From: Robert Klemme <bob.news@...>
Date: 2004-09-05T04:55:16+09:00
Subject: Re: OK... :) question about hash and array literals


"Patrick May" <patrick@hexane.org> schrieb im Newsbeitrag 
news:4916C543-FEA8-11D8-81CB-000A95848050@hexane.org...
> Hello,
>
> My main use for using ordered hashes is to express repeated regexp string 
> transformations.  For example, in php I use this series of regexp's to 
> clean up html spacing:
>
>   foreach(  array(  '/\n|\f|\r/' => " ",
>                               '/\s+/' => " ",
>                               '/\s*<\/p>/i' => "</p>",
>                               '/<p><(&nbsp;)?\/p>/i' => "",
>                               '/<p>/i' => "\n\n<p>",
>                               '/<p>$/i' => "", ) as $p => $r ) {
>     $string = preg_replace( $p, $r, $string );
>   }
>
> There are of course other uses, but has been a real handy one for me.

In this case nested arrays are sufficient since you don't need efficient 
lookup.  The only access is iteration as far as I can see.  Example:

transformations = [
  [/foo/, "bar"],
  [/baz/, "xxx"],
  [/\s+/, " "],
]

text = "xxx foo ddddd bar bazsiud"

transformations.each {|rx, repl| text.gsub!(rx, repl) }

Kind regards

    robert