Exercise 4-1: An Echo Server

[pugsley]

Hi,

Here's my solution for Exercise 4-1: An Echo Server.

%% Erlang Programming
%% Exercise 4-1: An Echo Server
-module(echo).
-export([start/0,print/1,stop/0]).
-export([loop/0]).

start() ->
register(echo, spawn(echo, loop, [])),
ok.

print(Msg) ->
echo ! {print, Msg},
ok.

stop() ->
echo ! stop,
ok.

loop() ->
receive
{print, Msg} ->
io:format("~w~n", [Msg]),
loop();
stop ->
true
end.

[Nataly]

An error occurs during the execution this code.

=ERROR REPORT==== 27-Nov-2012::16:23:39 ===
Error in process <0.44.0> with exit value: {undef,[{echo,loop,[],[]}]}

I don't understand why. Could you please help me.

[Simon Thompson]

This may well be because you didn't export the loop function from the echo module.

Simon

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Simon Thompson | Professor of Logic and Computation 
School of Computing | University of Kent | Canterbury, CT2 7NF, UK
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[Nataly]

Thank you for your answer. I found an error. I renamed the module -module(echo3), but forgot to change the string register(echo, spawn(echo, loop, [])).

вторник, 27 ноября 2012 г., 20:13:04 UTC+4 пользователь Simon Thompson написал: