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Re: Roles and Mix-ins?
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From:
Piers Cawley
Date:
January 7, 2004 00:11
Subject:
Re: Roles and Mix-ins?
Message ID:
m2fzes6uw2.fsf@obelisk.bofh.org.uk
Jonathan Lang <dataweaver42@yahoo.com> writes:
> Luke Palmer wrote:
>> Renaming methods defeats the purpose of roles. Roles are like
>> interfaces inside-out. They guarantee a set of methods -- an interface
>> -- except they provide the implementation to (in terms of other,
>> required methods). Renaming the method destroys the interface
>> compatibility.
>
> Not so. A role is more than an inside-out interface; it guarantees a set
> of methods either by calling it an error to not define a given method in a
> class that C<does> the role or by defining the method itself. In the
> latter case, renaming the method can be quite useful; even in the former
> case, renaming or excluding methods from a role is useful if you want an
> interface which is almost, but not quite, like the one that the role
> provides.
And examples of doing all of that are given in the original Traits
paper (and, for that matter, in the summary of Traits/Roles that I
wrote up for the summary.)
--
Beware the Perl 6 early morning joggers -- Allison Randal
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