Is str ~ regex the root of all evil, or the leaf of all good?

[Andrei Alexandrescu]

bearophile wrote:
> Andrei Alexandrescu:
>> auto data = ">hello1 how are5 you?<";
>> auto iter = match(data, regex(r".*?(hello\d).*?(are\d).*"));
>> foreach (i; 0 .. iter.engine.captures)
>>      writeln(iter.capture[i]);
> 
> I don't understand that.
> 
> What's the purpose of ".engine"?

It's the regex engine that has generated the match. I coded that wrong 
in two different ways, it should have been:

foreach (i; 0 .. iter.captures)
       writeln(iter.capture(i));

> "captures" may be better named "ngroups" or "ncaptures", or you may just use the .len/.length attribute in some way.

"Capture" is the traditional term as far as I understand. I can't use 
.length because it messes up with range semantics. "len" would be too 
confusing. "ncaptures" is too cute. Nobody's perfect :o).

> foreach (i, group; iter.groups)
>     writeln(i " ", group);
> 
> "group" may be a struct that defines toString and can be cast to string, and also keeps the starting position of the group into the original string.

That sounds good.


Andrei