NAME

Array::Functions::Undoable - Array manipulation functions which supports undo operation

VERSION

version 0.01

SYNOPSIS

use Array::Functions::Undoable qw(afu);

# raw "low-level" functional interface
my $ary = [0, 1, 2, 3];
my $res1 = afu(op=>'pop'    , ary=>$ary);          # ary now [0, 1, 2]
my $res2 = afu(op=>'pluck'  , ary=>$ary);          # ary now [0, 2]
my $res3 = afu(op=>'unshift', ary=>$ary, item=>4); # ary now [4, 0, 2]

# undo
afu(op=>'unshift', ary=>$ary, -undo_action=>'undo',
    -undo_data=>$res3->[3]{undo_data});      # ary now [0, 2]
afu(op=>'pluck'  , ary=>$ary, -undo_action=>'undo',
    -undo_data=>$res2->[3]{undo_data});      # ary now [0, 1, 2]
afu(op=>'pop'    , ary=>$ary, -undo_action=>'undo',
    -undo_data=>$res1->[3]{undo_data});      # ary now [0, 1, 2, 3]

# nicer OO interface, which provides an undo stack. not yet implemented.

my $afu = Array::Functions::Undoable->new;
$ary = [0, 1, 2, 3]

$afu->pop($ary);        # ary now [0, 1, 2]
$afu->pluck($ary);      # ary now [0, 2]
$afu->unshift($ary, 4); # ary now [4, 0, 2]

$afu->undo;             # ary now [0, 2]
$afu->redo;             # ary now [4, 0, 2]

$afu->undo;             # ary now [0, 2]
$afu->undo;             # ary now [0, 1, 2]
$afu->undo;             # ary now [0, 1, 2, 3]

$afu->undo;             # does nothing, undo stack empty

DESCRIPTION

This module provides the usual array manipulation functionalities like for popping, pushing, splicing, but with undo capability. It is currently used just for testing the Sub::Spec undo protocol and other Sub::Spec modules like Sub::Spec::Runner.

FUNCTIONS

None of the functions are exported by default, but they are exportable.

afu(%args) -> [STATUS_CODE, ERR_MSG, RESULT]

Perform undoable array operations.

Returns a 3-element arrayref. STATUS_CODE is 200 on success, or an error code between 3xx-5xx (just like in HTTP). ERR_MSG is a string containing error message, RESULT is the actual result.

This function supports undo operation. See Sub::Spec::Clause::features for details on how to perform do/undo/redo.

Arguments (* denotes required arguments):

• ary* => array

  The array.

• item =>

  Item to insert to array.

  Required when doing these operations: unshift, push.

• op* => str

  Value must be one of:

  ["pop", "push", "shift", "unshift", "pluck"]

  Operation on array.

SEE ALSO

Sub::Spec

AUTHOR

Steven Haryanto <stevenharyanto@gmail.com>

COPYRIGHT AND LICENSE

This software is copyright (c) 2011 by Steven Haryanto.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.