定义回文运算符，以后记中的相反顺序复制堆栈上的值

如何解决定义回文运算符，以后记中的相反顺序复制堆栈上的值

定义一个回文运算符，以相反的顺序复制堆栈上的值。

这是我到目前为止所拥有的，它没有按照我想要的去做

// will return true if *any* of the mentions were you if (message.mentions.users.has('Your ID')) return message.channel.send('Do not mention this user'); /palindrome { 1 dict begin count 1 gt { /first exch def /second exch def temp1 = first temp2 = last first = last last = temp1 }

解决方法

您在此编写的大部分内容在PostScript中都没有任何意义：

/palindrome
{
  1 dict begin
  count 1 gt 
  {
    /first exch def
    /second exch def
%% The following four lines are not valid PostScript
    temp1 = first
    temp2 = last
    first = last
    last = temp1
%% There is no '=' assignment operator in PostScript,in PS the = operator
%% pops one object from the stack and writes a text representation to stdout.
%% You have not defined any of the keys temp1,temp2 or last
%% in any dictionary. If executed I would expect this program to throw an
%% 'undefined' error in 'temp1'
  }
%% Given the 'count 1 gt' at the opening brace,I would expect this executable
%% array to be followed by a conditional,such as 'if'. Since it isn't this just
%% leaves the executable array '{....}' on the stack
} def

所以总的来说，我希望这个PostScript函数将布尔值推入操作数堆栈，是true还是false，这取决于堆栈在执行时是否有至少2个对象，然后是一个可执行数组。操作数堆栈并退出。

如果这样做，我会将堆栈存储到一个数组中，然后将该数组卸载回堆栈，然后从头到尾遍历该数组。像这样：

%!

/palindrome
{
  count array astore
  aload
  dup length 1 sub -1 0 {
   1 index exch get
    exch
  } for
  pop
} def

(line 1)
2
3

(before palindrome\n) print
pstack
palindrome
(after palindrome\n) print
pstack

通过使用for循环并操作堆栈，也可以一次通过（而不用定义任何额外的存储对象（字典或数组））来完成此操作（这里有一个有效的示例）。对于我来说，这似乎是一个更优雅的解决方案，留给读者练习：-）