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Re^2: Match last word in a sentence

by eyepopslikeamosquito (Bishop)
on Aug 14, 2021 at 00:06 UTC ( #11135834=note: print w/replies, xml ) Need Help??


in reply to Re: Match last word in a sentence
in thread Match last word in a sentence

This appears to contain a bug, revealed when you change the print lines as shown below:

use strict; use warnings; my $list = "This is my list"; $list =~ / ^(.+) # The 'rest' (Everything before last word) (\w+) # Last 'word' (string of contiguous word characters) \W*$ # Possible non-word characters at end of string /x; my $last = $2; my $the_rest = $1; print "the_rest='$the_rest'\n"; print "last='$last'\n";
Running this produces:
the_rest='This is my lis' last='t'

There are many ways to fix. Here is one way (adding a \b assertion):

$list =~ / ^(.+) # The 'rest' (Everything before last word) \b(\w+) # Last 'word' (string of contiguous word characters) \W*$ # Possible non-word characters at end of string /x;

Alternative fixes welcome.

Replies are listed 'Best First'.
Re^3: Match last word in a sentence
by parv (Vicar) on Aug 14, 2021 at 01:39 UTC

    Is making the first part non-greedy not enough ...

    my $list = "This is my list"; $list =~ m/^(.+?) # The 'rest' (Everything before last word) (\w+) # Last 'word' (string of contiguous word character +s) \W*$ # Possible non-word characters at end of string /x;

    ... (would it fail on some other string)?

    Much later. For English language, \w is not inclusive enough (lacks hyphen) and includes too much (includes underscore & digits). Short of a proper grammar based parser, I would rather use word regex which addresses that ...

    $word_re = qr{ (?: & | -? [a-zA-Z]+ [a-zA-Z-]* ) }x;

    ... is still incomplete as it does not deal with accented characters; periods in a title; acronyms with spaces and/or periods, among other things.

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