[ruby-core:69712] [Ruby trunk - Feature #6284] Add composition for procs

Issue #6284 has been updated by Paul Mucur.

File 0003-proc.c-Support-any-callable-when-composing-Procs.patch added

Attached patch to support composing with any object that responds to `call` (rather than raising a `TypeError` if the object was not a `Proc` or `Method`), e.g.

~~~
class Foo
  def call(x, y)
    x + y
  end
end

f = proc { |x| x * 2 }
g = f * Foo.new

g.call(1, 2) #=> 6
~~~

----------------------------------------
Feature #6284: Add composition for procs
https://bugs.ruby-lang.org/issues/6284#change-53092

* 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)


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