Automatic replacement of suggestions

[jpb]

I've created a small plugin that automatically replaces kibit suggestions in source files. Right now it goes something like this:

$ cat your_code.clj
 ...
(+ 1 a)
 ...

$ lein kibit-replace
  Replacing
    (+ 1 a)
   with
    (inc a)
  in your_code.clj:42

$ cat your_code.clj
 ...
(inc a)
 ...

# or 

$ lein kibit-replace --interactive
  Would you like to replace
    (+ 1 a)
   with
    (inc a)
  in your_code.clj:42? [yes/no]

...

Is this something that you would be interested in including in kibit itself?

[danielcompton]

That's great, I'd be very interested in this. How does it handle preserving whitespace/indentation/line splitting?

[jpb]

Great - I'll put together a PR 👍

How does it handle preserving whitespace/indentation/line splitting?

Perserving whitespace, indentation, newlines, and comments is all provided by https://github.com/xsc/rewrite-clj (it looks like it uses a parser combinator, but I haven't dug very much into it https://github.com/xsc/rewrite-clj/blob/master/src/rewrite_clj/parser/core.clj).

[arrdem]

So I haven't pulled out a profiler (yet) but just based on running this plugin I'm deeply suspicious of the performance characteristics of this implementation. When linting clojure.core, it takes about 15-30 seconds of I don't know what idling all my cores (so probably thrashing memory) to discover that (first (next x)) in fnext can be replaced with fnext (which is a false positive but shows how long it takes. That's line 108 in Jaunt. Getting the next change on 117 which is (first (first x)) in ffirst's implementation takes another 15-30 seconds. I fully expect to run this overnight on my really beefy box which is mostly sitting idle.

That said I love this idea and definitely want to see something like this in kibit.

[arrdem]

Update, started linting Jaunt at 12:56am crashed at 6:22am, did not write a result file. I suspect that something to do with the replacement algorithm is at least quadratic on file size.

[danielcompton]

Might be a good candidate for http://accidentallyquadratic.tumblr.com once the issue is found.

[jpb]

@arrdem you are correct in your concern about the performance of kibit-replace - it is definitely quadratic. kibit-replace was mostly a proof of concept - I should advertise it at a such. It re-parses the entire file for each replacement it makes. I've rewritten the algorithm as part of #157 which removes it's quadratic nature.