Add literal conversion based on context at compile time

example/main.nub

@@ -1,5 +1,17 @@
 namespace main
 
-export func main(args: []^string) {
+struct Human {
-    sys::call(60, 0)
+    age: ^u64
+}
+
+export func main(args: []^string) {
+    let x = [3]f64
+
+    x[0] = 1
+    x[1.2] = 2
+    x[2] = 3
+
+    c::printf("%d\n", x[0])
+    c::printf("%d\n", x[1])
+    c::printf("%d\n", x[2])
 }

src/lang/Nub.Lang/Frontend/Lexing/Lexer.cs

@@ -171,12 +171,6 @@ public class Lexer
                     buffer += next;
                     Next();
                 }
-                else if (next == 'f')
-                {
-                    isFloat = true;
-                    Next();
-                    break;
-                }
                 else
                 {
                     break;

src/lang/Nub.Lang/Frontend/Parsing/Definitions/FuncDefinitionNode.cs

@@ -20,37 +20,6 @@ public interface IFuncSignature
     public List<FuncParameter> Parameters { get; }
     public Optional<NubType> ReturnType { get; }
 
-    public bool SignatureMatches(string name, List<NubType> parameters)
-    {
-        if (Name != name) return false;
-        if (Parameters.Count == 0 && parameters.Count == 0) return true;
-        if (Parameters.Count > parameters.Count) return false;
-
-        for (var i = 0; i < parameters.Count; i++)
-        {
-            if (i >= Parameters.Count)
-            {
-                if (Parameters.Count > 0 && Parameters[^1].Variadic)
-                {
-                    if (!NubType.IsCompatibleWith(parameters[i], Parameters[^1].Type))
-                    {
-                        return false;
-                    }
-                }
-                else
-                {
-                    return false;
-                }
-            }
-            else if (!NubType.IsCompatibleWith(parameters[i], Parameters[i].Type))
-            {
-                return false;
-            }
-        }
-        
-        return true;
-    }
-
     public string ToString() => $"{Name}({string.Join(", ", Parameters.Select(p => p.ToString()))}){(ReturnType.HasValue ? ": " + ReturnType.Value : "")}";
 }
 

src/lang/Nub.Lang/Frontend/Parsing/Expressions/CastNode.cs

@@ -1,10 +1,10 @@
-using Nub.Lang.Frontend.Lexing;
+// using Nub.Lang.Frontend.Lexing;
-using Nub.Lang.Frontend.Typing;
+// using Nub.Lang.Frontend.Typing;
-
+//
-namespace Nub.Lang.Frontend.Parsing.Expressions;
+// namespace Nub.Lang.Frontend.Parsing.Expressions;
-
+//
-public class CastNode(IReadOnlyList<Token> tokens, NubType targetType, ExpressionNode expression) : ExpressionNode(tokens)
+// public class CastNode(IReadOnlyList<Token> tokens, NubType targetType, ExpressionNode expression) : ExpressionNode(tokens)
-{
+// {
-    public NubType TargetType { get; } = targetType;
+//     public NubType TargetType { get; } = targetType;
-    public ExpressionNode Expression { get; } = expression;
+//     public ExpressionNode Expression { get; } = expression;
-}
+// }

src/lang/Nub.Lang/Frontend/Parsing/Expressions/FuncCallNode.cs

@@ -8,5 +8,5 @@ public class FuncCallNode(IReadOnlyList<Token> tokens, string @namespace, string
     public string Name { get; } = name;
     public List<ExpressionNode> Parameters { get; } = parameters;
 
-    public override string ToString() => $"{Name}()";
+    public override string ToString() => $"{Name}::{Name}()";
 }

src/lang/Nub.Lang/Frontend/Parsing/Expressions/LiteralNode.cs

@@ -1,5 +1,4 @@
 using Nub.Lang.Frontend.Lexing;
-using Nub.Lang.Frontend.Typing;
 
 namespace Nub.Lang.Frontend.Parsing.Expressions;
 

