I think you misunderstand what "regex combinators" means. In particular, SRL is not regex combinators.
TAForObvReasons in another answer posted this[1] that would explain it to you.
About your example ... on the contrary, it would become way cleaner with regex combinators. The string manipulation would be replaced with proper composition and the escaping madness would disappear. For example
(concat foo "\\|" bar "\||" baz)
becomes
(alt foo bar baz)
You seem to be familiar with elisp. The lisp family is particularly adapted to combinators approach, please read the link above. :)
If you like regex combinators, check out the elisp "rx" library. You can end up writing code sort of similar to the article's, with less emphasis on using english grammar: http://i.imgur.com/iD34MqC.png
Combinators are very convenient and precise, but the tradeoff is that the code is longer. And I have to look up what to write every time I want to write one. But that's a personal bias.
Thanks for the reference. I'll study it.
EDIT: One of the good ideas in SRL is "if not followed by". There are too many [not]ahead-[not]behind combinations to warrant special syntax for each of them. I wonder if it could be streamlined, though?
If you don't know, SRE is a DSL in scheme that is essentially an alternate syntax for regex that does this, originally implemented by SCSH, and now most popularly by irregex. It looks like this:
[1]: https://groups.csail.mit.edu/mac/users/gjs/6.945/psets/ps01/....
About your example ... on the contrary, it would become way cleaner with regex combinators. The string manipulation would be replaced with proper composition and the escaping madness would disappear. For example
becomes You seem to be familiar with elisp. The lisp family is particularly adapted to combinators approach, please read the link above. :)