et.el

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2. Running the type-checker ​

The type-checker is built in four main layers:

  1. et.el defines the typesystem
  2. et-check.el defines how to type-check elisp code
  3. et-cache.el caches results of expensive computations to improve the checker's performance
  4. et-flymake.el uses flymake to run the type-checker in a background emacs process

To run the checker, clone the repo, then add the following to your config:

emacs-lisp
(add-to-list 'load-path "/path/to/et")
(require 'et-flymake)

Then, navigate to the buffer you want to type-check and run

M-x et-mode

Keep in mind that the checker will only analyze annotated code.

You can also run M-x et-peek to view the inferred type of the expression in front of the point.

emacs-lisp
(et-defun my-fn (x: Number) String
  (make-string (round (* x 10)) ?a))
; │            │      │         ╰──> Literal<97>
; │            │      ╰──> Number
; ╰─> String   ╰──> Integer