Provided by: libvcs-lite-perl_0.12-2_all 
NAME
VCS::Lite - Minimal version control system
SYNOPSIS
use VCS::Lite;
# diff
my $lit = VCS::Lite->new('/home/me/foo1.txt');
my $lit2 = VCS::Lite->new('/home/me/foo2.txt');
my $difftxt = $lit->delta($lit2)->diff;
print OUTFILE $difftxt;
# patch
my $delt = VCS::Lite::Delta->new('/home/me/patch.diff');
my $lit3 = $lit->patch($delt);
print OUTFILE $lit3->text;
# merge
my $lit4 = $lit->merge($lit->delta($lit2),$lit->delta($lit3));
print OUTFILE $lit4->text;
DESCRIPTION
This module provides the functions normally associated with a version control system, but without needing
or implementing a version control system. Applications include wikis, document management systems and
configuration management.
It makes use of the module Algorithm::Diff. It provides the facility for basic diffing, patching and
merging.
API
new
The underlying storage concept of VCS::Lite is an array. The members of the array can be anything that a
scalar can represent (including references to structures and objects). The default is for the object to
hold an array of scalars as strings corresponding to lines of text.
The basic form of the constructor is as follows:
my $lite = VCS::Lite->new( '/my/file');
which slurps the file to make an object. The full form is as follows:
my $lite = VCS::Lite->new( $object_id, $separation, $source, ...);
$object_id
This is a string to identify what is being diffed, patched or merged, in the application's
environment. If there is no $source, this is used as a filename from which to read the content.
$separation
This is an optional parameter, which can be used via $/ to split the input file into tokens. The
default is for lines of text. If you pass in a string to be tokenized, this will use $sep as a
regular expression
$separation can be a scalar or scalar ref, where this is used to break up the input stream. All
values permitted for $/ are allowed (see perlvar).
$separation can also be a hashref, to give a finer level of control. For example:
{ in => '\n',
out => '\n',
chomp => 1 }
'in' is the input record separator to use (the same as you would pass as $sep). Note that all values
allowed for $/, and indeed the value of $/ passed in is what is used as a default. 'in' can be a
string or a regexp.
'out' is the character used on joining the members to output the results (text method in scalar
context). This is the output record separator $\. Note that 'out' defaults differently depening on
the setting of 'chomp': if 'chomp' is off, 'out' will default to the empty string, or rather the
passed in value of $\. If 'chomp' is on, 'out' will default to 'in' - note that you should specify
'out' explicitly if you are using a regexp for 'in'.
If the 'chomp' flag is set, the text matching 'in' is removed from the input lines as they are read.
'chomp' is not on by default, as this is new functionality in release 0.08.
$source
if unspecified causes $object_id to be opened as a file and its entire contents read in. The
alternative is to supply $source, which can be one of the following:
"scalar"
This is a string which is tokenized using $separation
"arrayref"
Array of tokens
"filehandle" or "globref"
Contents of file are slurped
"callback"
This is called successively to obtain tokens until received undef.
In the Perl spirit of DWIM, new assumes that given an arrayref, you have already done all the work of
making your list of whatevers. Given a string (filename) or a file handle, the file is slurped, reading
each line of text into a member of the array. Given a callback, the routine is called successively with
arguments $p1, $p2, etc. and is expected to return a scalar which is added (pushed on) to the array.
apply
$lite->apply($lite2);
$lite->apply($lite3, base => 'original');
This method call corresponds approximately to a version control system's check-in function. This causes
$lite to be modified, so that its contents now reflect those of $lite2.
$lite does retain the original contents, available via original. However, unlike in a version control
system, the object holds only the first original and latest contents.
The VCS::Lite object passed in can also have its own original version. If this is the case, merging will
be performed to incorporate the change as if it had come from a different branch. To facilitiate the
merging process, optionally specify a base version, which can be the string 'original', 'contents' (the
default) or a VCS::Lite object whose contents will be used. This corresponds to the "common ancestor" in
version control systems.
original
This returns a VCS::Lite object for the original version, before changes were applied with apply.
text
my $foo = $lite->text;
my $bar = $lit2->text('|');
my @baz = $lit3->text;
In scalar context, returns the equivalent of the file contents slurped (the optional separation
parameter, defaulting to $_, is used to join the strings together). In list context, returns the list of
lines or records.
id
my $fil = $lite->id
Returns the name associated with the VCS::Lite element when it was created by new. This is usually the
file name.
delta
my $delt = $lit->delta($lit2);
Perform the difference between two VCS::Lite objects. This object returns a VCS::Lite::Delta object.
diff
This is for backward compatibility with early versions. $lite->diff($lite2) is equivalent to
$lite->delta($lite2)->diff.
patch
my $lit3 = $lit->patch($delt);
Applies a patch to a VCS::Lite object. Accepts a file handle or file name string. Reads the file in diff
format, and applies it. Returns a VCS::Lite object for the patched source.
merge
my $lit4 = $lit->merge($lit1,$lit2,\&confl);
Performs the "parallelogram of merging". This applies two different change streams represented by
VCS::Lite objects. Returns a VCS::Lite object with both sets of changes merged.
The third parameter to the method is a sub which is called whenever a merge conflict occurs. This needs
to either resolve the conflict or insert the necessary text to highlight the conflict.
SEE ALSO
Algorithm::Diff.
BUGS, PATCHES & FIXES
At the time of release there is one known bug within VCS-Lite:
http://rt.cpan.org/Public/Bug/Display.html?id=20738
Unfortunately Ivor's original svn repository is no longer available, and any work which had done on
fixing this bug has now been lost. As time allows I will review the examples and try to implement an
appropriate solution.
If you spot a bug or are experiencing difficulties that are not explained within the POD documentation,
please send an email to barbie@cpan.org or submit a bug to the RT system (see link below). However, it
would help greatly if you are able to pinpoint problems or even supply a patch.
http://rt.cpan.org/Public/Dist/Display.html?Name=VCS-Lite
Fixes are dependent upon their severity and my availability. Should a fix not be forthcoming, please feel
free to (politely) remind me.
AUTHOR
Original Author: Ivor Williams (RIP) 2002-2009
Current Maintainer: Barbie <barbie@cpan.org> 2009-2015
COPYRIGHT
Copyright (c) Ivor Williams, 2002-2006
Copyright (c) Barbie, 2009-2015
LICENCE
This distribution is free software; you can redistribute it and/or modify it under the Artistic Licence
v2.
ACKNOWLEDGEMENTS
Colin Robertson for suggesting and providing patches for support of files with unterminated last lines.