Fix value conversions, Lua string coercion and stream reads

src/Lua/IO/MemoryStreams.cs

@@ -112,18 +112,6 @@ public virtual ValueTask<string> ReadAllAsync(CancellationToken cancellationToke
         }
 
         var remaining = contents[Position..].Span;
-        var startPos = Position;
-
-        // Use the shared utility to scan for a number
-        var numberLength = NumberReaderHelper.ScanNumberLength(remaining, true);
-
-        if (numberLength == 0)
-        {
-            Position = contents.Length;
-            return new((double?)null);
-        }
-
-        // Find where the actual number starts (after whitespace)
         var whitespaceLength = 0;
         while (
             whitespaceLength < remaining.Length && char.IsWhiteSpace(remaining[whitespaceLength])
@@ -132,12 +120,10 @@ public virtual ValueTask<string> ReadAllAsync(CancellationToken cancellationToke
             whitespaceLength++;
         }
 
-        var numberSpan = remaining.Slice(whitespaceLength, numberLength);
-        Position = startPos + whitespaceLength + numberLength;
-
-        // Parse using shared utility
-        var result = NumberReaderHelper.ParseNumber(numberSpan);
-        return new(result);
+        remaining = remaining[whitespaceLength..];
+        var numberLength = NumberReaderHelper.ScanNumberLength(remaining);
+        Position += whitespaceLength + numberLength;
+        return new(NumberReaderHelper.ParseNumber(remaining[..numberLength]));
     }
 
     public ValueTask WriteAsync(ReadOnlyMemory<char> content, CancellationToken cancellationToken)
@@ -200,6 +186,7 @@ public override ValueTask<string> ReadAllAsync(CancellationToken cancellationTok
         cancellationToken.ThrowIfCancellationRequested();
         if (Position == 0)
         {
+            Position = content.Length;
             return new(content);
         }
 

src/Lua/IO/NumberReaderHelper.cs

@@ -10,27 +10,16 @@ internal static class NumberReaderHelper
     /// Returns the length of the number portion, or 0 if no valid number is found.
     /// </summary>
     /// <param name="span">The span to scan</param>
-    /// <param name="skipWhitespace">Whether to skip leading whitespace</param>
     /// <returns>The length of the valid number portion</returns>
-    public static int ScanNumberLength(ReadOnlySpan<char> span, bool skipWhitespace = true)
+    public static int ScanNumberLength(ReadOnlySpan<char> span)
     {
         var position = 0;
 
-        // Skip leading whitespace
-        if (skipWhitespace)
-        {
-            while (position < span.Length && char.IsWhiteSpace(span[position]))
-            {
-                position++;
-            }
-        }
-
         if (position >= span.Length)
         {
             return 0;
         }
 
-        var numberStart = position;
         var hasStarted = false;
         var isHex = false;
         var hasDecimal = false;
@@ -129,7 +118,7 @@ public static int ScanNumberLength(ReadOnlySpan<char> span, bool skipWhitespace
         }
 
         // Return the length of the number portion
-        return position - numberStart;
+        return position;
     }
 
     public static bool TryParseToDouble(ReadOnlySpan<char> span, out double result)

src/Lua/LuaFunctionExecutionContext.cs

@@ -67,6 +67,23 @@ public T GetArgument<T>(int index)
         return ReadArgument<T>(index, in Arguments[index]);
     }
 
+    // Lua library strings accept numbers; typed C# arguments remain strict.
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    internal string GetStringArgument(int index)
+    {
+        var argument = GetArgument(index);
+        if (argument.TryReadString(out var text))
+            return text;
+        if (argument.Type == LuaValueType.Number)
+        {
+            text = argument.ToLuaString(State.Platform.NumberFormat);
+            State.Stack.Get(FrameBase + index) = text;
+            return text;
+        }
+        ThrowArgumentError<string>(index, argument);
+        return null!;
+    }
+
     [MethodImpl(MethodImplOptions.AggressiveInlining)]
     internal T GetArgumentOrDefault<T>(int index, T defaultValue = default!)
     {
@@ -110,7 +127,10 @@ T ReadArgument<T>(int index, in LuaValue arg)
     void ThrowArgumentError<T>(int index, in LuaValue arg)
     {
         var t = typeof(T);
-        if ((t == typeof(int) || t == typeof(long)) && arg.TryReadNumber(out _))
+        if (
+            (t == typeof(int) || t == typeof(long) || t == typeof(uint) || t == typeof(ulong))
+            && arg.TryReadNumber(out _)
+        )
         {
             LuaRuntimeException.BadArgumentNumberIsNotInteger(State, index + 1);
         }

