为什么下面的代码会在字符类中给出＆＃39; Range乱序？＆＃39;错误？
var min_wordsafe_length = 1;
var max_length = 20;
var string = 'some-slug-like-string-with-!@£!%-special-chars-';
var PREG_CLASS_UNICODE_WORD_BOUNDARY = [
'\\x{0}-\\x{2F}\\x{3A}-\\x{40}\\x{5B}-\\x{60}\\x{7B}-\\x{A9}\\x{AB}-\\x{B1}\\x{B4}',
'\\x{B6}-\\x{B8}\\x{BB}\\x{BF}\\x{D7}\\x{F7}\\x{2C2}-\\x{2C5}\\x{2D2}-\\x{2DF}',
'\\x{2E5}-\\x{2EB}\\x{2ED}\\x{2EF}-\\x{2FF}\\x{375}\\x{37E}-\\x{385}\\x{387}\\x{3F6}',
'\\x{482}\\x{55A}-\\x{55F}\\x{589}-\\x{58A}\\x{5BE}\\x{5C0}\\x{5C3}\\x{5C6}',
'\\x{5F3}-\\x{60F}\\x{61B}-\\x{61F}\\x{66A}-\\x{66D}\\x{6D4}\\x{6DD}\\x{6E9}',
'\\x{6FD}-\\x{6FE}\\x{700}-\\x{70F}\\x{7F6}-\\x{7F9}\\x{830}-\\x{83E}',
'\\x{964}-\\x{965}\\x{970}\\x{9F2}-\\x{9F3}\\x{9FA}-\\x{9FB}\\x{AF1}\\x{B70}',
'\\x{BF3}-\\x{BFA}\\x{C7F}\\x{CF1}-\\x{CF2}\\x{D79}\\x{DF4}\\x{E3F}\\x{E4F}',
'\\x{E5A}-\\x{E5B}\\x{F01}-\\x{F17}\\x{F1A}-\\x{F1F}\\x{F34}\\x{F36}\\x{F38}',
'\\x{F3A}-\\x{F3D}\\x{F85}\\x{FBE}-\\x{FC5}\\x{FC7}-\\x{FD8}\\x{104A}-\\x{104F}',
'\\x{109E}-\\x{109F}\\x{10FB}\\x{1360}-\\x{1368}\\x{1390}-\\x{1399}\\x{1400}',
'\\x{166D}-\\x{166E}\\x{1680}\\x{169B}-\\x{169C}\\x{16EB}-\\x{16ED}',
'\\x{1735}-\\x{1736}\\x{17B4}-\\x{17B5}\\x{17D4}-\\x{17D6}\\x{17D8}-\\x{17DB}',
'\\x{1800}-\\x{180A}\\x{180E}\\x{1940}-\\x{1945}\\x{19DE}-\\x{19FF}',
'\\x{1A1E}-\\x{1A1F}\\x{1AA0}-\\x{1AA6}\\x{1AA8}-\\x{1AAD}\\x{1B5A}-\\x{1B6A}',
'\\x{1B74}-\\x{1B7C}\\x{1C3B}-\\x{1C3F}\\x{1C7E}-\\x{1C7F}\\x{1CD3}\\x{1FBD}',
'\\x{1FBF}-\\x{1FC1}\\x{1FCD}-\\x{1FCF}\\x{1FDD}-\\x{1FDF}\\x{1FED}-\\x{1FEF}',
'\\x{1FFD}-\\x{206F}\\x{207A}-\\x{207E}\\x{208A}-\\x{208E}\\x{20A0}-\\x{20B8}',
'\\x{2100}-\\x{2101}\\x{2103}-\\x{2106}\\x{2108}-\\x{2109}\\x{2114}',
'\\x{2116}-\\x{2118}\\x{211E}-\\x{2123}\\x{2125}\\x{2127}\\x{2129}\\x{212E}',
'\\x{213A}-\\x{213B}\\x{2140}-\\x{2144}\\x{214A}-\\x{214D}\\x{214F}',
'\\x{2190}-\\x{244A}\\x{249C}-\\x{24E9}\\x{2500}-\\x{2775}\\x{2794}-\\x{2B59}',
'\\x{2CE5}-\\x{2CEA}\\x{2CF9}-\\x{2CFC}\\x{2CFE}-\\x{2CFF}\\x{2E00}-\\x{2E2E}',
'\\x{2E30}-\\x{3004}\\x{3008}-\\x{3020}\\x{3030}\\x{3036}-\\x{3037}',
