From: ts <decoux@...>
Date: 2003-04-08T01:06:20+09:00
Subject: Re: a question about regexp

>>>>> "B" == Ben Thomas <ben.thomas@wickedstudios.com> writes:

B> Displaying $& in the inner loop of grep works fine, but when it enter my own
B> block, $& is put back to nil. Is there a way to keep the value of $& (and
B> all others $1...)?

 Well, $~ is a local, and thread local variable and perhaps in your case it
 best to give this variable to the block, something like

   def mygrep( exp )
      ar = [ "element1", "element2" ]
      ar.grep( exp ) { |e|
         yield e, $~
      }
   end

   mygrep( /(.*)/ ) { |e, match|
      # doesn't work...
      print "mygrep: #{match[0]}\n"
   }

 $~ is an object MatchData

pigeon% ri MatchData
------------------------------------------------------------------------
     class: MatchData
------------------------------------------------------------------------
     MatchData is the type of the special variable $~, and is the type
     of the object returned by Regexp#match and Regexp#last_match. It
     encapsulates all the results of a pattern match, results normally
     accessed through the special variables $&, $', $`, $1, $2, and so
     on.

------------------------------------------------------------------------
     [], begin, end, length, offset, post_match, pre_match, size,
     string, to_a, to_s
------------------------------------------------------------------------
pigeon% 




Guy Decoux