From: Trans <transfire@...>
Date: 2008-11-03T04:13:18+09:00
Subject: Re: ruby1.9: lazy versions of Enumerator#select and friends?



On Nov 2, 11:41 am, Brian Candler <b.cand...@pobox.com> wrote:
> I've been having a play with Enumerators in ruby 1.9, in particular
> adding 'lazy' versions of those methods in Enumerable which normally
> return arrays. Here's a proof-of-concept implementation:
>
> module Enumerable
>   def lmap(&blk)
>     Enumerator.new do |y|
>       each do |e|
>         y << blk[e]
>       end
>     end
>   end

This doesn't work. But I think I understand what you are after.

Wouldn't it have to be something like:

   def lmap(&blk)
     this = self
     Functor.new |op, &blk|  # &blk in 1.9 only :(
       this.map(&blk).__send__(op, &blk)
     end
   end

T.