[ruby-core:69777] [Ruby trunk - Feature #6284] Add composition for procs

[pablodherrero@gmail.com]

Issue #6284 has been updated by Pablo Herrero.


It would be nice to be able to compose functions in both ways, like in F#, you can do `g << f` or `g >> f`, sadly this was rejected before.

I would settle to have `Proc#*` for "regular" composition and `Proc#|` for "piping".
Last time there was no consensus about the syntax. Hopefully we can manage to solve this before 2.3 is released.

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Feature #6284: Add composition for procs
https://bugs.ruby-lang.org/issues/6284#change-53156

* Author: Pablo Herrero
* Status: Feedback
* Priority: Normal
* Assignee: Yukihiro Matsumoto
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=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

---Files--------------------------------
0002-proc.c-Implement-Method-for-Method-composition.patch (2.71 KB)
0001-proc.c-Implement-Proc-for-Proc-composition.patch (3.73 KB)
0003-proc.c-Support-any-callable-when-composing-Procs.patch (4.01 KB)


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