From: Heesob Park <phasis@...>
Date: 2009-04-29T22:29:04+09:00
Subject: Re: Issue with regexp pattern matcher withing String#gsub

2009/4/29 Brian Candler <b.candler@pobox.com>:
> Heesob Park wrote:
>> 2009/4/29 Craig Jolicoeur <cpjolicoeur@gmail.com>:
>>> ## to
>>> ##  from (irb):84
>>>
>>> html_string.gsub!( /src=(["'])\S+\?\d*\1/ ) { |s| s.split('?').first +
>>> $1 }
>>>
>>> ## the question is why can I do string concat with + $1 in the first
>>> regexp and
>>> ## why am I unable to do it in the second regexp where doing str + $1
>>> throws the error??
>> The side effect of String#split is changing the value of $1.
>
> It doesn't in ruby 1.8.6:
>
> irb(main):007:0> /(.)/ =~ "abc"; puts $1; "a b".split(" "); puts $1
> a
> a
> => nil
>
> It will if the split is done on a Regexp (but the OP wasn't doing that)
>
> irb(main):008:0> /(.)/ =~ "abc"; puts $1; "a b".split(/ /); puts $1
> a
> nil
> => nil
It does in ruby 1.8.6
irb(main):007:0> /(.)/ =~ "abc"; puts $1; "a?b".split("?"); puts $1
a
nil
=> nil

Regards,

Park Heesob