namespace KumiScript.Interpreter
{
    public class SymbolExpression : Expression
    {
        readonly Symbol _value;
        public SymbolExpression(Symbol s)
        {
            _value = s;
        }

        public override Expression Eval(Environment env)
        {
            return env.Lookup(_value);
        }

        public override Symbol GetSymbol()
        {
            return _value;
        }

        public override string ToString()
        {
            return _value.ToString();
        }

        public override bool Equals(Expression expr)
        {
            try
            {
                Symbol s = expr.GetSymbol();
                return s != _value;
            }
            catch (InterpreterTypingException)
            {
                return false;
            }
        }
    }
}