Regular Expressions

ruby-talk
1

hi,

is there any way to reuse a group in a regular expression in ruby?

In other languages you can reuse a group by write (?<name> ....).

But I can't figure out how to do this in ruby?

Do you have some advice?

Thanks
   Peter

2

hi,

is there any way to reuse a group in a regular expression in ruby?

In other languages you can reuse a group by write (?<name> ....).

But I can't figure out how to do this in ruby?

Do you have some advice?

Ruby's current regexp engine does not support named groups. You can however reference by count:

>> /(b+)a+\1/ =~ ("aaabbb"*10)
=> 3
>> ("aaabbb"*10).scan /(b+)a+\1/
=> [["bbb"], ["bbb"], ["bbb"], ["bbb"], ["bbb"]]
>> ("aaabbb"*10).scan /((b+)a+\2)/
=> [["bbbaaabbb", "bbb"], ["bbbaaabbb", "bbb"], ["bbbaaabbb", "bbb"], ["bbbaaabbb", "bbb"], ["bbbaaabbb", "bbb"]]
>>

HTH

  robert

···

On 30.08.2006 12:29, Peter Meier wrote:

3

Robert Klemme wrote:

Ruby's current regexp engine does not support named groups.

For the sake of providing complete information, Ruby's next regexp engine (oniguruma) will. You can play around with it in the 1.9 branch (at least it was used there last time I checked.) I don't know if you can use it standalone.

David Vallner