Naive functional composition in Ruby

gistfile1.rb

# Loads a directory's of files, each containing an eponymous function,
# in lexical order, then composes a function the calling of which will
# apply entire chain.

def compose(funcs)
  funcs.map! { |f| f.to_proc }

  if funcs.length == 2
    # simple two function composition
    lambda { |*args| funcs[0].call(funcs[1].call(*args)) }
  elsif funcs.length > 2
    # recursively compose:
    compose(funcs.shift, compose(*funcs))
  else
    lambda { nil }
  end
end

def compose_from_dir(directory)
  steps = Dir.glob("#{directory}/*.rb")
  steps.reverse!.map! do |step|
    load step
    method(step.gsub(/^.*\/\d\d\d_/,"").gsub(".rb","").to_sym)
  end
  if steps.size > 1
    compose(steps)
  else
    steps[0]
  end
end
transform = compose_from_dir("Steps")
puts transform.call("articles")