src/lang/Nub.Lang/Frontend/Parsing/Parser.cs

@@ -499,16 +499,16 @@ public class Parser
                         expr = expression;
                         break;
                     }
-                    case Symbol.LessThan:
+                    // case Symbol.LessThan:
-                    {
+                    // {
-                        var type = ParseType();
+                    //     var type = ParseType();
-                        ExpectSymbol(Symbol.GreaterThan);
+                    //     ExpectSymbol(Symbol.GreaterThan);
-                        ExpectSymbol(Symbol.OpenParen);
+                    //     ExpectSymbol(Symbol.OpenParen);
-                        var expressionToCast = ParseExpression();
+                    //     var expressionToCast = ParseExpression();
-                        ExpectSymbol(Symbol.CloseParen);
+                    //     ExpectSymbol(Symbol.CloseParen);
-                        expr = new CastNode(GetTokensForNode(startIndex), type, expressionToCast);
+                    //     expr = new CastNode(GetTokensForNode(startIndex), type, expressionToCast);
-                        break;
+                    //     break;
-                    }
+                    // }
                     case Symbol.Ampersand:
                     {
                         var expression = ParsePrimaryExpression();

src/lang/Nub.Lang/Frontend/Typing/NubType.cs

@@ -24,6 +24,30 @@ public abstract class NubType
         return false;
     }
 
+    public bool IsInteger => this is NubPrimitiveType
+    {
+        Kind: PrimitiveTypeKind.I8
+        or PrimitiveTypeKind.I16
+        or PrimitiveTypeKind.I32
+        or PrimitiveTypeKind.I64
+        or PrimitiveTypeKind.U8
+        or PrimitiveTypeKind.U16
+        or PrimitiveTypeKind.U32
+        or PrimitiveTypeKind.U64
+    };
+    
+    public bool IsFloat32 => this is NubPrimitiveType
+    {
+        Kind: PrimitiveTypeKind.F32
+    };
+    
+    public bool IsFloat64 => this is NubPrimitiveType
+    {
+        Kind: PrimitiveTypeKind.F64
+    };
+
+    public bool IsNumber => IsFloat32 || IsFloat64 || IsInteger;
+
     public abstract override bool Equals(object? obj);
     public abstract override int GetHashCode();
     public abstract override string ToString();

src/lang/Nub.Lang/Frontend/Typing/TypeChecker.cs

@@ -71,7 +71,7 @@ public class TypeChecker
 
             if (field.Value.HasValue)
             {
-                var fieldType = TypeCheckExpression(field.Value.Value);
+                var fieldType = TypeCheckExpression(field.Value.Value, field.Type);
                 if (fieldType != null && !fieldType.Equals(field.Type))
                 {
                     ReportError("Default field initializer does not match the defined type", field.Value.Value);
@@ -153,7 +153,7 @@ public class TypeChecker
     {
         var memberType = TypeCheckExpression(memberAssignment.MemberAccess);
         if (memberType == null) return;
-        var valueType = TypeCheckExpression(memberAssignment.Value);
+        var valueType = TypeCheckExpression(memberAssignment.Value, memberType);
         if (valueType == null) return;
 
         if (!NubType.IsCompatibleWith(memberType, valueType))
@@ -166,7 +166,7 @@ public class TypeChecker
     {
         var itemType = TypeCheckExpression(arrayIndexAssignment.ArrayIndexAccess);
         if (itemType == null) return;
-        var valueType = TypeCheckExpression(arrayIndexAssignment.Value);
+        var valueType = TypeCheckExpression(arrayIndexAssignment.Value, itemType);
         if (valueType == null) return;
 
         if (!NubType.IsCompatibleWith(itemType, valueType))
@@ -177,19 +177,18 @@ public class TypeChecker
 
     private void TypeCheckVariableAssignment(VariableAssignmentNode variableAssignment)
     {
-        var valueType = TypeCheckExpression(variableAssignment.Value);
+        if (!_variables.TryGetValue(variableAssignment.Identifier.Identifier, out var variable))
-        if (valueType == null) return;
-
-        if (!_variables.TryGetValue(variableAssignment.Identifier.Identifier, out var existingVariable))
         {
             ReportError($"Variable '{variableAssignment.Identifier}' is not declared", variableAssignment);
             return;
         }
         
