From: Martin DeMello <martindemello@...>
Date: 2003-08-31T05:23:31+09:00
Subject: Re: multiply all array with array

Sabby and Tabby <sabbyxtabby@yahoo.com> wrote:
> 
> Should #mapwith work with 3 or more arrays like #zip does?
> 
>  p [1,2,3].mapwith([4,5,6], [7,8,9]) {|i,j,k| i*j+k}

Right you are. I'll rework it in the a.m. - too sleepy right now :) 

> Allowing #zip to take a block has been discussed before.  Here's yet
> another implementation:
> 
>  class Array
>    alias _zip zip
>    def zip(*args)
>      if block_given?
>        _zip(*args).map {|a| yield a}
>      else
>        _zip(*args)
>      end
>    end
>  end
> 
>  p [1,2,3].zip([4,5,6], [7,8,9]) {|i,j,k| i*j+k}
> 
> Unfortunately, it doesn't allow taking a symbol to an operator (:*)
> like #mapwith does.

The symbol was my main motivation for writing it, actually - map {|x,y|
x*y} just felt redundant.

martin