package PatchReader;

use strict;

=head1 NAME

PatchReader - Utilities to read and manipulate patches and CVS

=head1 SYNOPSIS

  # script that reads in a patch (in any known format), and prints out some
  # information about it.  Other common operations are outputting the patch
  # in a raw unified diff format, outputting the patch information to
  # Template::Toolkit templates, adding context to a patch from CVS, and
  # narrowing the patch down to apply only to a single file or set of files.

  use PatchReader::Raw;
  use PatchReader::PatchInfoGrabber;
  my $filename = 'filename.patch';

  # Create the reader that parses the patch and the object that extracts info
  # from the reader's datastream
  my $reader = new PatchReader::Raw();
  my $patch_info_grabber = new PatchReader::PatchInfoGrabber();
  $reader->sends_data_to($patch_info_grabber);

  # Iterate over the file
  $reader->iterate_file($filename);

  # Print the output
  my $patch_info = $patch_info_grabber->patch_info();
  print "Summary of Changed Files:\n";
  while (my ($file, $info) = each %{$patch_info->{files}}) {
    print "$file: +$info->{plus_lines} -$info->{minus_lines}\n";
  }

=head1 ABSTRACT

This perl library allows you to manipulate patches programmatically by
chaining together a variety of objects that read, manipulate, and output
patch information:

PatchReader::Raw
- parse a patch in any format known to this author (unified, normal, cvs diff,
  among others)
PatchReader::PatchInfoGrabber
- grab summary info for sections of a patch in a nice hash
  of a patch, for example)
PatchReader::AddCVSContext
- add context to the patch by grabbing the original files from CVS
PatchReader::NarrowPatch
- narrow a patch down to only apply to a specific set of files

PatchReader::DiffPrinter::raw
- output the parsed patch in raw unified diff format
PatchReader::DiffPrinter::template
- output the parsed patch to Template::Toolkit templates (can be used to make
  HTML output or anything else you please)

Additionally, it is designed so that you can plug in your own objects that
read the parsed data while it is being parsed (no need for the performance or
memory problems that can come from reading in the entire patch all at once).
You can do this by mimicking one of the existing readers (such as
PatchInfoGrabber) and overriding the methods start_patch, start_file, section,
end_file and end_patch.

=cut

$PatchReader::VERSION = '0.9.5';

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