Algorithm::Diff3 - compute three way differnces between text.

NAME

Algorithm::Diff3 - compute three way differnces between text.

SYNOPSYS

  use Algorithm::Diff3;
  my $f = Algorithm::Diff3::Factory->new;
  my $mytext   = $f->create_text([ map{chomp;$_} <F0> ]);
  my $mytext   = $f->create_text( $string );
  my $original = $f->create_text([ map{chomp;$_} <F1> ]);
  my $yourtext = $f->create_text([ map{chomp;$_} <F2> ]);
  my $p = $f->create_diff3;
  my $diff3 = $p->diff3( $mytext, $origial, $yourtext );
  $diff3->each(sub{
      my( $r ) = @_;
      print $r->as_string, "\n";
      print $mytext->as_string_at( $_ ) for $r->range0;
      print $original->as_string_at( $_ ) for $r->range2;
      print $yourtext->as_string_at( $_ ) for $r->range1;
  });

ABSTRACT

This is a Perl module to compute differnce sets between three text buffers ported from GNU diff3.c written by Randy Smith.

DESCRIPTION

The three way diff procedure (diff3) might be required building an application to arbitrate manipulations under concurrent works. This diff3 code into Perl language has ported from GNU diff3.c widely used.

create

Author recommends you to create an instanse of diff prosessor by using with a factory as follows.

  use SomeFactory;
  my $f = SomeFactory->new;
  my $p = $f->create_diff3;

Algorithm::Diff3::Factory is a class to packaging several classes for the buildin diff processor.

diff3

Performing the diff3 process, we send a `diff3' message with three text instanses to the receiver

  my $diff3 = $p->diff3( $mytest, $origial, $yourtext );

Where the parameters of text might be a kind of as follows.

After the process, the receiver returns the list as difference sets.

  case $range3->type
  when 0: changes occured in mytext ($text0).
  when 1: changes occured in yourtext ($text1).
  when 2: changes occured in original ($text2).
  when 'A': confict!
  end

Additionally, GNU diff3.c treats as conflict when delete same lines both mytext and yourtext (why?).

SEE ALSO

GNU/diffutils/2.7/diff3.c

   Three way file comparison program (diff3) for Project GNU.
   Copyright (C) 1988, 1989, 1992, 1993, 1994 Free Software Foundation, Inc.
   Written by Randy Smith

P. Heckel. ``A technique for isolating differences between files.'' Communications of the ACM, Vol. 21, No. 4, page 264, April 1978.

AUTHOR

MIZUTANI Tociyuki <tociyuki@gmail.com>

COPYRIGHT AND LICENSE

Copyright (C) 2005 MIZUTANI Tociyuki

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

 Algorithm::Diff3 - compute three way differnces between text.