public ParseContext Parse(IParseTree context, LexicalEnvironment parentEnvironment)
{
parseContext = new ParseContext(_engine, parentEnvironment);
if (_scriptFunction != null)
{
foreach (var kv in parentEnvironment.Variables)
{
parseContext.AddVariableReference(kv.Value, VariableReferenceType.Argument);
}
}
Visit(context);
parseContext.LexicalEnvironment = parseContext.LexicalEnvironment.Root;
return(parseContext);
}
public override ParseResult VisitVariableDefinitionStatement(MelonParser.VariableDefinitionStatementContext context)
{
var expressionResult = Visit(context.expression());
MelonType type;
int typeId;
TypeReference typeReference = null;
if (context.Type != null)
{
var typeName = context.Type.name().value;
var typeKv = _engine.Types.FirstOrDefault(x => x.Value.Name == typeName);
if (typeKv.Value == null)
{
throw new MelonException($"Could not find type '{typeName}'");
}
if (typeKv.Value == _engine.voidType)
{
throw new MelonException($"Cannot assign to void");
}
if (expressionResult.typeReference.TypeId != typeKv.Key && typeKv.Key != 0)
{
throw new MelonException($"Variable of type '{typeName}' can't be assigned to '{expressionResult.typeReference.Type.Name}'");
}
typeReference = CreateTypeReference(context.Type);
type = typeKv.Value;
typeId = typeKv.Key;
}
else
{
type = expressionResult.typeReference.Type;
typeReference = new TypeReference(_engine, type);
if (type == _engine.voidType)
{
throw new MelonException($"Cannot assign to void");
}
typeId = expressionResult.typeReference.TypeId;
}
var name = context.Name.value;
var variable = parseContext.LexicalEnvironment.GetVariable(name);
int id;
if (expressionResult.value is IGeneric generic)
{
generic.GenericTypes = typeReference.GenericTypes;
}
if (variable != null)
{
throw new MelonException($"Variable '{name}' already defined.");
}
else
{
variable = parseContext.LexicalEnvironment.AddVariable(name, expressionResult.value, typeReference);
id = parseContext.AddVariableReference(variable, VariableReferenceType.Local);
}
parseContext.instructions.Add((int)OpCode.STLOC);
parseContext.instructions.Add(id);
instructionline++;
return(DefaultResult);
}
