Re: named captures assigning to local variables

Attached is a variation on my patch that makes it return $~ instead of 
an array of values.  In testing this I remembered that $~[0] is the 
entire string on the right-hand side, rather than the first captured 
value, so this return value doesn't actually masquerade as an array of 
the assigned values.  So I'm a little less enthusiastic about this 
return value.

(Shouldn't MatchData be Enumerable, by the way?)

	David

David Flanagan wrote:
> Tanaka Akira wrote:
>> In article 
>> <S2445477AbXLTQsI/[e-mail]>,
>>   David Flanagan <[e-mail]> writes:
>>
>>> How about making the return value an array of the captured strings, 
>>> or nil if there was no match? 
>>
>> Another idea is $~, which is a MatchData or nil.
> 
> That's simpler to implement than what I had done.  And in the simple 
> case when all capturing groups have names, $~ behaves like an array of 
> the captured values, doesn't it?  I think I like this.
> 
> Another option is to raise an exception if the match fails.  I can 
> almost convince myself that this is the right thing to do for this kind 
> of assignment...  But Ruby is usually more forgiving, so probably not.
> 
> Another option is to return an empty array when the pattern fails to 
> match, indicating that no values were assigned.  This follows the 
> example of:
> 
>    x,y = []
> 
> But then you'd have to test the return value with empty? and would have 
> to surround the assignment with parentheses, so the syntax becomes much 
> less pleasant.
> 
>     David
> 
>