Re: How do I extract named variable names from regex string

Easy, you can let Perl do all the work. Assume your pattern is in $str, then do:

use 5.010;
"" =~ /(?:$str)?/;
while (my ($key, $matches) = each %-) {
    if (@$matches > 1) {
        say "Duplicate name $key";
    }
}
[download]

Comment on Re: How do I extract named variable names from regex string Download Code

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Re^2: How do I extract named variable names from regex string by LanX (Saint) on Jan 31, 2012 at 00:21 UTC
Sorry for nitpicking, but in praxis this only works with a string where all groups match, "" isn't enough. `use 5.010; "" =~ /(?<mon>\w+)\s(?<mon>\w+)/; print scalar keys %-; # 0` [download] Now constructing such a string is in general even more difficult than just parsing for named captures labels. Good idea anyway! :) Cheers Rolf	[reply] [d/l]
Re^3: How do I extract named variable names from regex string by JavaFan (Canon) on Jan 31, 2012 at 02:33 UTC
Thank you for playing, but you fail. `"" =~ /(?:(?<mon>\w+)\s(?<mon>\w+))?/; say scalar keys %-; # 1` [download] All that's required is for the pattern to match. Taking the pattern, and wrapping it inside a `(?: )?` will make it match against `""` (except for some degenerate cases). If you look back at my code, this is exactly what I did.	[reply] [d/l] [select]
Re^4: How do I extract named variable names from regex string by LanX (Saint) on Jan 31, 2012 at 03:47 UTC
Ups ... you're right! Cheers Rolf	[reply]