source: trunk/essentials/dev-lang/perl/lib/AutoSplit.pm@ 3951

package AutoSplit;

use 5.006_001;
use Exporter ();
use Config qw(%Config);
use Carp qw(carp);
use File::Basename ();
use File::Path qw(mkpath);
use File::Spec::Functions qw(curdir catfile catdir);
use strict;
our($VERSION, @ISA, @EXPORT, @EXPORT_OK, $Verbose, $Keep, $Maxlen,
    $CheckForAutoloader, $CheckModTime);

$VERSION = "1.04";
@ISA = qw(Exporter);
@EXPORT = qw(&autosplit &autosplit_lib_modules);
@EXPORT_OK = qw($Verbose $Keep $Maxlen $CheckForAutoloader $CheckModTime);

=head1 NAME

AutoSplit - split a package for autoloading

=head1 SYNOPSIS

 autosplit($file, $dir, $keep, $check, $modtime);

 autosplit_lib_modules(@modules);

=head1 DESCRIPTION

This function will split up your program into files that the AutoLoader
module can handle. It is used by both the standard perl libraries and by
the MakeMaker utility, to automatically configure libraries for autoloading.

The C<autosplit> interface splits the specified file into a hierarchy 
rooted at the directory C<$dir>. It creates directories as needed to reflect
class hierarchy, and creates the file F<autosplit.ix>. This file acts as
both forward declaration of all package routines, and as timestamp for the
last update of the hierarchy.

The remaining three arguments to C<autosplit> govern other options to
the autosplitter.

=over 2

=item $keep

If the third argument, I<$keep>, is false, then any
pre-existing C<*.al> files in the autoload directory are removed if
they are no longer part of the module (obsoleted functions).
$keep defaults to 0.

=item $check

The
fourth argument, I<$check>, instructs C<autosplit> to check the module
currently being split to ensure that it includes a C<use>
specification for the AutoLoader module, and skips the module if
AutoLoader is not detected.
$check defaults to 1.

=item $modtime

Lastly, the I<$modtime> argument specifies
that C<autosplit> is to check the modification time of the module
against that of the C<autosplit.ix> file, and only split the module if
it is newer.
$modtime defaults to 1.

=back

Typical use of AutoSplit in the perl MakeMaker utility is via the command-line
with:

 perl -e 'use AutoSplit; autosplit($ARGV[0], $ARGV[1], 0, 1, 1)'

Defined as a Make macro, it is invoked with file and directory arguments;
C<autosplit> will split the specified file into the specified directory and
delete obsolete C<.al> files, after checking first that the module does use
the AutoLoader, and ensuring that the module is not already currently split
in its current form (the modtime test).

The C<autosplit_lib_modules> form is used in the building of perl. It takes
as input a list of files (modules) that are assumed to reside in a directory
B<lib> relative to the current directory. Each file is sent to the 
autosplitter one at a time, to be split into the directory B<lib/auto>.

In both usages of the autosplitter, only subroutines defined following the
perl I<__END__> token are split out into separate files. Some
routines may be placed prior to this marker to force their immediate loading
and parsing.

=head2 Multiple packages

As of version 1.01 of the AutoSplit module it is possible to have
multiple packages within a single file. Both of the following cases
are supported:

   package NAME;
   __END__
   sub AAA { ... }
   package NAME::option1;
   sub BBB { ... }
   package NAME::option2;
   sub BBB { ... }

   package NAME;
   __END__
   sub AAA { ... }
   sub NAME::option1::BBB { ... }
   sub NAME::option2::BBB { ... }

=head1 DIAGNOSTICS