-        if (!NubType.IsCompatibleWith(variableAssignment.Value.Type, existingVariable))
+        var valueType = TypeCheckExpression(variableAssignment.Value, variable);
+        if (valueType == null) return;
+
+        if (!NubType.IsCompatibleWith(variableAssignment.Value.Type, variable))
         {
-            ReportError($"Cannot assign expression of type '{variableAssignment.Value.Type}' to variable '{variableAssignment.Identifier}' with type '{existingVariable}'",
+            ReportError($"Cannot assign expression of type '{variableAssignment.Value.Type}' to variable '{variableAssignment.Identifier}' with type '{variable}'",  variableAssignment);
-                variableAssignment);
         }
     }
 
@@ -197,14 +196,14 @@ public class TypeChecker
     {
         NubType? type = null;
 
-        if (_variables.TryGetValue(variableDeclaration.Name, out var existingVariable))
+        if (_variables.TryGetValue(variableDeclaration.Name, out var variable))
         {
-            ReportError($"Cannot redeclare variable '{existingVariable}'", variableDeclaration);
+            ReportError($"Cannot redeclare variable '{variable}'", variableDeclaration);
         }
 
         if (variableDeclaration.Value.HasValue)
         {
-            var valueType = TypeCheckExpression(variableDeclaration.Value.Value);
+            var valueType = TypeCheckExpression(variableDeclaration.Value.Value, variableDeclaration.ExplicitType.Value);
             if (valueType == null) return;
             type = valueType;
         }
@@ -254,31 +253,21 @@ public class TypeChecker
 
     private NubType? TypeCheckFuncCall(FuncCallNode funcCall, Node node)
     {
-        List<NubType> parameterTypes = [];
+        var funcDefinition = LookupFuncSignature(funcCall.Namespace, funcCall.Name);
-        foreach (var funcCallParameter in funcCall.Parameters)
-        {
-            var parameterType = TypeCheckExpression(funcCallParameter);
-            if (parameterType == null) return null;
-            parameterTypes.Add(parameterType);
-        }
-
-        var funcDefinition = LookupFuncSignature(funcCall.Namespace, funcCall.Name, parameterTypes);
         if (funcDefinition == null)
         {
-            ReportError($"Function '{funcCall.Name}' is not defined", node);
+            ReportError($"Function '{funcCall}' is not defined", node);
             return null;
         }
 
         if (funcDefinition.Parameters.Take(funcDefinition.Parameters.Count - 1).Any(x => x.Variadic))
         {
-            ReportError($"Function '{funcCall.Name}' has multiple variadic parameters", node);
+            ReportError($"Function '{funcCall}' has multiple variadic parameters", node);
             return null;
         }
         
         for (var i = 0; i < funcCall.Parameters.Count; i++)
         {
-            var argType = funcCall.Parameters[i].Type;
-
             NubType paramType;
             if (i < funcDefinition.Parameters.Count)
             {
@@ -290,13 +279,16 @@ public class TypeChecker
             }
             else
             {
-                ReportError($"Function '{funcCall.Name}' does not take {funcCall.Parameters.Count} parameters", node);
+                ReportError($"Function '{funcCall}' does not take {funcCall.Parameters.Count} parameters", node);
                 continue;
             }
             
+            var argType = TypeCheckExpression(funcCall.Parameters[i], paramType);
+            if (argType == null) return null;
+
             if (!NubType.IsCompatibleWith(argType, paramType))
             {
-                ReportError($"Parameter {i + 1} of function '{funcCall.Name}' expects type '{paramType}', but got '{argType}'", funcCall.Parameters[i]);
+                ReportError($"Parameter {i + 1} of function '{funcCall}' expects type '{paramType}', but got '{argType}'", funcCall.Parameters[i]);
             }
         }
 
