js--maybe-join

js--maybe-join is a compiled Lisp function in `js.el'.

(js--maybe-join PREFIX SEPARATOR SUFFIX &rest LIST)

Helper function for `js--update-quick-match-re'.
If LIST contains any element that is not nil, return its non-nil
elements, separated by SEPARATOR, prefixed by PREFIX, and ended
with SUFFIX as with `concat'. Otherwise, if LIST is empty, return
nil. If any element in LIST is itself a list, flatten that
element.