From: Sean O'Halpin <sean.ohalpin@...>
Date: 2005-09-16T10:20:39+09:00
Subject: Re: Math: sum and faculty

> sum = enum.accumulate(0, :+) {|x| f(x)}

How about

module Enumerable

  def accumulate(initial, method, &block)
    if not block_given?
      block = proc {|x| x}
    end
    inject(initial) {|accumulator, value|
      #
      # apply block to input value
      #
      accumulator.send(method, block.call(value))
      }
  end

end

It's worth getting to know inject however.

Sean