Week 50: What did you learn this week?

plexus · December 11, 2017, 8:43am

What Clojure, programming, or life skill did you learn this week?

DjebbZ · December 11, 2017, 8:45pm

Combining reader conditional macro #?(:clj) and splicing. Example #?@(:clj [1 2 3]). It’s documented officially here but I stumbled upon this in rum’s source to group clj deps and cljs deps in the ns macro. Clever and more readable !

glts · December 12, 2017, 5:47pm

While reading some Clojure code yesterday I learned that Clojure allows you to be quite creative with var names …

github.com

pjstadig/reducible-stream/blob/fd2e3a42cb570e2326cd631eb0e8237b95d4527b/src/pjstadig/reducible_stream.clj#L158


clojure-open, and all other options are passed along to clojure.core/read.  If
the :encoding option is not specified, it will default to \"UTF-8\"."
([stream]
 (decode-clojure! {} stream))
([options stream]
 (cond-> (decode! (bound-fn* (partial clojure-decoder (dissoc options :encoding)))
                  {:open (partial clojure-open (:encoding options))}
                  stream)
   (contains? options :eof) (concat [(:eof options)]))))


(defn- transit-enabled‽
[]
(require 'cognitect.transit))


(defn transit-open
"Used as the open function for decoding transit.  Passes along options to
cognitect.transit/reader, and returns a transit reader for use with
cognitect.transit/read."
[type options stream]
(transit-enabled‽)
(let [reader (ns-resolve 'cognitect.transit 'reader)]

Yes, that’s transit-enabled‽. I shouldn’t but I like this

plexus · December 12, 2017, 6:11pm

Don’t we all love a good interrobang‽ Note though that as far as I know using random unicode in var names is not officially supported, and it does not work in ClojureScript. It does happen to work fine in Clojure.

It’s a surprisingly hard question of what is or isn’t a valid symbol in Clojure or EDN. The EDN spec says one thing, but implementations are all a little different.

system · October 5, 2018, 12:50pm