private void ResolveBodyTypesInField(FieldDeclarationSyntax fieldDeclaration)
{
if (fieldDeclaration.Initializer == null) return;
var resolver = new ExpressionTypeResolver(fieldDeclaration.File, diagnostics);
resolver.CheckExpressionType(fieldDeclaration.Initializer, fieldDeclaration.Type.Fulfilled());
}
private void ResolveSignatureTypesInFunction(FunctionDeclarationSyntax function)
{
function.Type.BeginFulfilling();
var diagnosticCount = diagnostics.Count;
// Resolve the declaring type because we need its type for things like `self`
if (function.DeclaringType != null)
ResolveSignatureTypesInTypeDeclaration(function.DeclaringType);
var selfType = ResolveSelfType(function);
var resolver = new ExpressionTypeResolver(function.File, diagnostics, selfType);
if (function.GenericParameters != null)
ResolveTypesInGenericParameters(function.GenericParameters, resolver);
var parameterTypes = ResolveTypesInParameters(function, resolver);
var returnType = ResolveReturnType(function, resolver);
DataType functionType = new FunctionType(parameterTypes, returnType);
if (function.GenericParameters?.Any() ?? false)
functionType = new MetaFunctionType(function.GenericParameters.Select(p => p.Type.Fulfilled()), functionType);
function.Type.Fulfill(functionType);
if (diagnosticCount != diagnostics.Count) function.Poison();
}
private void ResolveSignatureTypesInField(FieldDeclarationSyntax field)
{
var resolver = new ExpressionTypeResolver(field.File, diagnostics);
field.Type.BeginFulfilling();
var type = resolver.CheckAndEvaluateTypeExpression(field.TypeExpression);
field.Type.Fulfill(type);
}
private FixedList<DataType> ResolveTypesInParameters(
FunctionDeclarationSyntax function,
ExpressionTypeResolver expressionResolver)
{
var types = new List<DataType>();
foreach (var parameter in function.Parameters)
switch (parameter)
{
case NamedParameterSyntax namedParameter:
{
parameter.Type.BeginFulfilling();
var type =
expressionResolver.CheckAndEvaluateTypeExpression(namedParameter
.TypeExpression);
types.Add(parameter.Type.Fulfill(type));
}
break;
case SelfParameterSyntax _:
// Skip, we have already handled the self parameter
break;
case FieldParameterSyntax fieldParameter:
throw new NotImplementedException();
default:
throw NonExhaustiveMatchException.For(parameter);
}
return types.ToFixedList();
}
private static DataType ResolveReturnType(
FunctionDeclarationSyntax function,
ExpressionSyntax returnTypeExpression,
ExpressionTypeResolver expressionResolver)
{
var returnType = returnTypeExpression != null
? expressionResolver.CheckAndEvaluateTypeExpression(returnTypeExpression)
: DataType.Void;
return function.ReturnType.Fulfill(returnType);
}
private void ResolveBodyTypesInFunction(FunctionDeclarationSyntax function)
{
if (function.Body == null) return;
var diagnosticCount = diagnostics.Count;
// TODO the return types of constructors and init functions should probably be void for purposes of expressions
var resolver = new ExpressionTypeResolver(function.File, diagnostics, (Metatype)function.DeclaringType?.Type.Fulfilled(), function.ReturnType.Fulfilled());
// The body of a function shouldn't itself evaluate to anything.
// There should be no `=> value` for the block, so the type is `void`.
resolver.CheckExpressionType(function.Body, DataType.Void);
if (diagnosticCount != diagnostics.Count) function.Poison();
}
private static void ResolveTypesInGenericParameters(
FixedList<GenericParameterSyntax> genericParameters,
ExpressionTypeResolver expressionResolver)
{
foreach (var parameter in genericParameters)
{
parameter.Type.BeginFulfilling();
var type = parameter.TypeExpression == null ?
DataType.Type
: expressionResolver.CheckAndEvaluateTypeExpression(parameter.TypeExpression);
parameter.Type.Fulfill(type);
}
}
private static DataType ResolveReturnType(
FunctionDeclarationSyntax function,
ExpressionTypeResolver expressionResolver)
{
function.ReturnType.BeginFulfilling();
switch (function)
{
case NamedFunctionDeclarationSyntax namedFunction:
return ResolveReturnType(function, namedFunction.ReturnTypeExpression, expressionResolver);
case OperatorDeclarationSyntax @operator:
return ResolveReturnType(function, @operator.ReturnTypeExpression, expressionResolver);
case ConstructorDeclarationSyntax _:
case InitializerDeclarationSyntax _:
return function.ReturnType.Fulfill(function.DeclaringType.Metatype.Instance);
default:
throw NonExhaustiveMatchException.For(function);
}
}
/// <summary>
/// If the type has not been resolved, this resolves it. This function
/// also watches for type cycles and reports an error.
/// </summary>
private void ResolveSignatureTypesInTypeDeclaration(TypeDeclarationSyntax declaration)
{
switch (declaration.Type.State)
{
case PromiseState.InProgress:
diagnostics.Add(TypeError.CircularDefinition(declaration.File, declaration.NameSpan, declaration.Name));
return;
case PromiseState.Fulfilled:
return; // We have already resolved it
case PromiseState.Pending:
// we need to compute it
break;
}
declaration.Type.BeginFulfilling();
var expressionChecker = new ExpressionTypeResolver(declaration.File, diagnostics);
FixedList<DataType> genericParameterTypes = null;
if (declaration.GenericParameters != null)
{
var genericParameters = declaration.GenericParameters;
ResolveTypesInGenericParameters(genericParameters, expressionChecker);
genericParameterTypes = genericParameters.Select(p => p.Type.Fulfilled()).ToFixedList();
}
switch (declaration)
{
case ClassDeclarationSyntax classDeclaration:
var classType = new ObjectType(declaration,
classDeclaration.Modifiers.Any(m => m is IMutableKeywordToken),
genericParameterTypes,
Lifetime.None);
declaration.Type.Fulfill(new Metatype(classType));
classDeclaration.CreateDefaultConstructor();
break;
case StructDeclarationSyntax structDeclaration:
var structType = new ObjectType(declaration,
structDeclaration.Modifiers.Any(m => m is IMutableKeywordToken),
genericParameterTypes,
Lifetime.None);
declaration.Type.Fulfill(new Metatype(structType));
break;
case EnumStructDeclarationSyntax enumStructDeclaration:
var enumStructType = new ObjectType(declaration,
enumStructDeclaration.Modifiers.Any(m => m is IMutableKeywordToken),
genericParameterTypes,
Lifetime.None);
declaration.Type.Fulfill(new Metatype(enumStructType));
break;
case EnumClassDeclarationSyntax enumStructDeclaration:
var enumClassType = new ObjectType(declaration,
enumStructDeclaration.Modifiers.Any(m => m is IMutableKeywordToken),
genericParameterTypes,
Lifetime.None);
declaration.Type.Fulfill(new Metatype(enumClassType));
break;
case TraitDeclarationSyntax declarationSyntax:
var type = new ObjectType(declaration,
declarationSyntax.Modifiers.Any(m => m is IMutableKeywordToken),
genericParameterTypes,
Lifetime.None);
declaration.Type.Fulfill(new Metatype(type));
break;
default:
throw NonExhaustiveMatchException.For(declaration);
}
}