rontolisp.wit/export

(export "path.wit") or (export "path.wit" {:world "name"}) with [rontolisp.wit :as wit]

Declares that the program implements a WIT world: each export of the world is the var its label names in the current namespace -- a defn defined anywhere in the file, a referred var -- and the module exports it with the world's types (WIT contracts). :world names the world when the file declares several. The WIT file is relative to the file naming it, like load.

$ cat wit/greeter.wit
package example:greeter@0.1.0;

world greeter {
  export greet: func(name: string) -> string;
  export is-short: func(name: string) -> bool;
}
$ cat greeter.clj
(ns greeter (:require [rontolisp.wit :as wit]))

(wit/export "wit/greeter.wit")

(defn greet [name] (str "Hello, " name "!"))
(defn is-short [name] (< (count name) 5))
$ rontolisp greeter.clj -o greeter.wasm --component --emit-wit
$ wasmtime run --invoke 'is-short("Grace")' greeter.wasm
false

The world is the program's whole export list: a rontolisp.wasm/export beside it is refused. The world is checked when the program compiles, on every target -- an export naming no var, a defn with no arity taking its parameters, a type the export boundary does not carry, an async func -- each refused naming the WIT line. A bool crosses as true or false, and an export that is no single-arity defn taking exactly its parameters goes through a function of that arity calling the var, as for rontolisp.wasm/export. --emit-wit writes the world back, parameter names included.

In a REPL, a world is checked against what is defined so far: define its functions first.