balanced.clj

(def bal
  (insta/parser
    "expr = group
     <cmd> = word (space word)*
     sub-expr = <dollar> <lparen> group <rparen>
     <group> = lparen cmd rparen | cmd
     <word> = sub-expr | group | #'[^ ()]*'
     space = <' '>+
     <dollar> = '$'
     <lparen> = '('
     <rparen> = ')'
     "))

(bal "(foo (bar))")
(bal "foo bar (bar)")
(bal "foo bar $(baz bar)")

(bal "foo bar (qux) $(clj (map (partial * 2) (range 10)))")
[:expr "foo" [:space] "bar" [:space] "(" "qux" ")" [:space] [:sub-expr "clj" [:space] "(" "map" [:space] "(" "partial" [:space] "*" [:space] "2" ")" [:space] "(" "range" [:space] "10" ")" ")"]]