js-choi / fnparse Goto Github PK

Upload to clojars.org or make it otherwise leiningen friendly.
Thanks.

project.clj is missing a ]

Just an FYI... I was attempting to run the examples and found that there is a large portion of code wrapped in "comment" in hound.clj -- toward the bottom.
Matt

Hey, guys,

We're using fnparse in Drake, and we're running into some parsing performance and stack issues. Parsing a 15k line source of a very simple structure takes forever (minutes) and fails with stack overflow. I tried to profile it with YourKit Java Profiler, and I'm getting endless stack traces full of monads' m_bind_state_t and m_bind_maybe:

The list of most expensive methods by self-time.

It might be that we're doing something wrong defining grammar. Just in case you want to look at it, it's defined here and here.

We used the JSON parser example as a base, and we use a similar method for updating the current column/line numbers. One observation is that getting rid of column/line tracking reduces parsing time of ~500 line file from 4s to <2s or so. Just that simple change.

We're looking for any advice on how to bring parsing times under control, and also if there's a more efficient method for updating column/line than used in your example.

Thank you!

My project that uses fnparse doesn't compile with Clojure 1.3.0 because fnparse depends on clojure-contrib.accumulators, which in turn depends on clojure.set, which doesn't seem to exist any more.

I just tried doing this:
(def specials-
"~`#$&*()|[]{};'"<>?!")

(def specials
  (apply p/alt (map p/lit specials-)))

But it didn't work, because p/alt is a macro. ("Can't take value of a macro")

For what it's worth, I basically modified your 'alt' macro and put it into my parser:
(defn altarg
[& subrules](monads/with-monad p/parser-m
%28fn [state#]
%28%28apply monads/m-plus subrules%29 state#%29%29))

(def specials-
   "~`#$&*()\\|[]{};'\"<>?!")

(def specials
  (apply altarg (map p/lit specials-)))

and all is well.