From: Mike Steiner <mikejaysteiner@...>
Date: 2007-05-27T08:57:31+09:00
Subject: are MatchData objects mutable?

------=_Part_98645_21719045.1180223851654
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

A few times in my programs I've tried to modify elements of the array
returned by .match, and it always causes strange errors later in my code.

For example, if I do:

s = "aaa bbb ccc"
m = /(.*) (.*) (.*)/.match(s)
m[1].sub! ( "aa" , "" )

I get strange results, but if I instead do:

s = "aaa bbb ccc"
m = /(.*) (.*) (.*)/.match(s)
x = m[1].dup
x.sub! ( "aa" , "" )

it works fine. What's going on?

Mike Steiner

------=_Part_98645_21719045.1180223851654--