Exercises in http://www.erlang.org/course/exercises.html

concurrent1.erl

-module(concurrent1).
-export([pong/0, ping/1, start/1]).

pong() ->
    receive
        {From, Msg} ->
            io:format("Pong received ~w~n", [Msg]),
            From ! {self(), Msg},
            pong();
        term ->
            io:format("Bye~n", [])
    end.

ping(0) ->
    pongProc ! term,
    io:format("Bye~n", []);
ping(M) ->
    pongProc ! {self(), hello},
    receive
        {From, Msg} ->
            io:format("Ping received ~w~n", [Msg])
    end,
    ping(M - 1).

start(M) ->
    PongPid = spawn(concurrent1, pong, []),
    register(pongProc, PongPid),
    spawn(concurrent1, ping, [M]).

list1.erl

-module(list1).
-export([min/1, max/1, min_max/1]).

min([Head | Rest]) ->
    min_(Rest, Head).

max([Head | Rest]) ->
    max_(Rest, Head).

min_([], Result) ->
    Result;
min_([Head | Rest], ResultSoFar) when ResultSoFar > Head ->
    min_(Rest, Head);
min_([_ | Rest], ResultSoFar) ->
    min_(Rest, ResultSoFar).

max_([], Result) ->
    Result;
max_([Head | Rest], ResultSoFar) when ResultSoFar < Head ->
    max_(Rest, Head);
max_([_ | Rest], ResultSoFar) ->
    max_(Rest, ResultSoFar).

min_max(List) ->
    {list1:min(List), list1:max(List)}.

temp.erl

-module(temp).
-export([convert/1]).

f2c(F) ->
    5 * (F - 32) / 9.

c2f(C) ->
    9 * C / 5 + 32.

convert({c, X}) ->
    {f, c2f(X)};
convert({f, Y}) ->
    {c, f2c(Y)}.