.ts`. All errors always throw (data structure errors are never recoverable — silent failures cause data corruption).
 
 ```ts
 select(k: number): K | undefined {
   if (!this._enableOrderStatistic) {
-    raise(Error, ERR.orderStatisticNotEnabled('select'));
+    raise(Error, ERR.orderStatisticNotEnabled('select')); // always throws
     return undefined; // reached in warn/error/silent modes
   }
   // ...

src/common/error.ts

@@ -1,51 +1,15 @@
 /**
- * Error handling mode for the library.
- * - 'throw': Throw errors (default, fail-fast)
- * - 'warn': console.warn and continue
- * - 'error': console.error and continue
- * - 'silent': Suppress all errors
- */
-export type ErrorHandlingMode = 'throw' | 'warn' | 'error' | 'silent';
-
-let _errorHandlingMode: ErrorHandlingMode = 'throw';
-
-/**
- * Set the global error handling mode.
- * @param mode - The error handling mode to use.
- */
-export function setErrorHandling(mode: ErrorHandlingMode): void {
-  _errorHandlingMode = mode;
-}
-
-/**
- * Get the current error handling mode.
- */
-export function getErrorHandling(): ErrorHandlingMode {
-  return _errorHandlingMode;
-}
-
-/**
- * Raise an error through the configured error handling mode.
- * In 'throw' mode, throws the error. In other modes, logs and continues.
+ * Centralized error dispatch.
+ * All library errors go through this function for consistent messaging and easy grep.
+ * @remarks Always throws — data structure errors are never recoverable.
  * @param ErrorClass - The error constructor (Error, TypeError, RangeError, etc.)
  * @param message - The error message.
  */
 export function raise(
   ErrorClass: new (msg: string) => Error,
   message: string
-): void {
-  switch (_errorHandlingMode) {
-    case 'throw':
-      throw new ErrorClass(message);
-    case 'warn':
-      console.warn(`[data-structure-typed] ${message}`);
-      break;
-    case 'error':
-      console.error(`[data-structure-typed] ${message}`);
-      break;
-    case 'silent':
-      break;
-  }
+): never {
+  throw new ErrorClass(message);
 }
 
 /**

src/common/index.ts

@@ -1,5 +1,4 @@
-export { ERR, raise, setErrorHandling, getErrorHandling } from './error';
-export type { ErrorHandlingMode } from './error';
+export { ERR, raise } from './error';
 
 export enum DFSOperation {
   VISIT = 0,

src/data-structures/binary-tree/bst.ts

@@ -1217,7 +1217,6 @@ export class BST<K = any, V = any, R = any> extends BinaryTree<K, V, R> implemen
   ): K | undefined | ReturnType<C> | undefined {
     if (!this._enableOrderStatistic) {
       raise(Error, ERR.orderStatisticNotEnabled('select'));
-      return undefined;
     }
     if (k < 0 || k >= this._size) return undefined;
 
@@ -1290,7 +1289,6 @@ export class BST<K = any, V = any, R = any> extends BinaryTree<K, V, R> implemen
   ): number {
     if (!this._enableOrderStatistic) {
       raise(Error, ERR.orderStatisticNotEnabled('rank'));
-      return -1;
     }
     if (!this._root || this._size === 0) return -1;
 
@@ -1357,7 +1355,6 @@ export class BST<K = any, V = any, R = any> extends BinaryTree<K, V, R> implemen
   ): (K | undefined)[] | ReturnType<C>[] {
     if (!this._enableOrderStatistic) {
       raise(Error, ERR.orderStatisticNotEnabled('rangeByRank'));
-      return [];
     }
     if (this._size === 0) return [];
 

src/data-structures/binary-tree/tree-map.ts

@@ -65,7 +65,6 @@ export class TreeMap<K = any, V = any, R = [K, V]> implements Iterable<[K, V | u
         // Validate entries like native Map: each item must be a 2-tuple-like value.
         if (!Array.isArray(item) || item.length < 2) {
           raise(TypeError, ERR.invalidEntry('TreeMap'));
-          continue;
         }
         k = item[0] as K;
         v = item[1] as V | undefined;
@@ -108,7 +107,6 @@ export class TreeMap<K = any, V = any, R = [K, V]> implements Iterable<[K, V | u
       }
 
       raise(TypeError, ERR.comparatorRequired('TreeMap'));
-      return 0;
     };
   }
 

src/data-structures/binary-tree/tree-set.ts

@@ -92,7 +92,6 @@ export class TreeSet<K = any, R = K> implements Iterable<K> {
       }
 
       raise(TypeError, ERR.comparatorRequired('TreeSet'));
-      return 0;
     };
   }
 

src/data-structures/graph/abstract-graph.ts

@@ -276,7 +276,6 @@ export abstract class AbstractGraph<
         return this._addEdge(newEdge);
       } else {
         raise(TypeError, ERR.invalidArgument('dest must be a Vertex or vertex key when srcOrEdge is an Edge.', 'Graph'));
-        return false;
       }
     }
   }

src/data-structures/hash/hash-map.ts

@@ -953,7 +953,6 @@ export class LinkedHashMap<K = any, V = any, R = [K, V]> extends IterableEntryBa
       return rawElement;
     }
     raise(TypeError, ERR.invalidArgument('If elements do not adhere to [key, value], provide options.toEntryFn to transform raw records.', 'HashMap'));
-    return rawElement as unknown as [K, V];
   };
 
   get toEntryFn() {

src/data-structures/linked-list/skip-linked-list.ts

@@ -102,7 +102,6 @@ export class SkipList<K = any, V = any, R = [K, V]> extends IterableEntryBase<K,
         return a < b ? -1 : a > b ? 1 : 0;
       }
       raise(TypeError, ERR.comparatorRequired('SkipList'));
-      return 0;
     };
   }