Keeping tags in regex

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Hello monks,

I am doing some substitutions of strings with a regex. For example, I have code like this:

%dictionary = (foo => 'bar',
               baz => 'w00t');

$str =~ s[$_][$dictionary{$_}] for keys %dictionary;
[download]

But now the problem is that some of the words have embedded XML tags. I would like to still perform the substition but keep the XML tag. There is at most one XML tag in a word; for example: <tag>f</tag>oo should become <tag>b</tag>ar

and

<b>fo</b>o should become <b>ba</b>r

Is there a simple way of doing this without writing out all of the possible combinations? Thanks!

Comment on Keeping tags in regex Select or Download Code

Replies are listed 'Best First'.
Re: Keeping tags in regex by choroba (Cardinal) on May 17, 2012 at 15:56 UTC
And what should happen to `b<tag>a</tag>z`?	[reply] [d/l]
Re^2: Keeping tags in regex by Anonymous Monk on May 17, 2012 at 17:05 UTC
The tags always sorround the first letter -- formatting the letter to be bold, italic, red, etc.	[reply]
Re: Keeping tags in regex by choroba (Cardinal) on May 17, 2012 at 22:51 UTC
#!/usr/bin/perl use warnings; use strict; my %dictionary = (foo => 'bar', baz => 'w00t'); sub replace { my $str = shift; $str =~ m[(<[^>]+>)?([^<]+)(</[^>]+>)?(.*)]; # the key should never contain '<' my $key = $2 . $4; my @tags = ($1, $3); my $length = length $2; $key =~ s[$_][$dictionary{$_}] for keys %dictionary; if (grep $_, @tags) { # return tags to replaced string substr $key, $length, 0, $tags[1]; substr $key, 0, 0, $tags[0]; } return $key; } use Test::More; is replace('baz'), 'w00t'; is replace('<tag>f</tag>oo'), '<tag>b</tag>ar'; is replace('<b>fo</b>o'), '<b>ba</b>r'; done_testing(); [download]	[reply] [d/l]
Re: Keeping tags in regex by afoken (Chancellor) on May 17, 2012 at 16:25 UTC
Looks like reg. expr. multiple substitutions, and especially Re: reg. expr. multiple substitutions ... Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply]
Re^2: Keeping tags in regex by Anonymous Monk on May 17, 2012 at 17:16 UTC
In the thred you link to, the discussion is over looping over the keys in a hash. Perhaps I didn't make myself clear in the question. I'm wondering if there's a way to extract the non-html out of the string, concatenate it, lookup the substitution in the hash, and then put the html back in. Something along the lines of: `s\|(\w)(<.+?>)(\w+)\|$dictionary{$1$3}\| if exists $dictionary{$1 . $3};` [download] but now I'm at a loss as to how to put the xml tag back in. I agree that if this is not possible, the alternative is to write all the combinations with the tags into the dictionary hash.	[reply] [d/l]