122 lines
2.7 KiB
Standard ML
Executable file
122 lines
2.7 KiB
Standard ML
Executable file
#!/usr/bin/env fun
|
|
|
|
/*
|
|
* This file is part of the Fun programming language.
|
|
* https://fun-lang.xyz/
|
|
*
|
|
* Copyright 2026 Johannes Findeisen <you@hanez.org>
|
|
* Licensed under the terms of the Apache-2.0 license.
|
|
* https://opensource.org/license/apache-2-0
|
|
*
|
|
* Added: 2026-03-29
|
|
*/
|
|
|
|
/*
|
|
* Async-style HTTP GET using lib/async/scheduler.fun helpers
|
|
*
|
|
* This demonstrates building an "await-like" workflow without VM-level
|
|
* async/await. We use a cooperative task that advances a small state
|
|
* machine each tick, calling await_write/await_read to probe readiness.
|
|
*/
|
|
|
|
#include <async/scheduler.fun>
|
|
|
|
host = "example.org"
|
|
port = 80
|
|
|
|
// Task state and step function
|
|
fun http_get_step(t)
|
|
// phases: 0=connect, 1=set nonblock, 2=send, 3=recv, 4=done
|
|
if (t.phase == nil)
|
|
t.phase = 0
|
|
|
|
if (t.phase == 0)
|
|
t.fd = tcp_connect(host, port)
|
|
if (t.fd == 0)
|
|
print("connect failed")
|
|
t.done = 1
|
|
return
|
|
t.phase = 1
|
|
return
|
|
|
|
if (t.phase == 1)
|
|
ok = fd_set_nonblock(t.fd, 1)
|
|
if (ok == 0)
|
|
print("failed to set nonblocking")
|
|
sock_close(t.fd)
|
|
t.done = 1
|
|
return
|
|
t.req = "GET / HTTP/1.1\r\nHost: " + host + "\r\nConnection: close\r\n\r\n"
|
|
t.sent = 0
|
|
t.phase = 2
|
|
return
|
|
|
|
if (t.phase == 2)
|
|
// send request in chunks when writable
|
|
if (t.sent < len(t.req))
|
|
// short timeout to keep loop responsive
|
|
wr = await_write(t.fd, 50)
|
|
if (wr < 0)
|
|
print("poll write error")
|
|
sock_close(t.fd)
|
|
t.done = 1
|
|
return
|
|
if (wr == 0)
|
|
// not yet writable; yield to others
|
|
return
|
|
chunk = substr(t.req, t.sent, len(t.req) - t.sent)
|
|
n = sock_send(t.fd, chunk)
|
|
if (n < 0)
|
|
print("send error")
|
|
sock_close(t.fd)
|
|
t.done = 1
|
|
return
|
|
t.sent = t.sent + n
|
|
return
|
|
// all sent; switch to receive
|
|
t.buf = ""
|
|
t.phase = 3
|
|
return
|
|
|
|
if (t.phase == 3)
|
|
rd = await_read(t.fd, 100)
|
|
if (rd < 0)
|
|
print("poll read error")
|
|
sock_close(t.fd)
|
|
t.phase = 4
|
|
t.done = 1
|
|
return
|
|
if (rd == 0)
|
|
// try a small read to detect close, else wait more
|
|
data = sock_recv(t.fd, 4096)
|
|
if (len(data) == 0)
|
|
sock_close(t.fd)
|
|
t.phase = 4
|
|
t.done = 1
|
|
return
|
|
t.buf = t.buf + data
|
|
return
|
|
// readable
|
|
data = sock_recv(t.fd, 4096)
|
|
if (len(data) == 0)
|
|
sock_close(t.fd)
|
|
t.phase = 4
|
|
t.done = 1
|
|
return
|
|
t.buf = t.buf + data
|
|
return
|
|
|
|
if (t.phase == 4)
|
|
// print first 200 chars and finish
|
|
print(substr(t.buf, 0, 200))
|
|
t.done = 1
|
|
return
|
|
|
|
|
|
// Spawn task and run
|
|
task = task_spawn(http_get_step, {})
|
|
run_until_done()
|
|
|
|
/*
|
|
Expected: prints the beginning of an HTTP response from example.org
|
|
*/
|