refactor code to be more compact

uses alternative branches for failed pattern matches in do-notation

Makefile

@@ -22,6 +22,7 @@ base: prelude
 
 network: prelude
 	make -C libs/network IDRIS2=../../idris2
+	make -C libs/network test IDRIS2=../../idris2
 
 libs : prelude base network
 

libs/network/Echo.idr

@@ -9,70 +9,49 @@ import Network.Socket.Raw
 
 runServer : IO (Either String (Port, ThreadID))
 runServer = do
-  osock <- socket AF_INET Stream 0
-  case osock of
-    Left fail => pure (Left $ "Failed to open socket: " ++ show fail)
-    Right sock => do
-        res <- bind sock (Just (Hostname "localhost")) 0
-        if res /= 0
-          then pure (Left $ "Failed to bind socket with error: " ++ show res)
-          else do
-            port <- getSockPort sock
-            res <- listen sock
-            if res /= 0
-              then pure (Left $ "Failed to listen on socket with error: " ++ show res)
-              else do
-                forked <- fork (serve port sock)
-                pure $ Right (port, forked)
+  Right sock <- socket AF_INET Stream 0
+        | Left fail => pure (Left $ "Failed to open socket: " ++ show fail)
+  res <- bind sock (Just (Hostname "localhost")) 0
+  if res /= 0
+    then pure (Left $ "Failed to bind socket with error: " ++ show res)
+    else do
+      port <- getSockPort sock
+      res <- listen sock
+      if res /= 0
+        then pure (Left $ "Failed to listen on socket with error: " ++ show res)
+        else do
+          forked <- fork (serve port sock)
+          pure $ Right (port, forked)
 
   where
     serve : Port -> Socket -> IO ()
     serve port sock = do
-      res <- accept sock
-      case res of
-        Left err => do
-          putStrLn ("Failed to accept on socket with error: " ++ show err)
-        Right (s, _) => do
-          received <- recv s 1024
-          case received of
-            Left err => do
-              putStrLn ("Failed to accept on socket with error: " ++ show err)
-            Right (str, _) => do
-              putStrLn ("Received: " ++ str)
-              sent <- send s ("echo: " ++ str)
-              case sent of
-                Left err => do
-                  putStrLn ("Server failed to send data with error: " ++ show err)
-                Right n =>
-                  putStrLn ("Server sent " ++ show n ++ " bytes")
+      Right (s, _) <- accept sock
+        | Left err => putStrLn ("Failed to accept on socket with error: " ++ show err)
+      Right  (str, _) <- recv s 1024
+        | Left err => putStrLn ("Failed to accept on socket with error: " ++ show err)
+      putStrLn ("Received: " ++ str)
+      Right n <- send s ("echo: " ++ str)
+        | Left err => putStrLn ("Server failed to send data with error: " ++ show err)
+      putStrLn ("Server sent " ++ show n ++ " bytes")
 
 runClient : Port -> IO ()
 runClient serverPort = do
-  osock <- socket AF_INET Stream 0
-  case osock of
-    Left fail => putStrLn ("Failed to open socket: " ++ show fail)
-    Right sock => do
-      res <- connect sock (Hostname "localhost") serverPort
-      if res /= 0
-        then putStrLn ("Failed to connect client to port " ++ show serverPort ++ ": " ++ show res)
-        else do
-          sent <- send sock ("hello world!")
-          case sent of
-            Left err => do
-              putStrLn ("Client failed to send data with error: " ++ show err)
-            Right n => do
-              putStrLn ("Client sent " ++ show n ++ " bytes")
-              received <- recv sock 1024
-              case received of
-                Left err => do
-                  putStrLn ("Client failed to receive on socket with error: " ++ show err)
-                Right (str, _) => do
-                  putStrLn ("Received: " ++ str)
+  Right sock <- socket AF_INET Stream 0
+    | Left fail => putStrLn ("Failed to open socket: " ++ show fail)
+  res <- connect sock (Hostname "localhost") serverPort
+  if res /= 0
+    then putStrLn ("Failed to connect client to port " ++ show serverPort ++ ": " ++ show res)
+    else do
+      Right n <- send sock ("hello world!")
+        | Left err => putStrLn ("Client failed to send data with error: " ++ show err)
+      putStrLn ("Client sent " ++ show n ++ " bytes")
+      Right (str, _) <- recv sock 1024
+        | Left err => putStrLn ("Client failed to receive on socket with error: " ++ show err)
+      putStrLn ("Received: " ++ str)
 
 main : IO ()
 main = do
-  server <- runServer
-  case server of
-    Left err => putStrLn $ "[server] " ++ err
-    Right (serverPort, tid) => do
-      runClient serverPort
+  Right (serverPort, tid) <- runServer
+    | Left err => putStrLn $ "[server] " ++ err
+  runClient serverPort

libs/network/Makefile

@@ -48,8 +48,8 @@ $(DYLIBTARGET) : $(OBJS)
 	$(CC) -o $(DYLIBTARGET) $(LIBFLAGS) -shared $(OBJS)
 
 install:
-	install $(DYLIBTARGET) $(HDRS) $(TARGET)/idris2/network
 	${IDRIS2} --install network.ipkg
+	install $(DYLIBTARGET) $(HDRS) $(TARGET)/idris2/network
 
 clean :
 	rm -rf $(OBJS) $(LIBTARGET) $(DYLIBTARGET) build