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Method::Signatures::Modifiers(3pm) User Contributed Perl Documentation Method::Signatures::Modifiers(3pm)

NAME

Method::Signatures::Modifiers - use Method::Signatures from within MooseX::Declare

SYNOPSIS

    use MooseX::Declare;
    use Method::Signatures::Modifiers;
    class Foo
    {
        method bar (Int $thing) {
            # this method is declared with Method::Signatures instead of MooseX::Method::Signatures
        }
    }
    # -- OR --
    use MooseX::Declare;
    class My::Declare extends MooseX::Declare
    {
        use Method::Signatures::Modifiers;
    }
    # ... later ...
    use My::Declare;
    class Fizz
    {
        method baz (Int $thing) {
            # this method also declared with Method::Signatures instead of MooseX::Method::Signatures
        }
    }

DESCRIPTION

Allows you to use Method::Signatures from within MooseX::Declare, both for the "method" keyword and also for any method modifiers ("before", "after", "around", "override", and "augment"). Typically method signatures within MooseX::Declare are provided by MooseX::Method::Signatures. Using Method::Signatures instead provides several advantages:
MooseX::Method::Signatures has a known bug with Perl 5.12.x which does not plague Method::Signatures.
Method::Signatures may provide substantially better performance when calling methods, depending on your circumstances.
Method::Signatures error messages are somewhat easier to read (and can be overridden more easily).
However, Method::Signatures cannot be considered a drop-in replacement for MooseX::Method::Signatures. Specifically, the following features of MooseX::Method::Signatures are not available to you (or work differently) if you substitute Method::Signatures:
Types for Invocants
MooseX::Method::Signatures allows code such as this:
    method foo (ClassName $class: Int $bar) {
    }
Method::Signatures does not allow you to specify a type for the invocant, so your code would change to:
    method foo ($class: Int $bar) {
    }
"where" Constraints
MooseX::Method::Signatures allows code like this:
    # only allow even integers
    method foo (Int $bar where { $_ % 2 == 0 }) {
    }
Method::Signatures does not currently allow this, although it is a planned feature for a future release.
Parameter Aliasing (Labels)
MooseX::Method::Signatures allows code like this:
    # call this as $obj->foo(bar => $baz)
    method foo (Int :bar($baz)) {
    }
This feature is not currently planned for Method::Signatures.
Placeholders
MooseX::Method::Signatures allows code like this:
    method foo (Int $bar, $, Int $baz)) {
        # second parameter not available as a variable here
    }
This feature is not currently planned for Method::Signatures.
Traits
In MooseX::Method::Signatures, "does" is a synonym for "is". Method::Signatures does not honor this.
Method::Signatures supports several traits that MooseX::Method::Signatures does not.
MooseX::Method::Signatures supports the "coerce" trait. Method::Signatures does not currently support this, although it is a planned feature for a future release, potentially using the "does coerce" syntax.

BUGS, CAVEATS and NOTES

Note that although this module causes all calls to MooseX::Method::Signatures from within MooseX::Declare to be completely replaced by calls to Method::Signatures (or calls to Method::Signatures::Modifiers), MooseX::Method::Signatures is still loaded by MooseX::Declare. It's just never used.
The "compile_at_BEGIN" flag to Method::Signatures is ignored by Method::Signatures::Modifiers. This is because parsing at compile-time can cause method modifiers to be added before the methods they are modifying are composed into the Moose classes. Parsing of methods at run-time is compatible with MooseX::Method::Signatures.

THANKS

This code was written by Buddy Burden (barefootcoder).
The import code for replacing MooseX::Method::Signatures is based on a suggestion from Nick Perez.

LICENSE

Copyright 2011 by Michael G Schwern <schwern@pobox.com>.
This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.
See http://www.perl.com/perl/misc/Artistic.html

SEE ALSO

MooseX::Declare, Method::Signatures, MooseX::Method::Signatures.
2012-06-03 perl v5.14.2