From: Jim Freeze <jim@...>
Date: 2002-03-20T06:25:56+09:00
Subject: Re: Why is Ruby so slow? - Solution

On Wed, Mar 20, 2002 at 05:26:27AM +0900, Venherm Borchers wrote:
> Dear colleagues,
> 
> The solution
> ------------
> 
> Nobu Nakada pointed out that the following line might be causing the
> problem, and it indeed does:
> 
>         nitms = (@col[j]-['']).nitems
> 
> Here I relied on the 'set difference' that returns an array of only
> unique elements which then are counted. I have to warn you: this kind
> of set operation is _unbelievably_ slow!
> 
How did you implement @col[j]-[''] to get a speed improvement?


-- 
Jim Freeze
atto:       1e-18 = one quintillionth
parsec:     3.258 light-years: 3.258 * 186000 * 364 * 24 * 3600 * 5280 * 12
attoparsec: atto * parsec =~ 1.20 inch
My height:  62 inches / 1.2 = 51.7 attoparsecs
~