Dear Monks, Trying to write some code that reads in a list of coordinates, must have an odd number for some odd reason. Here is some working code; but I'd like to know how to define '$coords' recursively, so it would work for any number of coordinates. Also, how do I check how many coordinates I have, when all done? 
#!/usr/bin/env perl

use v5.16;
use strict;


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

say "prBoundaryString=$prBoundaryString";

   my ($coord,$coords);

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

   $coords = qr{
   (
      $coord
      $coord
      $coord
   ) | (
      $coord
      $coord
      $coord
      $coord
      $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]";

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In reply to qr for recursive regex? by darisler

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