From: "pabloh (Pablo Herrero)" <pablodherrero@...>
Date: 2012-04-16T11:59:25+09:00
Subject: [ruby-core:44373] [ruby-trunk - Feature #6284] Add composition for procs


Issue #6284 has been updated by pabloh (Pablo Herrero).


alexeymuranov (Alexey Muranov) wrote:
> 
> Update: i think having the both was a bad idea, it would be redundant.

I was going to say the same thing. Having both #* and #| is redundant and also a bit confusing, since #| doesn't really feel to be the opposite operation of #* at any context. We should choose one or the other but not both. 
I still like #| (with association from left to right) a bit better, but I rather have #* than nothing.
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Feature #6284: Add composition for procs
https://bugs.ruby-lang.org/issues/6284#change-25917

Author: pabloh (Pablo Herrero)
Status: Assigned
Priority: Normal
Assignee: matz (Yukihiro Matsumoto)
Category: 
Target version: 2.0.0


=begin
It would be nice to be able to compose procs like functions in functional programming languages:

    to_camel = :capitalize.to_proc
    add_header = ->val {"Title: " + val}

    format_as_title = add_header << to_camel << :strip

instead of:

    format_as_title = lambda {|val| "Title: " + val.strip.capitalize }


It's pretty easy to implement in pure ruby:

  class Proc
    def << block
      proc { |*args| self.call( block.to_proc.call(*args) ) }
    end
  end
=end


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