From: Minero Aoki <aamine@...>
Date: 2003-02-04T02:50:32+09:00
Subject: ruby-dev summary 19437-19455

Hi all,

This is a summary of ruby-dev ML in these days.


[ruby-dev:19441] Integer#gcd

  Masaki requested a new method Integer#gcd.
  Shugo Maeda suggested alternative name, Math.gcd(m,n).

[ruby-dev:19449] new keyword once

  See following simple search programs:

    #1
    ARGF.each do |line|
      print line if line.index('PATTERN')
    end

    #2
    ARGF.each do |line|
      print line if line.index(/PATTERN/)
    end

  In most cases, Program #1 is SLOWER than #2.  The reason is that
  a string literal creates a new object for each iteration.  So the
  following program is faster than #1.

    #3
    pattern = 'PATTERN'
    ARGF.each do |line|
      print line if line.index(pattern)
    end

  K.Kosako proposed a new keyword `once' to resolve such kind of
  problems.  For example, following program creates a string object
  only once (as of program #3).

    ARGF.each do |line|
      print line if line.index(once 'PATTERN')
    end

  Matz considers that the better plan is to make string literal create
  an object only once.


-- Minero Aoki