Win8 Strawberry 5.30.3.1 (64) Sat 09/11/2021 21:56:27 C:\@Work\Perl\monks >perl use strict; use warnings; # 1 2 3 4 5 6 7 # 01234567890123456789012345678901234567890123456789012345678901234567890123456789 my $string = 'hello my * name is Rob * and * I am a very nice person * at least * I think * so'; my @Tests_ok = ( [ 30, # offset associated with '* ' sequence in split $string, # string to split into 2 parts 'hello my * name is Rob * and *', # part 1 of split 'I am a very nice person * at least * I think * so', # part 2 ], [ 29, $string, 'hello my * name is Rob * and *', 'I am a very nice person * at least * I think * so', ], [ 31, $string, 'hello my * name is Rob * and *', 'I am a very nice person * at least * I think * so', ], [ 9, $string, 'hello my *', 'name is Rob * and * I am a very nice person * at least * I think * so', ], [ 40, $string, 'hello my * name is Rob * and *', 'I am a very nice person * at least * I think * so', ], [ 28, $string, 'hello my * name is Rob *', 'and * I am a very nice person * at least * I think * so', ], [ 60, $string, 'hello my * name is Rob * and * I am a very nice person *', 'at least * I think * so', ], [ 79, $string, 'hello my * name is Rob * and * I am a very nice person * at least * I think *', 'so', ], [ 999, $string, 'hello my * name is Rob * and * I am a very nice person * at least * I think *', 'so', ], ); # end @Tests_ok my @Tests_fail = ( # all these tests should fail [ 0, # only fails because {-1} quantifier does not compile meaningfully $string, 'hello my * name is Rob * and *', 'I am a very nice person * at least * I think * so', ], [ 28, $string, 'hello my * name is Rob * and *', 'I am a very nice person * at least * I think * so', ], [ 55, $string, 'hello my * name is Rob * and *', 'I am a very nice person * at least * I think * so', ], ); # end @Tests_fail sub split_before { # modified from choroba pm#11136667 my ($string, $pos) = @_; # print "=== A: \$pos $pos \n"; # for debug $pos = rindex $string, '*', $pos; # print "=== B: \$pos $pos \n"; # for debug split /(?<=^.{$pos}\*) /, $string, 2 } use Test2::V0; VECTOR_ok: for my $ar_vector (@Tests_ok) { my ($position, $str, $part1, $part2) = @$ar_vector; die "'$part1' '$part2' test data invalid" unless "$part1 $part2" eq $str; is [split_before($str, $position)], [$part1, $part2], "$position split is valid"; } # end for VECTOR_ok note "\n=== all following tests expected to fail ===\n\n"; VECTOR_fail: for my $ar_vector (@Tests_fail) { my ($position, $str, $part1, $part2) = @$ar_vector; die "'$part1' '$part2' test data invalid" unless "$part1 $part2" eq $str; isnt [split_before($str, $position)], [$part1, $part2], "$position split invalid"; } # end for VECTOR_fail done_testing(); ^Z # Seeded srand with seed '20210911' from local date. ok 1 - 30 split is valid ok 2 - 29 split is valid ok 3 - 31 split is valid ok 4 - 9 split is valid ok 5 - 40 split is valid ok 6 - 28 split is valid ok 7 - 60 split is valid ok 8 - 79 split is valid ok 9 - 999 split is valid # # === all following tests expected to fail === # Unescaped left brace in regex is passed through in regex; marked by <-- HERE in m/(?<=^.{ <-- HERE -1}\*) / at - line 93. ok 10 - 0 split invalid ok 11 - 28 split invalid ok 12 - 55 split invalid 1..12