src/Lua/LuaValue.cs

@@ -64,7 +64,7 @@ public bool TryRead<T>(out T result)
                 }
                 else if (t == typeof(int))
                 {
-                    if (!MathEx.IsInteger(value))
+                    if (!MathEx.IsInteger(value) || value < int.MinValue || value > int.MaxValue)
                     {
                         break;
                     }
@@ -75,7 +75,12 @@ public bool TryRead<T>(out T result)
                 }
                 else if (t == typeof(long))
                 {
-                    if (!MathEx.IsInteger(value))
+                    // The upper bound is exclusive: long.MaxValue rounds to 2^63 as a double.
+                    if (
+                        !MathEx.IsInteger(value)
+                        || value < long.MinValue
+                        || value >= 9223372036854775808d
+                    )
                     {
                         break;
                     }
@@ -86,23 +91,23 @@ public bool TryRead<T>(out T result)
                 }
                 else if (t == typeof(uint))
                 {
-                    if (!MathEx.IsInteger(value))
+                    if (!MathEx.IsInteger(value) || value < 0 || value > uint.MaxValue)
                     {
                         break;
                     }
 
-                    var v = checked((uint)value);
+                    var v = (uint)value;
                     result = Unsafe.As<uint, T>(ref v);
                     return true;
                 }
                 else if (t == typeof(ulong))
                 {
-                    if (!MathEx.IsInteger(value))
+                    if (!MathEx.IsInteger(value) || value < 0 || value >= 18446744073709551616d)
                     {
                         break;
                     }
 
-                    var v = checked((ulong)value);
+                    var v = (ulong)value;
                     result = Unsafe.As<ulong, T>(ref v);
                     return true;
                 }
@@ -124,7 +129,7 @@ public bool TryRead<T>(out T result)
                 }
                 else if (t == typeof(object))
                 {
-                    result = (T)(object)value;
+                    result = (T)(object)(value != 0);
                     return true;
                 }
                 else

src/Lua/Standard/BasicLibrary.cs

@@ -109,7 +109,7 @@ CancellationToken cancellationToken
     {
         if (context.HasArgument(0))
         {
-            var option = context.GetArgument<string>(0);
+            var option = context.GetStringArgument(0);
             if (!KnownCollectGarbageOptions.Contains(option))
             {
                 throw new LuaRuntimeException(
@@ -129,7 +129,7 @@ public async ValueTask<int> DoFile(
         CancellationToken cancellationToken
     )
     {
-        var arg0 = context.GetArgument<string>(0);
+        var arg0 = context.GetStringArgument(0);
         context.State.Stack.PopUntil(context.ReturnFrameBase);
         var closure = await context.State.LoadFileAsync(
             context.State.Platform.DecodeText(arg0),
@@ -217,8 +217,8 @@ public async ValueTask<int> LoadFile(
         CancellationToken cancellationToken
     )
     {
-        var arg0 = context.GetArgument<string>(0);
-        var mode = context.HasArgument(1) ? context.GetArgument<string>(1) : "bt";
+        var arg0 = context.GetStringArgument(0);
+        var mode = context.HasArgument(1) ? context.GetStringArgument(1) : "bt";
         var hasEnvironment = context.ArgumentCount > 2;
         var environment = hasEnvironment ? context.GetArgument(2) : LuaValue.Nil;
 
@@ -251,9 +251,9 @@ CancellationToken cancellationToken
     {
         var arg0 = context.GetArgument(0);
 
-        var name = context.HasArgument(1) ? context.GetArgument<string>(1) : null;
+        var name = context.HasArgument(1) ? context.GetStringArgument(1) : null;
 
-        var mode = context.HasArgument(2) ? context.GetArgument<string>(2) : "bt";
+        var mode = context.HasArgument(2) ? context.GetStringArgument(2) : "bt";
 
         var hasEnvironment = context.ArgumentCount > 3;
         var environment = hasEnvironment ? context.GetArgument(3) : LuaValue.Nil;

src/Lua/Standard/FileHandle.cs

@@ -244,8 +244,8 @@ static async (context, cancellationToken) =>
         (context, cancellationToken) =>
         {
             var file = context.GetArgument<FileHandle>(0);
-            var whence = context.HasArgument(1) ? context.GetArgument<string>(1) : "cur";
-            var offset = context.HasArgument(2) ? context.GetArgument<int>(2) : 0;
+            var whence = context.HasArgument(1) ? context.GetStringArgument(1) : "cur";
+            var offset = context.HasArgument(2) ? context.GetArgument<long>(2) : 0;
 
             if (whence is not ("set" or "cur" or "end"))
             {
@@ -257,7 +257,7 @@ static async (context, cancellationToken) =>
 
             try
             {
-                return new(context.Return(file.Seek(whence, (long)offset)));
+                return new(context.Return(file.Seek(whence, offset)));
             }
             catch (IOException ex)
             {
@@ -277,7 +277,7 @@ static async (context, cancellationToken) =>
         (context, cancellationToken) =>
         {
             var file = context.GetArgument<FileHandle>(0);
-            var mode = context.GetArgument<string>(1);
+            var mode = context.GetStringArgument(1);
             var size = context.HasArgument(2) ? context.GetArgument<int>(2) : -1;
 
             file.SetVBuf(mode, size);

