Added some basic asyncio stuff. (0.39.12)

examples/io/async_http_client.fun

@@ -0,0 +1,91 @@
+#!/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: 2026-03-26
+ */
+
+/*
+ * Async-ish HTTP GET using new FD helper opcodes
+ *
+ * Demonstrates:
+ * - tcp_connect(host, port)
+ * - fd_set_nonblock(fd, on)
+ * - fd_poll_write(fd, timeout_ms) and fd_poll_read(fd, timeout_ms)
+ * - non-blocking send/recv loop
+ */
+
+host = "example.org"
+port = 80
+
+fd = tcp_connect(host, port)
+if (fd == 0)
+  print("connect failed")
+  exit(1)
+
+ok = fd_set_nonblock(fd, 1)
+if (ok == 0)
+  print("failed to set nonblocking")
+  sock_close(fd)
+  exit(1)
+
+req = "GET / HTTP/1.1\r\nHost: " + host + "\r\nConnection: close\r\n\r\n"
+to_send = len(req)
+sent_total = 0
+
+// Write request in a non-blocking fashion
+while (sent_total < to_send)
+  // Wait until socket is writable (timeout 1000ms)
+  wr = fd_poll_write(fd, 1000)
+  if (wr < 0)
+    print("poll write error")
+    sock_close(fd)
+    exit(1)
+  if (wr == 0)
+    // timeout, loop again
+    continue
+
+  chunk = substr(req, sent_total, to_send - sent_total)
+  n = sock_send(fd, chunk)
+  if (n < 0)
+    print("send error")
+    sock_close(fd)
+    exit(1)
+  sent_total = sent_total + n
+
+// Read response non-blocking until peer closes
+buf = ""
+while (true)
+  rd = fd_poll_read(fd, 2000) // wait up to 2s for data
+  if (rd < 0)
+    print("poll read error")
+    break
+  if (rd == 0)
+    // timeout or EOF; try a final read to see if closed
+    data = sock_recv(fd, 4096)
+    if (len(data) == 0)
+      // assume connection closed
+      break
+    buf = buf + data
+    continue
+
+  data = sock_recv(fd, 4096)
+  if (len(data) == 0)
+    // closed
+    break
+  buf = buf + data
+
+sock_close(fd)
+
+// Print the first lines of the response to show it's working
+print(substr(buf, 0, 200))
+
+/*
+Expected: prints the beginning of an HTTP response from example.org
+*/