For instance, say we're looking at a query string, all-lowercase, all non-numeric, no special character (just [a-z] and =):
?some=querystring&ssembly=containing&n=indeterminate&mount=of&ll=potentially&ccordant=matches
Let us take as a given we know there will be three key-value pairs we wish to capture, and even that they are located at the beginning of said string:
some=querystringssembly=containingn=indeterminateNow, intuitively, it seems like I should be able to use something like...
^\?(&?[a-z=]+){3}.*$
...or possibly...
^\?(?:&?([a-z=]+)){3}.*$
...but, of course, the only capture this yields is
n=indeterminate
Is there a syntax that would allow me to capture all three groups (as independent, accessible values, natch) without having to resort to the following?
^\?([a-z=]+)&([a-z=]+)&([a-z=]+).*$
I know there's no way to capture n instances (an arbitrarily-large set), but, given this is a finite number of captures I wish to obtain from my finite automata...
I know full well there are any number of ways to accomplish this in Javascript, or any other language for that matter. I'm specifically trying to ascertain if I'm stuck with the WET expression above.
There's no recursion in EcmaScript regular expressions. Reference documentation is here, you'll see there's no recursion operator. You can also check regular-expressions.info; it tells which engines support recursion: Perl 5.10, PCRE 4.0, Ruby 2.0, Delphi, PHP, and R.