cleaned up the set of samples

samples/tcp-server.noja

@@ -0,0 +1,108 @@
+# Implementation of a basic TCP server that listen for connections and prints received bytes.
+
+fun startServer(callbacks, port, backlog)
+{
+	# Handle default arguments.
+	{
+		if callbacks == none:
+			callbacks = {};
+
+		if port == none:
+			port = 8000;
+
+		if backlog == none:
+			backlog = 5;
+	}
+
+	fd = net.socket(net.AF_INET, net.SOCK_STREAM, 0);
+	
+	if fd < 0:
+		{
+			print('Failed to create socket.\n');
+			return none;
+		}
+
+	if net.bind(fd, {
+			sin_family: net.AF_INET, 
+			sin_port: net.htons(port), 	
+			sin_addr: {
+				s_addr: net.htonl(net.INADDR_ANY)
+			}
+		}) != 0:
+		{
+			print('Failed to bind.\n');
+			return none;
+		}
+
+	if net.listen(fd, backlog) != 0:
+		{
+			print('Failed to listen.\n');
+			return none;
+		}
+
+	{
+		on_datain     = callbacks.on_datain;
+		on_connect    = callbacks.on_connect;
+		on_disconnect = callbacks.on_disconnect;
+
+		if on_datain == none: 
+			fun on_datain() 
+				none;
+
+		if on_connect == none: 
+			fun on_connect() 
+				none;
+		
+		if on_disconnect == none: 
+			fun on_disconnect() 
+				none;
+	}
+
+	buffer = newBuffer(1024);
+
+	while true:
+		{
+			client_addr = {};
+			client_fd   = net.accept(fd, client_addr);
+
+			if client_fd < 0:
+				{
+					print('Warning! Failed to accept!\n');
+					continue;
+				}
+
+			addr_str = net.inet_ntoa(client_addr.sin_addr);
+			
+			on_connect(addr_str);
+
+			do 
+				{
+					n = net.recv(client_fd, buffer, 0);
+
+					if n < 0:
+						print('Warning! Failed to read from socket!\n');
+					else if n == 0:
+						on_disconnect(addr_str);
+					else
+						on_datain(addr_str, sliceBuffer(buffer, 0, n));
+				}
+			while n > 0;
+		}
+}
+
+fun on_connect(addr)
+{
+	print(addr, ' connected.\n');
+}
+
+fun on_datain(addr, data)
+{
+	print('Received ', count(data), ' bytes from ', addr, ': ', data, '\n');
+}
+
+fun on_disconnect(addr)
+{
+	print(addr, ' disconnected.\n');
+}
+
+startServer({on_connect: on_connect, on_datain: on_datain, on_disconnect: on_disconnect}, 8080);