NAME Sub::Prototype::Util - Prototype-related utility routines. VERSION Version 0.07 SYNOPSIS use Sub::Prototype::Util qw/flatten recall wrap/; my @a = qw/a b c/; my @args = ( \@a, 1, { d => 2 }, undef, 3 ); my @flat = flatten '\@$;$', @args; # ('a', 'b', 'c', 1, { d => 2 }) recall 'CORE::push', @args; # @a contains 'a', 'b', 'c', 1, { d => 2 }, undef, 3 my $splice = wrap 'CORE::splice', compile => 1; my @b = $splice->(\@a, 4, 2); # @a is now ('a', 'b', 'c', 1, 3) and @b is ({ d => 2 }, undef) DESCRIPTION Prototypes are evil, but sometimes you just have to bear with them, especially when messing with core functions. This module provides several utilities aimed at facilitating "overloading" of prototyped functions. They all handle 5.10's "_" prototype. FUNCTIONS "flatten $proto, @args" Flattens the array @args according to the prototype $proto. When @args is what @_ is after calling a subroutine with prototype $proto, "flatten" returns the list of what @_ would have been if there were no prototype. "recall $name, @args" Calls the function $name with the prototyped argument list @args. That is, @args should be what @_ is when you define a subroutine with the same prototype as $name. For example, my $a = [ ]; recall 'CORE::push', $a, 1, 2, 3; will call "push @$a, 1, 2, 3" and so fill the arrayref $a with "1, 2, 3". This is especially needed for core functions because you can't "goto" into them. You can also force the use of a specific prototype. In this case, $name must be a hash reference that holds exactly one key/value pair, the key being the function name and the value the prototpye that should be used to call it. recall { 'CORE::push' => '\@$' }, $a, 1, 2, 3; # will only push 1 This allows you to recall into "CORE::grep" and "CORE::map" by using the "\&@" prototype : sub mygrep (&@) { recall { 'CORE::grep' => '\&@' }, @_ } # the prototypes are intentionally different "wrap $name, %opts" Generates a wrapper that does the same thing as "recall", but specialized for a given function. This wrapper can be compiled once for all to avoid calling "eval" at each run (like "recall" does). You can still force the prototype by passing "{ $name => $proto }" as the first argument. Others arguments are seen as key / value pairs and tune the code generated by "wrap". Valid keys are : "ref => $func" Specifies the function used in the generated code to test the reference type of scalars. Defaults to 'ref'. You may also want to use "Scalar::Util::reftype". "wrong_ref => $code" The code executed when a reference of incorrect type is encountered. The result of this snippet is also the result of the generated code, hence it defaults to 'undef'. It's a good place to "croak" or "die" too. "sub => $bool" Encloses the code into a "sub { }" block. Default is true. "compile => $bool" Makes "wrap" compile the code generated and return the resulting code reference. Implies "sub => 1". Be careful that in this case "ref" must be a fully qualified function name. Defaults to false. This is how you make your own "push" that pushes into array references : my @a = (0 .. 2); my $push = wrap 'CORE::push', compile => 1; $push->(\@a, 3 .. 7); # returns 3 + 5 = 8, and @a now contains 0 .. 7 EXPORT The functions "flatten", "recall" and "wrap" are only exported on request, either by providing their name or by the ':funcs' and ':all' tags. DEPENDENCIES Carp, Exporter (core modules since perl 5), Scalar::Util (since 5.7.3). AUTHOR Vincent Pit, "", . You can contact me by mail or on #perl @ FreeNode (vincent or Prof_Vince). BUGS Please report any bugs or feature requests to "bug-sub-prototype-util at rt.cpan.org", or through the web interface at . I will be notified, and then you'll automatically be notified of progress on your bug as I make changes. SUPPORT You can find documentation for this module with the perldoc command. perldoc Sub::Prototype::Util Tests code coverage report is available at . COPYRIGHT & LICENSE Copyright 2008 Vincent Pit, all rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.