如何删除PHP中单引号之间的所有空格，跳过转义引号

Question

正如标题所问的：

如何在PHP中删除所有不必要的单引号之间的空格，跳过转义引号？

我正在寻找一个快速的实现来为解析做准备。如果正则表达式比使用简单的循环慢，我不喜欢使用正则表达式。

(下面的双引号仅用于显示)

示例如下：

输入：

"    testing    '  this  is a     \'test\'  '     zzz     "

输出：

"testing '  this  is a     \'test\'  ' zzz"

Answer 1

<?php

$parts = preg_split('/((?<!\\\\)|(?<=\\\\\\\\))\'/', trim($data));

foreach ($parts as $index => &$part) {
    if ($index % 2 == 0) {
        $part = preg_replace('/\s{2,}/', ' ', $part);
    }
}

echo join('\'', $parts);

现在等待我错过的更简单的解决方案:p

Answer 2

好了，psuedocode时间：

var shouldtrim = true;
var escaped = false;
foreach char in string
    if char is whitespace and lastchar is whitespace and shouldtrim
        remove char from string

    if char is ' and not escaped
        toggle shouldtrim

    if char is \
        toggle escaped
    else
        escaped = false

Answer 3

试试这个：

<?php
$str = "    testing    '  this  is a     \'test\'  '     zzz     ";

echo trim($str," ");

?>