@@ -305,7 +297,7 @@ public class TypeChecker
 
     private void TypeCheckIf(IfNode ifNode)
     {
-        var conditionType = TypeCheckExpression(ifNode.Condition);
+        var conditionType = TypeCheckExpression(ifNode.Condition, NubPrimitiveType.Bool);
         if (conditionType != null && !conditionType.Equals(NubPrimitiveType.Bool))
         {
             ReportError($"If condition must be a boolean expression, got '{conditionType}'", ifNode.Condition);
@@ -322,7 +314,7 @@ public class TypeChecker
 
     private void TypeCheckWhile(WhileNode whileNode)
     {
-        var conditionType = TypeCheckExpression(whileNode.Condition);
+        var conditionType = TypeCheckExpression(whileNode.Condition, NubPrimitiveType.Bool);
         if (conditionType != null && !conditionType.Equals(NubPrimitiveType.Bool))
         {
             ReportError($"While condition must be a boolean expression, got '{conditionType}'", whileNode.Condition);
@@ -337,7 +329,7 @@ public class TypeChecker
 
         if (returnNode.Value.HasValue)
         {
-            var returnType = TypeCheckExpression(returnNode.Value.Value);
+            var returnType = TypeCheckExpression(returnNode.Value.Value, _currentFunctionReturnType);
             if (returnType == null) return;
 
             if (_currentFunctionReturnType == null)
@@ -361,7 +353,7 @@ public class TypeChecker
     {
         var dereferenceType = TypeCheckExpression(dereferenceAssignment.Dereference);
         if (dereferenceType == null) return;
-        var valueType = TypeCheckExpression(dereferenceAssignment.Value);
+        var valueType = TypeCheckExpression(dereferenceAssignment.Value, dereferenceType);
         if (valueType == null) return;
 
         if (!NubType.IsCompatibleWith(dereferenceType, valueType))
@@ -370,17 +362,17 @@ public class TypeChecker
         }
     }
 
-    private NubType? TypeCheckExpression(ExpressionNode expression)
+    private NubType? TypeCheckExpression(ExpressionNode expression, NubType? expectedType = null)
     {
         var resultType = expression switch
         {
             AddressOfNode addressOf => TypeCheckAddressOf(addressOf),
             ArrayIndexAccessNode arrayIndex => TypeCheckArrayIndex(arrayIndex),
             ArrayInitializerNode arrayInitializer => TypeCheckArrayInitializer(arrayInitializer),
-            LiteralNode literal => TypeCheckLiteral(literal),
+            LiteralNode literal => TypeCheckLiteral(literal, expectedType),
             IdentifierNode identifier => TypeCheckIdentifier(identifier),
             BinaryExpressionNode binaryExpr => TypeCheckBinaryExpression(binaryExpr),
-            CastNode cast => TypeCheckCast(cast),
+            // CastNode cast => TypeCheckCast(cast),
             DereferenceNode dereference => TypeCheckDereference(dereference),
             FixedArrayInitializerNode fixedArray => TypeCheckFixedInitializerArray(fixedArray),
             FuncCallNode funcCallExpr => TypeCheckFuncCall(funcCallExpr, funcCallExpr),
@@ -398,15 +390,34 @@ public class TypeChecker
         return resultType;
     }
 
-    private NubType TypeCheckLiteral(LiteralNode literal)
+    private NubType? TypeCheckLiteral(LiteralNode literal, NubType? expectedType = null)
     {
+        if (expectedType != null)
+        {
+            if (expectedType.IsNumber && literal.Kind is not LiteralKind.Integer and not LiteralKind.Float)
+            {
+                ReportError("Expression expects a numeric literal", literal);
+                return null;
+            }
+            
+            if (expectedType.IsInteger && literal.Kind == LiteralKind.Float)
+            {
+                if (literal.Kind == LiteralKind.Float)
+                {
+                    ReportWarning("Possible loss of precision when using float in integer context", literal);
+                }
+            }
+
+            return expectedType;
+        }
+
         return literal.Kind switch
         {
             LiteralKind.Integer => NubPrimitiveType.I64,
             LiteralKind.Float => NubPrimitiveType.F64,
             LiteralKind.String => NubPrimitiveType.String,
             LiteralKind.Bool => NubPrimitiveType.Bool,
-            _ => throw new UnreachableException()
+            _ => throw new ArgumentOutOfRangeException()
         };
     }
 
