2 Sub::Prototype::Util - Prototype-related utility routines.
8 use Sub::Prototype::Util qw/flatten recall/;
11 my @args = ( \@a, 1, { d => 2 }, undef, 3 );
13 my @flat = flatten '\@$;$', @args; # ('a', 'b', 'c', 1, { d => 2 })
14 recall 'CORE::push', @args; # @a contains 'a', 'b', 'c', 1, { d => 2 }, undef, 3
17 Prototypes are evil, but sometimes you just have to bear with them,
18 especially when messing with core functions. This module provides
19 several utilities aimed at facilitating "overloading" of prototyped
22 They all handle 5.10's "_" prototype.
25 "flatten $proto, @args"
26 Flattens the array @args according to the prototype $proto. When @args
27 is what @_ is after calling a subroutine with prototype $proto,
28 "flatten" returns the list of what @_ would have been if there were no
32 Calls the function $name with the prototyped argument list @args. That
33 is, @args should be what @_ is when you define a subroutine with the
34 same prototype as $name. For example,
37 recall 'CORE::push', $a, 1, 2, 3;
39 will call "push @$a, 1, 2, 3" and so fill the arrayref $a with "1, 2,
40 3". This is especially needed for core functions because you can't
43 You can also force the use of a specific prototype. In this case, $name
44 must be a hash reference that holds exactly one key/value pair, the key
45 being the function name and the value the prototpye that should be used
48 recall { 'CORE::push' => '\@$' }, $a, 1, 2, 3; # will only push 1
50 This allows you to recall into "CORE::grep" and "CORE::map" by using the
53 sub mygrep (&@) { recall { 'CORE::grep' => '\&@' }, @_ } # the prototypes are intentionally different
56 The functions "flatten" and "recall" are only exported on request,
57 either by providing their name or by the ':funcs' and ':all' tags.
60 Carp, Exporter (core modules since perl 5), Scalar::Util (since 5.7.3).
63 Vincent Pit, "<perl at profvince.com>", <http://www.profvince.com>.
65 You can contact me by mail or on #perl @ FreeNode (vincent or
69 Please report any bugs or feature requests to "bug-sub-prototype-util at
70 rt.cpan.org", or through the web interface at
71 <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Sub-Prototype-Util>. I
72 will be notified, and then you'll automatically be notified of progress
73 on your bug as I make changes.
76 You can find documentation for this module with the perldoc command.
78 perldoc Sub::Prototype::Util
80 Tests code coverage report is available at
81 <http://www.profvince.com/perl/cover/Sub-Prototype-Util>.
84 Copyright 2008 Vincent Pit, all rights reserved.
86 This program is free software; you can redistribute it and/or modify it
87 under the same terms as Perl itself.