ludus/clj_to_janet.md

From Clojure to Janet

How to convert files

Comments

% s ; r # <esc>

called keyword property access

Use a macro:

• Select \ \( : ret <esc>
• Record the macro: Q n <esc> v e c get <esc> e e a <space> <esc> p <esc> Q
• Then just q until you've changed everything

Chars don't exist

• \char -> "char", e.g.
• \newline -> "\n", etc.
• \a -> "a"

Use mutable arrays and tables

Where data structures are mutable, add @s.

Sets & tables

Sets don't exist in Janet. Use tables with values set to true.

Strings -> number literals

• Clj uses edn/read-string; Janet uses parse-all

loop -> defn recur

• Clj's loop is very different from Janet's loop
• As a quick and dirty workaround, change it to an interior recursive function
• Janet has tail calls, so this is nearly as efficient (paying the overhead for creating the function)
• An optimization is to pull out these functions and declare them at the toplevel

current-char

Straight replacements:

• nth -> get
• assoc -> put
• conj -> array/push
• str -> string
• substr -> slice