Added some more server socket fun and examples. (0.27.0)

CMakeLists.txt

@@ -1,5 +1,5 @@
-cmake_minimum_required(VERSION 3.16)
-project(fun VERSION 0.26.6 LANGUAGES C)
+cmake_minimum_required(VERSION 3.5)
+project(fun VERSION 0.27.0 LANGUAGES C)
 
 set(CMAKE_C_STANDARD 99)
 set(CMAKE_C_STANDARD_REQUIRED ON)

examples/debug_reporting.fun

@@ -1,4 +1,15 @@
-//!/usr/bin/env fun
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-10-06
+ */
 
 /*
  * Debugging and error reporting demo for Fun.

examples/extra/tcp_echo_server.fun

@@ -0,0 +1,37 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-10-13
+ */
+
+// Simple TCP echo server using built-in socket ops.
+// Listens on localhost:12345 and echoes a single line/request back to each client.
+
+port = 12345
+backlog = 16
+
+listen_fd = tcp_listen(port, backlog)
+if (listen_fd <= 0)
+  print("tcp_listen failed")
+  exit(1)
+
+print("Echo server listening on port " + to_string(port))
+
+while (true)
+  client = tcp_accept(listen_fd)
+  if (client > 0)
+    data = sock_recv(client, 4096)
+    if (len(data) > 0)
+      // Echo back exactly what we received
+      sock_send(client, data)
+    sock_close(client)
+
+// Not reached in this example, but here for completeness
+sock_close(listen_fd)

examples/extra/tcp_echo_server_class.fun

@@ -0,0 +1,32 @@
+#!/usr/bin/env fun
+
+/*
+ * This file is part of the Fun programming language.
+ * https://fun-lang.xyz/
+ *
+ * Copyright 2025 Johannes Findeisen <you@hanez.org>
+ * Licensed under the terms of the Apache-2.0 license.
+ * https://opensource.org/license/apache-2-0
+ *
+ * Added: 2025-10-13
+ */
+
+// Echo server using the stdlib TcpServer class.
+// Make sure FUN_LIB_DIR points to the ./lib directory containing io/socket.fun.
+// Example:
+//   FUN_LIB_DIR="$(pwd)/lib" ./build/fun ./examples/tcp_echo_server_class.fun
+
+include <io/socket.fun>
+
+print("Starting echo server at localhost:12345")
+
+server = TcpServer(12345, 16)
+
+if (server.listen() <= 0)
+  print("Listen failed!")
+  exit(1)
+else
+  print("Echo server (class) listening on port 12345")
+
+// Serve clients forever, echoing back what they send.
+server.serve_forever(4096)

lib/io/socket.fun

@@ -25,7 +25,6 @@
  *     print(resp)
  *     c.close()
  */
-
 class TcpClient()
   // file descriptor or 0 if not connected
   fd = 0
@@ -72,6 +71,48 @@ class TcpClient()
       this.fd = 0
     return 1
 
+// TcpServer: simple wrapper around TCP socket built-ins.
+// Exposes listen(), accept(), echo_once(maxlen), serve_forever(maxlen), close().
+class TcpServer(number port, number backlog)
+
+  fun _construct(this, port, backlog)
+    this.port = port
+    this.backlog = backlog
+    this.listen_fd = 0
+
+  fun listen(this)
+    this.listen_fd = tcp_listen(this.port, this.backlog)
+    return this.listen_fd
+
+  fun accept(this)
+    return tcp_accept(this.listen_fd)
+
+  fun close(this)
+    if (this.listen_fd > 0)
+      sock_close(this.listen_fd)
+      this.listen_fd = 0
+
+  fun echo_once(this, maxlen)
+    c = this.accept()
+    if (c <= 0)
+      return 0
+
+    data = sock_recv(c, maxlen)
+    if (len(data) > 0)
+      sock_send(c, data)
+
+    sock_close(c)
+    return 1
+
+  fun serve_forever(this, maxlen)
+    if (this.listen_fd <= 0)
+      if (this.listen() <= 0)
+        print("TcpServer: listen failed on port " + to_string(this.port))
+        return 0
+      print("TcpServer: listening on port " + to_string(this.port))
+    while (true)
+      this.echo_once(maxlen)
+
 class UnixClient()
   fd = 0