正则表达式匹配以特殊字符开头的单词边界 [英] regex to match word boundary beginning with special characters

问题描述

我有正则表达式可以匹配单词，除非它们包含特殊字符，例如 〜Query，这是C ++类的成员的名称. 对于单个字符的成员名称，需要使用如下所示的单词边界. $key =~ /\b$match\b/

I have regex that matches words fine except if they contain a special character such as ~Query which is the name of a member of a C++ class. Need to use word boundary as shown below for member names that are single characters. $key =~ /\b$match\b/

我尝试了很多我认为可以使用的表达式，例如/[~]*\b$match\b/或/\b[~]*$match\b/

I tried numerous expressions I thought would work such as /[~]*\b$match\b/ or /\b[~]*$match\b/

是否可以在可能包含特殊字符的单词上设置单词边界?

Is it possible to put a word boundary on words that may contain a special character?

推荐答案

\b

是

(?:(?<!\w)(?=\w)|(?<=\w)(?!\w))

如果要将~视为单词字符，请将\w更改为[\w~].

If you want to treat ~ as a word character, change \w to [\w~].

(?:(?<![\w~])(?=[\w~])|(?<=[\w~])(?![\w~]))

示例用法:

my $word_char = qr/[\w~]/;
my $boundary  = qr/(?<!$word_char)(?=$word_char)
                  |(?<=$word_char)(?!$word_char)/x;

$key =~ /$boundary$match$boundary/

如果我们知道$match只能匹配以$word_char开头和结尾的内容，则可以简化如下:

If we know $match can only match something that starts and ends with a $word_char, we can simplify as follows:

my $word_char   = qr/[\w~]/;
my $start_bound = qr/(?<!$word_char)/;
my $end_bound   = qr/(?!$word_char)/;

$key =~ /$start_bound$match$end_bound/

这很简单，我们可以内联.

This is simple enough that we can inline.

$key =~ /(?<![\w~])$match(?![\w~])/

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