Re: Array Filter and Lookahead

[moritz]

If you really want the last integer in a string, you can find that as /.*(?<!\d)(\d+)/, and get the numbers as

my @filtered = map { /.*(?<!\d)(\d+)/; $1 // '' } @lines;

However you seem to want to turn 3.0 into 3 (and not 0), and I don't know the rules behind that. Do you want to permit decimals, and cut off zero-decimals behind the dot? Or something else?

[AnomalousMonk]

>perl -wMstrict -le
"my @lines = ('xx',  '0 xx',  '1 xx 3.2');
 ;;
 'Zonk' =~ m{ (\w+) }xms;
 ;;
 my @filtered = map { /.*(?<!\d)(\d+)/; $1 // '' } @lines;
 printf qq{'$_' } for @filtered;
"
'Zonk' '0' '2'

[moritz]

Right, I forget about Perl 5's insane behavior about capture variables when a match failed. The correct way would be to use /.../ and $1 // '' or some variation thereof.

[daugh016]

Thanks for the feedback! The numbers are actually section numbers so sometimes they are written "section 1" and sometimes it could be "section 1.", "section 1)", "section 1.)", etc.

[AnomalousMonk]

So what's the extraction rule? One can make a guess based on the examples just given, but an explicit definition is always nice to have.