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Re: reduce metaoperator on an empty list

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From:
=?ISO-8859-1?Q?=22TSa_=28Thomas_Sandla=DF=29=22?=
Date:
June 8, 2005 02:41
Subject:
Re: reduce metaoperator on an empty list
Message ID:
42A6BD21.5000006@orthogon.com
Damian Conway wrote:
> So, to clarify again, if $var is undefined, then the assignment:
> 
>     $var op= $value;
> 
> is equivalent to:
> 
>     $var = (&op.does(identval) ?? &op.identval() :: undef) op $value;
> 
> Correct?

Might I add that it should read

       $var = (&op.does(identval) ??
               &op.identval($value) :: undef) op $value;

The rational is, that &op is subject to MMD, so the .identval method
should be dispatched as well. Actually &op.identity($value) reads
quite natural and self documenting if the parameter is required.

Hmm, the MMD form identity( &op, $value ) looks even better. This
folds the identity value selection problem back into type-space
and it's runtime agent MMD.
-- 
TSa (Thomas SandlaƟ)


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