From: Michal Suchanek <hramrach@...>
Date: 2010-02-07T04:47:46+09:00
Subject: Re: match/scan does not return multiple matches

On 6 February 2010 19:57, Ralf Mueller <ralf.mueller@zmaw.de> wrote:
> Michal Suchanek wrote:
>>
>> Hello
>>
>> I tried scanning for multiple occurences of a group in a string and
>> match/scan would return only one.
>>
>>
>> "ajabcabck".match /^a*j(?:b*(a+)b+c*)+k$/
>> => #<MatchData "ajabcabck" 1:"a">
>>
>> "ajabcabck".scan /^a*j(?:b*(a+)b+c*)+k$/
>> => [["a"]]
>>
>>
>> clearly the a+ group must match twice to match the string from ^ to $
>> but only single match is returned.
>>
>> It is possible to use split instead but using a single match would be
>> much nicer.
>>
>> Any workaround?
>>
>> ruby 1.8.7 (2010-01-10 patchlevel 249) [i486-linux]
>>
>>
>> Thanks
>>
>> Michal
>>
>>
>
> Hi
> as far as i know, nested groups are not allowed. regular expressions do not
> form a language.

Actually they are allowed, otherwise I would not get a match at all.
Note also that I have manually unnested them in the example. The
problem is that repeated matches of the group are not returned.

Thanks

Michal