From: Bruno Michel <bruno@...>
Date: 2006-09-29T19:23:13+09:00
Subject: Re: Regexp help

Vincent Fourmond a �crit :
>   Hello again !
> 
>>> I have a string of the form
>>>
>>> 2h 3m
>>>
>>> or
>>>
>>> 3m 2h
>>> [....]
>>> Is there a smart regexp one liner that could produce
>>>
>>> [2, 3]
>>   If you want to get [2,3] in both cases, that will be really difficult.
>> As far as I know, you can only do that in C#, which has named capturing
>> groups. In all the other languages I know, the capturing groups are
>> numbered when they are found... That rules it out.
> 
>   Well, just to contradict myself, although this is no one-liner:
> 
> def scan(str)
>   re = Regexp.new(/(\d+)h.*(\d+)m|(\d+)m.*(\d+)h/)
>   if m = re.match(str)
>     return [m[1], m[2]] if m[1]
>     return [m[4], m[3]]
>   end
> end
> 
> p scan("2h 3m")
> p scan("3m 2h")
> 
>   Cheers !
> 
> 	Vince
> 

And the one-liner :

$ irb
 >> "3m 
2h".scan(/(\d+)h.*(\d+)m|(\d+)m.*(\d+)h/).flatten.values_at(0,1,3,2).compact
=> ["2", "3"]
 >> "2h 
3m".scan(/(\d+)h.*(\d+)m|(\d+)m.*(\d+)h/).flatten.values_at(0,1,3,2).compact
=> ["2", "3"]


It's possible to add .map { |i| i.to_i } at the end of this one-liner if 
the result array must contain integers instead of strings.

-- 
Bruno Michel