I have a perl file where some functions are defined using special syntax (Mojolicious):
$app->helper('helper1' => sub {
print "Hello 1";
});
$app->helper("helper2" => sub {
print "Hello 2";
});
$app->helper(helper3 => sub {
print "Hello 3";
});
helper1();
helper2();
helper3();
I managed to create the Perl regexp to capture these definitions:
#!/usr/bin/perl
use strict;
use warnings;
use File::Slurp 'read_file';
my $code = read_file('helpers.pl');
my @matches = $code =~ /\$app\->helper\(['"]?(.*?)['"]? => sub/g;
foreach(@matches)
{
print "$_\n";
}
Output:
helper1
helper2
helper3
But my attempt to use it in etags failed;
etags -l perl --regex="/\$app\->helper\\\(['\"]\(.*?\)['\"] => sub/" ./helpers.pl
Gives an empty TAGS file. What's wrong?
CodePudding user response：
One of your problems is your shell escapes, eg:
"\$xxx"will end up being to$xxxwhich means EOL in regex."\-"will in a POSIX shell expand to\-.
You should use single quoted string to hold your pattern, as the only special character in single quotes are single quotes. If the pattern should be:
/\$app->helper\(['"](.*?)['"] => sub/
Then the single quote string would be:
'/\$app->helper\(['\''"](.*?)['\''"] => sub/'
I don't use exuberant-ctags, but Universal Ctags which is never. In Universal Ctags one would need to write:
/\$app->helper\(['"](.*)['"] => sub/\1/
Notice how the non-greedy modifier isn't supported, and how I provided the keyword creation part: \1/ after the pattern.
I'll leave it as an exercise to the reader to enclose the above pattern in single quotes.
CodePudding user response：
Universal Ctags just introduced pcre2 as an optional regular expression engine. If you build a ctags executable from the latest code in the git repository (git clone https://github.com/universal-ctags/ctags.git) with pcre2, you can use non-greedy match. That means the command line Andreas Louv showed may work well.
$ cat /tmp/foo.pl
$app->helper('helper1' => sub {
print "Hello 1";
});
$app->helper("helper2" => sub {
print "Hello 2";
});
$app->helper(helper3 => sub {
print "Hello 3";
});
helper1();
helper2();
helper3();
$ ./ctags -o - --regex-perl='/\$app->helper\(['\''"]?(.*?)['\''"]? => sub/\1/s/{pcre2}' /tmp/foo.pl
helper1 /tmp/foo.pl /^$app->helper('helper1' => sub {$/;" s
helper2 /tmp/foo.pl /^$app->helper("helper2" => sub {$/;" s
helper3 /tmp/foo.pl /^$app->helper(helper3 => sub {$/;" s
$ ./ctags -e --regex-perl='/\$app->helper\(['\''"]?(.*?)['\''"]? => sub/\1/s/{pcre2}' /tmp/foo.pl
$ cat TAGS
^L
/tmp/foo.pl,133
$app->helper('helper1' => sub {^?helper1^A1,0
$app->helper("helper2" => sub {^?helper2^A5,74
$app->helper(helper3 => sub {^?helper3^A9,148
$
You can verify you whether pcre2 is linked to your ctags or not.
$ ./ctags --list-features | grep pcre2
pcre2 has pcre2 regex engine
$