internal static bool CheckReturnType(PastelCompiler compiler, PType returnType, PType value)
{
// This is an assert, not a user-facing exception. Null should never appear here.
if (value == null)
{
throw new ParserException(returnType.FirstToken, "This should not happen.");
}
if (value.IsIdenticalOrChildOf(compiler, returnType))
{
return(true);
}
if (returnType.Category == TypeCategory.OBJECT)
{
return(true);
}
if (returnType.Category == TypeCategory.VOID)
{
return(false);
}
if (value.Category == TypeCategory.NULL)
{
if (returnType.Category == TypeCategory.PRIMITIVE && returnType.TypeName == "string")
{
return(true);
}
if (returnType.Generics.Length > 0)
{
return(true);
}
if (returnType.IsStructOrClass)
{
return(true);
}
}
return(false);
}
// when a templated type coincides with an actual value, add that template key to the lookup output param.
internal static bool CheckAssignmentWithTemplateOutput(PastelCompiler compiler, PType templatedType, PType actualValue, Dictionary <string, PType> output)
{
if (templatedType.Category == TypeCategory.OBJECT)
{
return(true);
}
// Most cases, nothing to do
if (templatedType.IsIdenticalOrChildOf(compiler, actualValue))
{
return(true);
}
if (templatedType.RootValue.Length == 1)
{
if (output.ContainsKey(templatedType.RootValue))
{
PType requiredType = output[templatedType.RootValue];
// if it's already encountered it better match the existing value
if (actualValue.IsIdenticalOrChildOf(compiler, requiredType))
{
return(true);
}
// It's also possible that this is null, in which case the type must be nullable.
if (actualValue.Category == TypeCategory.NULL && requiredType.IsNullable)
{
return(true);
}
return(false);
}
output[templatedType.RootValue] = actualValue;
return(true);
}
if (templatedType.Generics.Length != actualValue.Generics.Length)
{
// completely different. don't even try to match templates
return(false);
}
if (templatedType.RootValue != actualValue.RootValue)
{
if (templatedType.RootValue.Length == 1)
{
if (output.ContainsKey(templatedType.RootValue))
{
// if it's already encountered it better match the existing value
if (actualValue.IsIdentical(compiler, output[templatedType.RootValue]))
{
// yup, that's okay
}
else
{
return(false);
}
}
else
{
// first time this type was encountered.
output[templatedType.RootValue] = actualValue;
}
}
else
{
// different type
return(false);
}
}
for (int i = 0; i < templatedType.Generics.Length; ++i)
{
if (!CheckAssignmentWithTemplateOutput(compiler, templatedType.Generics[i], actualValue.Generics[i], output))
{
return(false);
}
}
return(true);
}