public object visitUnaryExpr(Expr.Unary expr)
{
object right = evaluate(expr.right);
switch (expr.operator_.type)
{
case TokenType.BANG:
return(!isTruthy(right));
case TokenType.MINUS:
checkNumberOperand(expr.operator_, right);
return(-(double)right);
}
return(null);
}
public string visitUnaryExpr(Expr.Unary expr)
{
return(parenthesize(expr.operator_.lexeme, expr.right));
}
public object visitUnaryExpr(Expr.Unary expr)
{
resolve(expr.right);
return(null);
}