Haskell-like function composition in Ruby - let the mad horses unleash

wtf.rb

require 'blankslate'

class Proc
  def self.comp(f, g)
    lambda { |*args| f[g[*args]] }
  end

  def *(g)
    Proc.comp(self, g)
  end
end

module Kleisli
  class ComposedFn < BlankSlate
    def initialize(fns=[])
      @fns = fns
    end

    def method_missing(m, *args, &block)
      fn = -> a, x { x.send(m, *a) }.curry[args]
      ComposedFn.new(@fns + [fn])
    end

    def call(*args)
      @fns.reduce(:*).call(*args)
    end
  end
end

_ = Kleisli::ComposedFn.new

# BE MAD
fn = _ . first . last
puts fn.call([[1,2],[3,4]]) # => 3