public void VisitBinOp(BinOp node)
{
if (node.Op.Type == TokenType.Assign)
{
var symbol = _symbols.Lookup(((Variable)node.Left).Name, true);
if (symbol == null)
{
throw new Exception($"Variable '{((Variable)node.Left).Name}' haven't been declared");
}
if (!(symbol is LetSymbol))
{
throw new Exception($"Cannot assign value to symbol of type {symbol.GetType()}");
}
}
else
{
Visit(node.Left);
}
Visit(node.Right);
}
public Symbol Lookup(string name, bool followParent = false)
{
return(!_symbols.ContainsKey(name) ? followParent ? _parent?.Lookup(name, true) : null : _symbols[name]);
}
