Janet preloading

main.janet

(import preloader)

# Files that a use may want to load
(def mod1 (require "mod1"))
(def mod2 (require "mod2"))

(defn main [& args]
  (preloader/preload "@mod1" mod1)
  (preloader/preload "@mod2" mod2)
  (dofile "some-user-file.janet"))

mod1.janet

(def hi "hi")

mod2.janet

(def yo "yo")

preloader.janet

(defn preload
  "Add a module to the preload cache"
  [name env]
  (put module/cache name env))

(defn preload-getter
  "Given a path name, return the module if it is in the cache."
  [x]
  (when (string/has-prefix? "@" x)
    (if (in module/cache x) x)))

(defn preload-loader
  "Just look up a module in the cache."
  [path &]
  (get module/cache path))

(put module/loaders :preload preload-loader)
(array/insert module/paths 0 [preload-getter :preload])

some-user-file.janet

(import @mod1 :as mod1)
(import @mod2 :as mod2)

(mod1/hi)
(mod2/yo)