http://www.perlmonks.org?node_id=45046


in reply to Yet another Algorithm::Diff question

here it is again in forward order, with deletions and additions processed in a single pass:
#!/usr/bin/perl -w use Data::Dumper; use Algorithm::Diff qw(diff); use strict; use subs qw(patch); ## ## sub patch { my @orig = @{shift()}; my $diff = shift; my $shift = 0; for my $hunk (@$diff) { for my $change (@$hunk) { if ($change->[0] eq "-") { # process deletions splice @orig, $change->[1] + $shift, 1; --$shift; } elsif ($change->[0] eq "+") { # process additions splice @orig, $change->[1], 0, $change->[2]; ++$shift; } } } @orig; } ## ## my @orig = qw(a b c e h j l m n p); my @rev = qw(b c d e f j k l m r s t); my $diff = diff \@orig, \@rev; my @patched = patch \@orig, $diff; print "Original:\t@orig", $/; print "Revision:\t@rev", $/; print "Patched:\t@patched", $/;