'\\x{303D}-\\x{303F}\\x{309B}-\\x{309C}\\x{30A0}\\x{30FB}\\x{3190}-\\x{3191}',
'\\x{3196}-\\x{319F}\\x{31C0}-\\x{31E3}\\x{3200}-\\x{321E}\\x{322A}-\\x{3250}',
'\\x{3260}-\\x{327F}\\x{328A}-\\x{32B0}\\x{32C0}-\\x{33FF}\\x{4DC0}-\\x{4DFF}',
'\\x{A490}-\\x{A4C6}\\x{A4FE}-\\x{A4FF}\\x{A60D}-\\x{A60F}\\x{A673}\\x{A67E}',
'\\x{A6F2}-\\x{A716}\\x{A720}-\\x{A721}\\x{A789}-\\x{A78A}\\x{A828}-\\x{A82B}',
'\\x{A836}-\\x{A839}\\x{A874}-\\x{A877}\\x{A8CE}-\\x{A8CF}\\x{A8F8}-\\x{A8FA}',
'\\x{A92E}-\\x{A92F}\\x{A95F}\\x{A9C1}-\\x{A9CD}\\x{A9DE}-\\x{A9DF}',
'\\x{AA5C}-\\x{AA5F}\\x{AA77}-\\x{AA79}\\x{AADE}-\\x{AADF}\\x{ABEB}',
'\\x{E000}-\\x{F8FF}\\x{FB29}\\x{FD3E}-\\x{FD3F}\\x{FDFC}-\\x{FDFD}',
'\\x{FE10}-\\x{FE19}\\x{FE30}-\\x{FE6B}\\x{FEFF}-\\x{FF0F}\\x{FF1A}-\\x{FF20}',
'\\x{FF3B}-\\x{FF40}\\x{FF5B}-\\x{FF65}\\x{FFE0}-\\x{FFFD}'].join('');
new RegExp("^(.{" + min_wordsafe_length + ","+ max_length +"})[" + PREG_CLASS_UNICODE_WORD_BOUNDARY + "]");
错误似乎与PREG_CLASS_UNICODE_WORD_BOUNDARY有关，但我无法解决范围无序的问题。
我试图将Drupal的truncate_utf8函数中的以下行移植到JavaScript：
// Find the last word boundary, if there is one within $min_wordsafe_length
// to $max_length characters. preg_match() is always greedy, so it will
// find the longest string possible.
$found = preg_match('/^(.{' . $min_wordsafe_length . ',' . $max_length . '})[' . PREG_CLASS_UNICODE_WORD_BOUNDARY . ']/u', $string, $matches);
我在JavaScript中对Drupal PREG_CLASS_UNICODE_WORD_BOUNDARY所做的唯一更改是双重逃避\x以防止\在正则表达式之前丢失，并用数组连接替换PHP的字符串连接。我没有做任何改变范围顺序的事情。
如何修复此代码？我需要JavaScript正则表达式尽可能地匹配PHP正则表达式的行为。
答案 0 :(得分：3)
JavaScript使用语法\uhhhh（正好4个十六进制数字）来指定正则表达式中的UTF-16代码单元。对于BMP范围内的字符，除了范围D800-DFFF之外，字符的代码点直接映射到一个具有相同代码点值的UTF-16代码单元。这就是这里的情况，所以我们不需要处理代理及其怪癖。
在这种情况下，只需用\x{h...hh}语法从PCRE（在PHP中）替换\uhhhh语法：
var PREG_CLASS_UNICODE_WORD_BOUNDARY = [
"\\u0000-\\u002F\\u003A-\\u0040\\u005B-\\u0060\\u007B-\\u00A9\\u00AB-\\u00B1\\u00B4",
"\\u00B6-\\u00B8\\u00BB\\u00BF\\u00D7\\u00F7\\u02C2-\\u02C5\\u02D2-\\u02DF",
"\\u02E5-\\u02EB\\u02ED\\u02EF-\\u02FF\\u0375\\u037E-\\u0385\\u0387\\u03F6",
