How to make a clojure library self host compatible

In order to make a clojure library self host compatible, you need first to port it to cljc and then make it self-host compatible.

From Clojure to ClojureScript

• rename files from .clj to .cljc
• use #?(:cljs ... :clj) when a different code is needed for clojure and clojurescript
• move the macros into a .clj file

From ClojureScript to Self-host compatible

Planck

• install planck
• move to the main folder of your library
• Launch planck with the correct classpath:

    planck -c`lein classpath`

• require the namespaces of your libray
• fix the bugs
• test again

Once you are done push the code to github and test online with KLIPSE.

KLIPSE

• Open the KLIPSE REPL with external-data-libs=[<your raw github root>] e.g. http://app.klipse.tech/?external-libs=[https://raw.githubusercontent.com/viebel/math.combinatorics/master/src/main/clojure/]
• require the namespaces of your libray
• fix the bugs and re-push
• test again

Coding the port

Reader conditionals

In self-host, reader conditionals always branch to :cljs.

Data Types and protocols

Clojure and Clojurescript data types and protocols are very different

Macros

Macro code must be put in a separate file - .clj or .cljc

Debugging

It's hard!