Clojurians Log v2

(m/rewrite {:a "a"
            :b [{:name "pickname" :value "foo"} {:name "somthingelse" :value "bar"}]}
  {:a ?a
   :b [{:value !value} ...]}
  [{:my/a ?a
    :my/b !value} ...])
;; => [#:my{:a "a", :b "foo"} #:my{:a "a", :b "bar"}]

Wait, I misread

You want to get whatever has pickme

right.

i got something sorta working with cata

(m/rewrite {:a "a"
            :b [{:name "pickme" :value "foo"} {:name "somthingelse" :value "bar"}]}
  {:a ?a
   :b (m/scan {:name "pickme" :value !value})}
  {:my/a ?a
   :my/b !value})

;; => #:my{:a "a", :b "foo"}

ok cool i thought i tried that but at this point who knows lol

one sec

ah i was using match instead of rewrite

ugh

thx!

Scan does not work with match, but with find it does.

(m/find {:a "a"
            :b [{:name "pickme" :value "foo"} {:name "somthingelse" :value "bar"}]}
  {:a ?a
   :b (m/scan {:name "pickme" :value !value})}
  {:my/a ?a
   :my/b !value})

gotcha. still working through what works with what lol

and if you don't need to collect multiple values, it's a better idea to use ?value instead of !value

The learning curve of meander is very steep, I recommend to start with find, only after that play with rewrite, and finally recursion with cata and with

yeah that’s what threw me a little

because i know i wanted a single value ?… but in that context most of the examples are the memory vars !..

gotca

will use that heuristic going forward

memory vars will always work too, but they are obviously slower

i’ll maybe add that to the docs lol. because it seems simple for a lot of common cases but, yeah there are quite a few dangerous left turns lol

@eoliphant I merge 100% of patches to our docs. 🙂