lecture 07

lectures/07/arith.erl

@@ -0,0 +1,28 @@
+-module(arith).
+-export([start/0, square/2, sqrt/2]).
+
+start() ->
+	{ok, _Pid} = spawn(fun loop/0).
+
+square(Pid, N) ->
+	Pid ! {square, self(), N},
+	receive
+		{Pid, Reply} -> Reply
+	end.
+
+sqrt(Pid, N) ->
+	Pid ! {sqrt, self(), N},
+	receive
+		{Pid, Reply} -> Reply
+	end.
+
+loop() ->
+	receive
+		{square, From, N} ->
+			From ! {self(), N * N};
+		{sqrt, From, N} when N < 0 ->
+			From ! {self(), error};
+		{sqrt, From, N} ->
+			From ! {self(), math:sqrt(N)}
+	end,
+	loop().