From: GOTO Kentaro <gotoken@...>
Date: 2002-08-08T01:26:29+09:00
Subject: Re: sort problem

At Wed, 7 Aug 2002 14:31:47 +0900,
WATANABE Hirofumi wrote:
> :foo = foo.sort {|a,b| c,d = r.match(a)[1,2]
> :                      e,f = r.match(b)[1,2]
> :                      c <=> e or d.to_i <=> f.to_i}
> :puts foo
> 
> How about Array#<=> ?
> 
>   [c, d.to_i] <=> [e, f.to_i]

And Ruby 1.7 has Array#sort_by.

  foo = foo.sort_by { |i| 
    e,f = r.match(a)[1,2]
    [e, f.to_i]
  }

By the way, this example reminds me.  
I would sometimes like to modifiy an array in a method chain. 
So, I wrote Array#sub_at and Array#sub.  With this method, above can be 
rewritten as follows:

  foo = foo.sort_by { |i| r.match(a)[1,2].sub_at(1) { |f| f.to_i } }

Or the original problem [ruby-talk:46468] can be answered as:

  % cat ruby-talk:46468.rb
  require "arraysub"
  puts ARGF.readlines.sort_by { |line|
    line.scan(/\D+|\d+/).sub(/\d/) { |f| f.to_i }
  }

  % cat ruby-talk:46468.dat
  ina1
  ina15
  inb12
  ina9
  inc10
  inda12
  inef14
  inab14
  inzz8
  inzz80
  inzz9

  % ruby17 ruby-talk:46468.rb ruby-talk:46468.dat
  ina1
  ina9
  ina15
  inab14
  inb12
  inc10
  inda12
  inef14
  inzz8
  inzz9
  inzz80

I've put arraysub.rb at 
http://www.notwork.org/~gotoken/ruby/p/as-is/arraysub.rb

-- Gotoken