src/Lua/Standard/IOLibrary.cs

@@ -149,7 +149,7 @@ static async (context, cancellationToken) =>
         }
         else
         {
-            var fileName = context.GetArgument<string>(0);
+            var fileName = context.GetStringArgument(0);
             LuaValue[] formats =
                 context.ArgumentCount > 1
                     ? context.Arguments[1..context.ArgumentCount].ToArray()
@@ -207,8 +207,8 @@ public async ValueTask<int> Open(
         CancellationToken cancellationToken
     )
     {
-        var fileName = context.GetArgument<string>(0);
-        var mode = context.HasArgument(1) ? context.GetArgument<string>(1) : "r";
+        var fileName = context.GetStringArgument(0);
+        var mode = context.HasArgument(1) ? context.GetStringArgument(1) : "r";
         context.Return();
         try
         {

src/Lua/Standard/ModuleLibrary.cs

@@ -24,7 +24,7 @@ public async ValueTask<int> Require(
         CancellationToken cancellationToken
     )
     {
-        var arg0 = context.GetArgument<string>(0);
+        var arg0 = context.GetStringArgument(0);
         var loaded = context.GlobalState.LoadedModules;
 
         if (!loaded.TryGetValue(arg0, out var loadedTable))
@@ -74,10 +74,10 @@ public ValueTask<int> SearchPath(
         CancellationToken cancellationToken
     )
     {
-        var name = context.GetArgument<string>(0);
-        var path = context.GetArgument<string>(1);
-        var separator = context.GetArgument<string>(2);
-        var dirSeparator = context.GetArgument<string>(3);
+        var name = context.GetStringArgument(0);
+        var path = context.GetStringArgument(1);
+        var separator = context.GetStringArgument(2);
+        var dirSeparator = context.GetStringArgument(3);
         var fileName = SearchPath(context.State, name, path, separator, dirSeparator);
         return new(context.Return(fileName ?? LuaValue.Nil));
     }
@@ -170,7 +170,7 @@ public ValueTask<int> SearcherPreload(
         CancellationToken cancellationToken
     )
     {
-        var name = context.GetArgument<string>(0);
+        var name = context.GetStringArgument(0);
         var preload = context.GlobalState.PreloadModules[name];
         if (preload == LuaValue.Nil)
         {
@@ -185,7 +185,7 @@ public async ValueTask<int> SearcherLua(
         CancellationToken cancellationToken
     )
     {
-        var name = context.GetArgument<string>(0);
+        var name = context.GetStringArgument(0);
         var fileName = await FindFile(
             context.State,
             name,

src/Lua/Standard/OpenLibsExtensions.cs

@@ -141,7 +141,7 @@ public static void OpenStringLibrary(this LuaState state)
             "index",
             (context, cancellationToken) =>
             {
-                context.GetArgument<string>(0);
+                context.GetStringArgument(0);
                 var key = context.GetArgument(1);
                 return new(context.Return(@string[key]));
             }

src/Lua/Standard/OperatingSystemLibrary.cs

@@ -41,9 +41,7 @@ public ValueTask<int> Date(
         CancellationToken cancellationToken
     )
     {
-        var format = context.HasArgument(0)
-            ? context.GetArgument<string>(0).AsSpan()
-            : "%c".AsSpan();
+        var format = context.HasArgument(0) ? context.GetStringArgument(0).AsSpan() : "%c".AsSpan();
         if (format.IsEmpty)
             return new(context.Return(""));
 
@@ -155,7 +153,7 @@ public ValueTask<int> GetEnv(
         CancellationToken cancellationToken
     )
     {
-        var variable = context.GetArgument<string>(0);
+        var variable = context.GetStringArgument(0);
         var platform = context.State.Platform;
         var value = platform.OsEnvironment.GetEnvironmentVariable(platform.DecodeText(variable));
         return new(context.Return(value is null ? LuaValue.Nil : platform.EncodeText(value)));
@@ -166,7 +164,7 @@ public async ValueTask<int> Remove(
         CancellationToken cancellationToken
     )
     {
-        var fileName = context.GetArgument<string>(0);
+        var fileName = context.GetStringArgument(0);
         try
         {
             await context.GlobalState.Platform.FileSystem.Remove(
@@ -190,8 +188,8 @@ public async ValueTask<int> Rename(
         CancellationToken cancellationToken
     )
     {
-        var oldName = context.GetArgument<string>(0);
-        var newName = context.GetArgument<string>(1);
+        var oldName = context.GetStringArgument(0);
+        var newName = context.GetStringArgument(1);
         try
         {
             await context.GlobalState.Platform.FileSystem.Rename(
@@ -218,7 +216,7 @@ CancellationToken cancellationToken
     {
         // os.setlocale is not supported besides the standard "C" POSIX locale
         // Any locale besides "C" will return nil
-        var locale = context.GetArgument<string>(0);
+        var locale = context.GetStringArgument(0);
         if (locale == "C")
         {
             return new(context.Return(locale));