public object VisitUnaryExpr(Expr.Unary expr)
{
var right = Evaluate(expr.Right);
switch (expr.Operator.Type)
{
case TokenType.Minus:
CheckNumberOperand(expr.Operator, right);
return(-(double)right);
case TokenType.Bang:
return(!IsTruthy(right));
}
return(null);
}
public string VisitUnaryExpr(Expr.Unary expr)
{
return($"{expr.Operator}{expr.Right.Accept(this)}");
}
public string VisitUnaryExpr(Expr.Unary expr)
{
return(Parenthesize(expr.Operator.Lexeme, expr.Right));
}