The parser for patterns seems not quite right; specifically there seems to be a problem with backlashes. Consider this example:

(Pattern.substitute #"\b" "w\b" "\\\\b" -1) ; => throws an error about an unexpected quote
(Pattern.substitute &(Pattern.init "\b") "w\b" "\\\\b" -1) ; => works fine

(This is courtesy of the famous, revered, and all around great guy @TimDeve)

I volunteer to look into this.

Cheers