Issue #6284 has been updated by Paul Mucur.


Pablo Herrero wrote:
> I don't believe you need a pure PF language to benefit from a feature like this. Many ETL projects like transproc (https://github.com/solnic/transproc) would probably find it useful too.

Transproc is what actually inspired me to submit a patch here: my hope is that having functional composition in the Ruby language itself will enable easier data pipelining using only `Proc`s, `Method`s and other objects implementing `call`. The presence of `curry` (http://ruby-doc.org/core-2.2.2/Proc.html#method-i-curry) seems like a good precedent for adding such functional primitives to the core.


----------------------------------------
Feature #6284: Add composition for procs
https://bugs.ruby-lang.org/issues/6284#change-53215

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


-- 
https://bugs.ruby-lang.org/