From: Vincent Foley <vinfoley@...>
Date: 2002-09-24T02:18:07+09:00
Subject: Problems with String#gsub!

I have here a program to help me do crossword puzzles.  Yesturday, I
added the (c) and (v) symbols to match consonants and vowels
respectivly.  The problem is that they do not seem to work the way I
intend them to.  Here's the program:

[code]
#!/usr/bin/env ruby

wordList = open('/home/vince/fr_dict.txt', 'r').read.split('\n')
repl = {
    '_'   => '[a-�]',
    '(v)' => '[a���e���i��o��u���y]', 
    '(c)' => '[bcdfghjklmnpqrstvwxyz]',
    '(e)' => '[�e���]'
}    

while true
  print '> '
  reg = gets.chomp
  repl.each_key { |token|
    reg.gsub!(token, repl[token])
  }
  reg = '^' << reg << '$'
  puts reg
  for word in wordList
    puts word if word =~ reg
  end
end
[/code]

And here's a sample session where it does not do what I expect it to
(and gives wrong results):

[quote]
[vince@vincent: ~/prog/ruby]% ./crosswords.rb
> (c)(v)(v)
^([bcdfghjklmnpqrst[a���e���i��o��u���y]wxyz])([a���e���i��o��u���y])([a���e���i��o��u���y])$
>
[/code]

I would've expected my regular expression to be:
^[bcdfghjklmnpqrstvwxyz][a���e���i��o��u���y][a���e���i��o��u���y]$

Why did it keep the parenthesis? Why did it replace the v with the
complet vowel set?

Thanks for you help,

Vince

-- 

Vincent Foley-Bourgon
Email: vinfoley@iquebec.com
Homepage: http://darkhost.mine.nu:81