core.match support

[tatut]

In the example below clj-kondo warns "unresolved symbol a".

(let [v [1 2 3]]
  (m/match v
           [a _ _] (println "first number is " a)
           :else (println "got something other than vector of three")))

[hjhamala]

This should also support core matches or-syntax which currently causes arity error for keyword ->

(let [x 4 y 6 z 9]
(match [x y z]
[(:or 1 2 3) _ _] :a0
[4 (:or 5 6 7) _] :a1
:else nil))

[tatut]

My current plan is to just not lint the pattern part which is its own mini-language.
Only extract bindings from it so that they can be resolved in the consequence part.

[filipesilva]

Note: you can follow https://github.com/borkdude/clj-kondo/blob/master/doc/config.md#exclude-unresolved-symbols-from-being-reported to prevent those symbols from being reported for now.

[mikkosuonio]

Is there something I could do now to prevent an error from the or-keyword?

I get

match-test.cljs:6:14: error: keyword :or is called with 3 args but expects 1 or 2
match-test.cljs:6:26: error: unresolved symbol _
match-test.cljs:7:16: error: keyword :or is called with 3 args but expects 1 or 2

from

(ns match-test
  (:require [cljs.core.match] :as match))

(let [x 4 y 6 z 9]
     (match/match [x y z]
            [(:or 1 2 3) _ _] :a0
            [4 (:or 5 6 7) _] :a1
            :else nil))

using

{:linters {:unresolved-symbol   {:exclude [(clojure.core.match/match)
                                           (cljs.core.match/match)]}}}

[borkdude]

@mikkosuonio Yes, there is a typo in your require spec:

(ns match-test
  {:clj-kondo/config '{:linters {:unresolved-symbol {:exclude [(cljs.core.match/match)]}
                                 :invalid-arity {:skip-args [cljs.core.match/match]}}}}
  (:require [cljs.core.match :as match]))

(let [x 4 y 6 z 9]
  (match/match [x y z]
               [(:or 1 2 3) _ ] :a0
               [4 (:or 5 6 7) _] :a1
               :else nil))

[mikkosuonio]

Thanks for pointing that out!

Config for invalid-arity with skip-args seems to work fine!

[borkdude]

Work in progress in the core-match branch:

[borkdude]

Merged part 1 to master now. Awaiting your feedback.

You can grab a binary from CircleCI / appveyor or use the JVM version.

[borkdude]

And now the final part, part 2 is merged too!