From: Jesse Merriman <jesse.d.merriman@...>
Date: 2007-03-26T08:08:20+09:00
Subject: Re: Backus, Functional Programming, and Ruby

On Sunday 25 March 2007 18:47, Devin Mullins wrote:
> module Enumerable
>    def inner_product
>      transpose.map(&:*).inject(&:+)
>    end
> end

That looks good, but is it right?

irb(main):001:0> module Enumerable
irb(main):002:1>   def inner_product
irb(main):003:2>     transpose.map(&:*).inject(&:+)
irb(main):004:2>   end
irb(main):005:1> end
=> nil
irb(main):006:0> [[0,1,2], [6,5,4]].inner_product
TypeError: wrong argument type Symbol (expected Proc)
        from (irb):3:in `inner_product'
        from (irb):6

$ ruby --version
ruby 1.8.5 (2006-12-04 patchlevel 2) [i686-linux]

-- 
Jesse Merriman
jessemerriman@warpmail.net
http://www.jessemerriman.com/