Implement protocols

[borkdude]

Work in progress in the defprotocol branch.

Todo:

• defprotocol
• extend-protocol
• defrecord + protocols
• extend
• extend-type
• support docstring in defprotocol:

(defprotocol Fly
  "A simple protocol for flying"
  (fly [this] "Method to fly"))

• extends?
• fully qualify protocol symbols / test with different namespaces
• instance? should work on protocol checks: (instance? clojure.spec.alpha.Spec x)
• test more examples from clojuredocs
• test libs: spec, hiccup

[cldwalker]

I think this would be valuable as I've tried using a couple libraries in bb scripts and found the lack of protocol prevented their usage. https://github.com/clj-commons/camel-snake-kebab was one I tried

[cldwalker]

Three more namespaces/libraries that would be great to have if defprotocol is available:

• clojure.datafy
• https://github.com/aysylu/loom via Support java.util.Arrays/copyOf babashka#415
• org.clojure/test.check

[borkdude]

Another library with defprotocol: https://github.com/clojure/tools.namespace
See babashka/babashka#424

[borkdude]

Made some progress in the defprotocol branches of babashka and sci.

• The camel-snake-kebab library now fully works.
• The loom.graph namespace works, but .alg doesn't because it depends on the priority-map library which uses deftype.
• tools.namespace:

user=> (require '[clojure.tools.namespace.find :as f])
: Unable to resolve classname: java.net.URLClassLoader [at clojure/java/classpath.clj, line , column ]

This class isn't supported by GraalVM afaik.

test.check:

user=> (require '[clojure.test.check :as tc])
: Could not resolve symbol: *unchecked-math* [at clojure/test/check/random.clj, line 92, column 7]

After solving that problem, I hit deftype.

[cldwalker]

@borkdude Confirmed all the same behaviors in the above libraries with 0.1.1. Thanks! To get closer to test.check working, I could add the *unchecked-math* binding to main.clj if you'd like

[borkdude]

Sure, go ahead.