Probably on my side? ;)

I use it for quick fixes, like at the moment for limiting a tree to certain IDs for testing.

(jQuery EasyUI TreeGrid needs unique IDs per node, I use something like 1_2_3_4 and I don't wanna wait and click thru the whole tree while testing in the browser)

Another example out of many Re: Substitution of a particular letter in all combinations of positions in word (see inside).

but I agree that it's rather on the one-liner/write-once edge of the spectre.

(Due to the limitation to strings and the special syntax)