"\\u0482\\u055A-\\u055F\\u0589-\\u058A\\u05BE\\u05C0\\u05C3\\u05C6",
"\\u05F3-\\u060F\\u061B-\\u061F\\u066A-\\u066D\\u06D4\\u06DD\\u06E9",
"\\u06FD-\\u06FE\\u0700-\\u070F\\u07F6-\\u07F9\\u0830-\\u083E",
"\\u0964-\\u0965\\u0970\\u09F2-\\u09F3\\u09FA-\\u09FB\\u0AF1\\u0B70",
"\\u0BF3-\\u0BFA\\u0C7F\\u0CF1-\\u0CF2\\u0D79\\u0DF4\\u0E3F\\u0E4F",
"\\u0E5A-\\u0E5B\\u0F01-\\u0F17\\u0F1A-\\u0F1F\\u0F34\\u0F36\\u0F38",
"\\u0F3A-\\u0F3D\\u0F85\\u0FBE-\\u0FC5\\u0FC7-\\u0FD8\\u104A-\\u104F",
"\\u109E-\\u109F\\u10FB\\u1360-\\u1368\\u1390-\\u1399\\u1400",
"\\u166D-\\u166E\\u1680\\u169B-\\u169C\\u16EB-\\u16ED",
"\\u1735-\\u1736\\u17B4-\\u17B5\\u17D4-\\u17D6\\u17D8-\\u17DB",
"\\u1800-\\u180A\\u180E\\u1940-\\u1945\\u19DE-\\u19FF",
"\\u1A1E-\\u1A1F\\u1AA0-\\u1AA6\\u1AA8-\\u1AAD\\u1B5A-\\u1B6A",
"\\u1B74-\\u1B7C\\u1C3B-\\u1C3F\\u1C7E-\\u1C7F\\u1CD3\\u1FBD",
"\\u1FBF-\\u1FC1\\u1FCD-\\u1FCF\\u1FDD-\\u1FDF\\u1FED-\\u1FEF",
"\\u1FFD-\\u206F\\u207A-\\u207E\\u208A-\\u208E\\u20A0-\\u20B8",
"\\u2100-\\u2101\\u2103-\\u2106\\u2108-\\u2109\\u2114",
"\\u2116-\\u2118\\u211E-\\u2123\\u2125\\u2127\\u2129\\u212E",
"\\u213A-\\u213B\\u2140-\\u2144\\u214A-\\u214D\\u214F",
"\\u2190-\\u244A\\u249C-\\u24E9\\u2500-\\u2775\\u2794-\\u2B59",
"\\u2CE5-\\u2CEA\\u2CF9-\\u2CFC\\u2CFE-\\u2CFF\\u2E00-\\u2E2E",
"\\u2E30-\\u3004\\u3008-\\u3020\\u3030\\u3036-\\u3037",
"\\u303D-\\u303F\\u309B-\\u309C\\u30A0\\u30FB\\u3190-\\u3191",
"\\u3196-\\u319F\\u31C0-\\u31E3\\u3200-\\u321E\\u322A-\\u3250",
"\\u3260-\\u327F\\u328A-\\u32B0\\u32C0-\\u33FF\\u4DC0-\\u4DFF",
"\\uA490-\\uA4C6\\uA4FE-\\uA4FF\\uA60D-\\uA60F\\uA673\\uA67E",
"\\uA6F2-\\uA716\\uA720-\\uA721\\uA789-\\uA78A\\uA828-\\uA82B",
"\\uA836-\\uA839\\uA874-\\uA877\\uA8CE-\\uA8CF\\uA8F8-\\uA8FA",
"\\uA92E-\\uA92F\\uA95F\\uA9C1-\\uA9CD\\uA9DE-\\uA9DF",
"\\uAA5C-\\uAA5F\\uAA77-\\uAA79\\uAADE-\\uAADF\\uABEB",
"\\uE000-\\uF8FF\\uFB29\\uFD3E-\\uFD3F\\uFDFC-\\uFDFD",
"\\uFE10-\\uFE19\\uFE30-\\uFE6B\\uFEFF-\\uFF0F\\uFF1A-\\uFF20",
"\\uFF3B-\\uFF40\\uFF5B-\\uFF65\\uFFE0-\\uFFFD"].join('');