Re^2: qr for recursive regex?

[darisler]

The example I posted is simplified - perhaps too much.

I really want repetition, not recursion, but ran into roadblock with perl behaviour of only returning the last matches. Here is what I first tried, it only returns the last coordinate pair, which is documented behaviour.

#!/usr/bin/env perl

use v5.16;
use strict;


my $prBoundaryString = <<endPrBoundary;
'( (0.01 0.02) (0.0 1328.23) (0.03 0.04) )
endPrBoundary

say "prBoundaryString=$prBoundaryString";

   my ($coord,$coords);

   $coord = qr{
      \(\s*
         (?<x>[\-\.0-9]+)\s+ 
         (?<y>[\-\.0-9]+)\s*
      \)\s*
   }x;

   $coords = qr{
   (
      ( $coord )+
   )
   }x;

   $prBoundaryString =~ m{
       \'\(\s*\s*
       $coords
       \)\s*$
   }x || die "parsePrBoundary: Error parsing prBoundary";

   say "-x0=$-{x}[0]";
   say "-y0=$-{y}[0]";
   say "-x1=$-{x}[1]";
   say "-y1=$-{y}[1]";
   say "-x2=$-{x}[2]";
   say "-y2=$-{y}[2]";

output: - it only gets the last coordinate.

prBoundaryString='( (0.01 0.02) (0.0 1328.23) (0.03 0.04) )

-x0=0.03
-y0=0.04
-x1=
-y1=
-x2=
-y2=

[Limbic~Region]

darisler,
If you use a regex with the global modifier in scalar context, you will get an iterator allowing you to go through each set of matches one at a time (like one of the examples above):

while ($str =~ m{$your_regex}g) {
    my ($x, $y) = ($1, $2);
    # This loop will repeat for as many matches as are in $str
}