edtris/lib/stdio.fnl
2021-02-07 16:56:19 -05:00

47 lines
1.8 KiB
Fennel

(require "love.event")
(local view (require "lib.fennelview"))
;; This module exists in order to expose stdio over a channel so that it
;; can be used in a non-blocking way from another thread.
(local (event channel) ...)
(when channel
(let [prompt (fn [] (io.write "> ") (io.flush) (io.read "*l"))]
((fn looper [input]
(when input
;; This is consumed by love.handlers[event]
(love.event.push event input)
(let [output (: channel :demand)]
;; There is probably a more efficient way of determining an error
(if (and (. output 2) (= "Error:" (. output 2)))
(print (view output))
(each [_ ret (ipairs output)]
(print ret))))
(io.flush)
(looper (prompt)))) (prompt))))
{:start (fn start-repl []
(let [code (love.filesystem.read "lib/stdio.fnl")
luac (if code
(love.filesystem.newFileData
(fennel.compileString code) "io")
(love.filesystem.read "lib/stdio.lua"))
thread (love.thread.newThread luac)
io-channel (love.thread.newChannel)
coro (coroutine.create fennel.repl)
out (fn [val]
(: io-channel :push val))
options {:readChunk coroutine.yield
:onValues out
:onError (fn [kind ...] (out [kind "Error:" ...]))
:pp view
:moduleName "lib.fennel"}]
;; this thread will send "eval" events for us to consume:
(coroutine.resume coro options)
(: thread :start "eval" io-channel)
(set love.handlers.eval
(fn [input]
(coroutine.resume coro (.. input "\n"))))))}