From: MenTaLguY <mental@...>
Date: 2005-11-06T02:14:23+09:00
Subject: Re: [ANN] lazy.rb

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On Sat, 2005-11-05 at 11:46 +0900, Pit Capitain wrote:
> MenTaLguY schrieb:
> > ...
> > Same problem in both cases, basically.
>=20
> Here's another implementation that doesn't have these problems:
>=20
>    module Lazy #:nodoc: all
>      class Thunk
>        instance_methods.each { |m| undef_method m unless m =3D~ /^__/ }
>        def initialize( &computation )
>          @computation =3D computation
>        end
>        def method_missing( *args, &block )
>          ( @result ||=3D @computation.call( self ) ).send( *args, &block =
)
>        end
>      end
>    end

Hmm, I can adapt this, I think.  Thanks.  It does have a few problems as
written; e.g.:

 1. since @computation isn't set to nil after being run, the closure
    can't get garbage collected until the thunk is

 2. the computation will get run multiple times if its result is nil
    or false

 3. There's no way to unwrap the value from the thunk

But I think you got me over the hump.  Look for another lazy.rb release
soonish.

-mental

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