extend-clj.core — io.github.tonsky/extend-clj 0.1.0

deftype-atom clj/s macro

(deftype-atom name fields & methods)

Allows you to declare new type that will behave like native Clojure Atom, but with custom deref and compare-and-set behaviors. Rest of swap!/reset!/ swap-vals!/reset-vals! will be implemented through these two.

Supports meta/validator/watches and ILookup for fields.

Syntax:

(deftype-atom <name> [<field> ...]
  (deref-impl [this]
    <impl>)
  (compare-and-set-impl [this oldv newv]
    <impl>))

To use this structure, use (-><name> <field> ...) function. E.g. if you

(deftype-atom X [a b c])

then create instances like

(->X a b c)

You can add more interfaces after deref-impl/compare-and-set-impl and implement them as you wish:

(deftype-atom <name> [<field> ...]
  (deref-impl [this]
    <impl>)

  (compare-and-set-impl [this oldv newv]
    <impl>)
  
  clojure.lang.Counted
  (count [this]
    7)
  
  clojure.lang.IBlockingDeref
  (deref [this ms timeout]
    (.deref this)))

Warning: swap-vals! and reset-vals! don’t work in ClojureScript.

IAtom3 clj/s protocol

compare-and-set-impl clj/s

(compare-and-set-impl this oldv newv)

deref-impl clj/s

(deref-impl this)

notify-watches clj/s

(notify-watches this oldv newv)

swap* clj/s

(swap* this f args)

validate clj/s

(validate this validator value)