@@ -414,10 +425,10 @@ public class TypeChecker
     {
         var expressionType = TypeCheckExpression(arrayIndexAccess.Array);
         if (expressionType == null) return null;
-        var indexType = TypeCheckExpression(arrayIndexAccess.Index);
+        var indexType = TypeCheckExpression(arrayIndexAccess.Index, NubPrimitiveType.U64);
-        if (indexType != null && !IsInteger(indexType))
+        if (indexType is { IsInteger: false })
         {
-            ReportError("Array index type must be an integer", arrayIndexAccess.Index);
+            ReportError("Array index type must be a number", arrayIndexAccess.Index);
         }
         
         if (expressionType is NubArrayType arrayType)
@@ -436,8 +447,8 @@ public class TypeChecker
 
     private NubType TypeCheckArrayInitializer(ArrayInitializerNode arrayInitializer)
     {
-        var capacityType = TypeCheckExpression(arrayInitializer.Capacity);
+        var capacityType = TypeCheckExpression(arrayInitializer.Capacity, NubPrimitiveType.U64);
-        if (capacityType != null && !IsInteger(capacityType))
+        if (capacityType is { IsInteger: false })
         {
             ReportError("Array capacity type must be an integer", arrayInitializer.Capacity);
         }
@@ -516,12 +527,12 @@ public class TypeChecker
         }
     }
 
-    private NubType? TypeCheckCast(CastNode cast)
+    // private NubType? TypeCheckCast(CastNode cast)
-    {
+    // {
-        TypeCheckExpression(cast.Expression);
+    //     TypeCheckExpression(cast.Expression, cast.TargetType);
-        // TODO: Check if castable
+    //     // TODO: Check if castable
-        return cast.TargetType;
+    //     return cast.TargetType;
-    }
+    // }
 
     private NubType? TypeCheckStructInitializer(StructInitializerNode structInit)
     {
@@ -543,7 +554,7 @@ public class TypeChecker
                 continue;
             }
 
-            var initializerType = TypeCheckExpression(initializer.Value);
+            var initializerType = TypeCheckExpression(initializer.Value, definitionField.Type);
             if (initializerType != null && !NubType.IsCompatibleWith(initializerType, definitionField.Type))
             {
                 ReportError($"Cannot initialize field '{initializer.Key}' of type '{definitionField.Type}' with expression of type '{initializerType}'", initializer.Value);
@@ -654,6 +665,12 @@ public class TypeChecker
         _diagnostics.Add(diagnostic);
     }
 
+    private void ReportWarning(string message, Node node)
+    {
+        var diagnostic = Diagnostic.Warning(message).At(node).Build();
+        _diagnostics.Add(diagnostic);
+    }
+
     private static bool IsNumeric(NubType type)
     {
         if (type is not NubPrimitiveType primitiveType)
@@ -679,36 +696,13 @@ public class TypeChecker
         }
     }
 
-    private static bool IsInteger(NubType type)
+    private IFuncSignature? LookupFuncSignature(string @namespace, string name)
-    {
-        if (type is not NubPrimitiveType primitiveType)
-        {
-            return false;
-        }
-
-        switch (primitiveType.Kind)
-        {
-            case PrimitiveTypeKind.I8:
-            case PrimitiveTypeKind.I16:
-            case PrimitiveTypeKind.I32:
-            case PrimitiveTypeKind.I64:
-            case PrimitiveTypeKind.U8:
-            case PrimitiveTypeKind.U16:
-            case PrimitiveTypeKind.U32:
-            case PrimitiveTypeKind.U64:
-                return true;
-            default:
-                return false;
-        }
-    }
-
-    private IFuncSignature? LookupFuncSignature(string @namespace, string name, List<NubType> parameters)
     {
         return _sourceFiles
             .Where(f => f.Namespace == @namespace)
             .SelectMany(f => f.Definitions)
             .OfType<IFuncSignature>()
-            .FirstOrDefault(f => f.SignatureMatches(name, parameters));
+            .FirstOrDefault(f => f.Name == name);
     }
 
     private StructDefinitionNode? LookupStructDefinition(string @namespace, string name)
@@ -717,6 +711,6 @@ public class TypeChecker
             .Where(f => f.Namespace == @namespace)
             .SelectMany(f => f.Definitions)
             .OfType<StructDefinitionNode>()
-            .FirstOrDefault(d => d.Name == name);
+            .SingleOrDefault(d => d.Name == name);
     }
 }