Whats is ->, ->> , ^ :private, s/def s/defn and : - in Clojure

Question

Sincerelly, I read a lot of times about this commands and I don't understand what the real objectives. I'm reading pedestal documentation and I saw a lot of this command -> and ->> and I read in nubank's github public repository somethings as ^:private, s/def, s/defn and :-

Answer 1

You should go through a Clojure tutorial first to understand meaning of basic constructs and symbols. These resources can help

• https://clojure.org/guides/learn/clojure
• https://aphyr.com/tags/clojure-from-the-ground-up
• https://clojure.org/guides/weird_characters

In short,

• -> and ->> are threading macros
• s/def depends on what s refers to - it is commonly use as an alias for clojure.spec.alpha and s/def is then used to define a spec: https://clojure.org/guides/spec
  • However, there's no clojure.spec.alpha/defn so in that case it's probably another "schema library"; it would help if you linked the source you are talking about
• ^:private is a metadata key that marks a symbol as private within a given namespace; see also http://blogish.nomistech.com/two-ways-of-defining-private-functions/