parse quoted strings with instaparse

instaquote.clj

;;see http://stackoverflow.com/questions/16215169/clojure-csv-with-escaped-comma

(require '[instaparse.core :as insta])

((insta/parser
  "quoted-field = <'\\\"'> (#'[^\"\\\\]+' | escaped-char)* <'\\\"'>
  <escaped-char> = #'\\\\.'") "\"hello\\\" world\"")

;;and to parse comments like /** this is a test */
;;http://stackoverflow.com/questions/11125459/java-regex-negative-lookahead

;;positive lookahead
(def comment-parser
  (insta/parser "comment = <'/**'> #'.+(?=\\*\\*/)' <'**/'>"))

;;with negative lookahead it's more complicated
(def comment-parser
  (insta/parser "comment = <'/**'> #'.+?(?!.+\\*\\*/)' <'**/'>"))

;;user> (comment-parser "/** this is a test **/")
;;[:comment " this is a test "]

;;or https://github.com/Engelberg/instaparse/blob/master/docs/ExperimentalFeatures.md#auto-whitespace

(def comment-parser2
  (insta/parser
   "comment = <'/**'> inside-comment* <'**/'>
    <inside-comment> = !('**/'|'/**') #'.'"))

;;user>(comment-parser2 "/**this is a test**/")
;;[:comment "t" "h" "i" "s" " " "i" "s" " " "a" " " "t" "e" "s" "t"]