Since you're just doing it for fun, here's an alternate way. Just change comma to dashes where needed and clean up the runs later :) 

#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11162490
use warnings;

for ( split /^/, <<END )
Attacca Quartet:1,2,3,4,5,6,7,8,10,11,12,13,14,15,16,17,18,19,20,22,23
+,24,25,26,27,28
John Patitucci:1,2,3,5,8,11,12,13,14,15,16,17,19,25,26,27,28
Roomful of Teeth:1,3,5,7,9,12,14,16,19,21,24,26,28
S&#333; Percussion:1,3,4,5,6,7,8,11,12,13,14,15,16,18,19,21,22,23,24,2
+5,26,27,28
Has Dashes:1,3-6,7-9,11,13-20,21,22-25,30,33-34,351,520
END
  {
  print "\n$_";
  print s/\b(\d+)\K,(?=(??{$1+1})\b)/-/gr =~ s/-[\d-]*-/-/gr;
  }

[download]

Outputs:


Attacca Quartet:1,2,3,4,5,6,7,8,10,11,12,13,14,15,16,17,18,19,20,22,23
+,24,25,26,27,28
Attacca Quartet:1-8,10-20,22-28

John Patitucci:1,2,3,5,8,11,12,13,14,15,16,17,19,25,26,27,28
John Patitucci:1-3,5,8,11-17,19,25-28

Roomful of Teeth:1,3,5,7,9,12,14,16,19,21,24,26,28
Roomful of Teeth:1,3,5,7,9,12,14,16,19,21,24,26,28

S&#333; Percussion:1,3,4,5,6,7,8,11,12,13,14,15,16,18,19,21,22,23,24,2
+5,26,27,28
S&#333; Percussion:1,3-8,11-16,18-19,21-28

Has Dashes:1,3-6,7-9,11,13-20,21,22-25,30,33-34,351,520
Has Dashes:1,3-9,11,13-25,30,33-34,351,520

[download]

In reply to Re: Consolidate ranges (quick and dirty with a cool regexp) by tybalt89
in thread Consolidate ranges (quick and dirty with a cool regexp) by gpvos

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