Clojurians Log v2
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meander
David G 2022-11-04T19:55:57.107169Z
I’m trying to mimic Clojure’s update but I’m struggling to understand how to do sort of in-place updates to maps using match:
(m/match {:a 1 :b 3}
{:a ?a & _}
{:a (inc ?a)
????})inc only on :a (and perhaps do that for several other keywords, but this is the basic form of what I’m trying to do).
How do you stitch back the “rest” of the map?
jgdavey 2022-11-04T19:58:26.051339Z
Perhaps you want m/rewrite?
`
David G 2022-11-04T19:59:03.197799Z
I thought rewrite outputs a match pattern given an input which you can match against
jgdavey 2022-11-04T19:59:11.753449Z
(m/rewrite {:a 1 :b 3}
{:a ?a & ?m}
{:a (m/app inc ?a) & ?m})jgdavey 2022-11-04T20:01:11.530539Z
rewrite’s “action” branch is pattern-like, as opposed to match/search/find which are more like literal clojure
David G 2022-11-04T20:05:05.446479Z
“action” is the second parameter in this case, right?