在键中使用特殊字符进行Perl哈希替换 [英] Perl hash substitution with special characters in keys

问题描述

我当前的脚本将带有一个表达式，例如:

My current script will take an expression, ex:

my $expression = '( a || b || c )';

并使用sub/replace遍历每个布尔输入组合，如下所示:

and go through each boolean combination of inputs using sub/replace, like so:

my $keys = join '|', keys %stimhash;
$expression =~ s/($keys)\b/$stimhash{$1}/g;

例如，表达式可以保存，

So for example expression may hold,

( 0 || 1 || 0 )

这很好.

但是，我想允许变量(也在％stimhash中)包含标记*.

However, I would like to allow the variables (also in %stimhash) to contain a tag, *.

my $expression = '( a* || b* || c* )';

此外，打印stimhash的键将返回:

Also, printing the keys of the stimhash returns:

a*|b*|c*

不能正确地用/替换特殊字符*.
它给出以下警告:

It is not properly substituting/replacing with the extra special character, *.
It gives this warning:

％stimhash中未初始化的值在替换迭代器中的使用

Use of uninitialized value within %stimhash in substitution iterator

我尝试使用quotemeta()，但到目前为止效果不佳.
它将删除这些值.替换后的示例如下:

I tried using quotemeta() but did not have good results so far.
It will drop the values. An example after the substitution looks like:

( * || * || * )

任何建议都值得赞赏，

约翰

推荐答案

问题1

您使用模式a*认为它仅与a*相匹配，但是a*表示"0或更多a".您可以使用quotemeta将文本转换为与该文本匹配的正则表达式模式.

Problem 1

You use the pattern a* thinking it will match only a*, but a* means "0 or more a". You can use quotemeta to convert text into a regex pattern that matches that text.

替换

my $keys = join '|', keys %stimhash;

使用

my $keys = join '|', map quotemeta, keys %stimhash;

问题2

\b

基本上是

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

但是*(如空格)不是文字字符.解决方法可能是替换

But * (like the space) isn't a word character. The solution might be to replace

s/($keys)\b/$stimhash{$1}/g

使用

s/($keys)(?![\w*])/$stimhash{$1}/g

尽管以下内容对我来说更有意义

though the following make more sense to me

s/(?<![\w*])($keys)(?![\w*])/$stimhash{$1}/g

我个人会用

s{([\w*]+)}{ $stimhash{$1} // $1 }eg

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