teash's Introduction

TEASH

TEA for the shell, in OCaml.

Description

Teash is an interpretation of TEA for the shell, using Lwt and Notty to gain async and terminal rendering capabilities. Use it to build interactive terminal programs that are mostly event driven and organized according to a Model -> Update -> View pattern. Then compile them to either bytecode or native binaries.

Most of the inspiration for this library comes from the excellent bucklescript-tea project.

Installation

opam install teash

Getting started

Make sure to add a reference to the teash library to your build.

A simple Hello world program might look like this:

(* bring Teash into scope *)
open Teash

(* a type to define possible messages/events in the program *)
type msg =
	| Key of Notty.Unescape.key (* this will hold key presses *)

(* initialize the model *)
let init () = ()

(* the central message/event handler *)
let update model = function
	| Key (`Escape, _mods) -> model, App.exit (* listen for ESC and exit *)
	| Key _ -> model, Cmd.none

(* the view is just a function that returns a Notty.image given the model *)
let view _model =
	Notty.(I.string A.(fg red) "Hello World!")

(* hookup subscription to events *)
let subscriptions _model =
	Keyboard.presses (fun key -> Key key) (* subscribe to key presses and map to our msg type *)

(* "main" *)
let () =
	App.run {
		init;
		update;
		view;
		subscriptions;
		shutdown = (fun _model -> ());
	} ()