-module(maps_guard_receive).
-export([test/0]).
test() ->
M0 = #{ id => 0 },
Pid = spawn_link(fun() -> guard_receive_loop() end),
Big = 36893488147419103229,
B1 = <<"some text">>,
B2 = <<"was appended">>,
B3 = <<B1/binary, B2/binary>>,
#{id:=1, res:=Big} = M1 = call(Pid, M0#{op=>sub,in=>{1 bsl 65, 3}}),
#{id:=2, res:=26} = M2 = call(Pid, M1#{op=>idiv,in=>{53,2}}),
#{id:=3, res:=832} = M3 = call(Pid, M2#{op=>imul,in=>{26,32}}),
#{id:=4, res:=4} = M4 = call(Pid, M3#{op=>add,in=>{1,3}}),
#{id:=5, res:=Big} = M5 = call(Pid, M4#{op=>sub,in=>{1 bsl 65, 3}}),
#{id:=6, res:=B3} = M6 = call(Pid, M5#{op=>"append",in=>{B1,B2}}),
#{id:=7, res:=4} = _ = call(Pid, M6#{op=>add,in=>{1,3}}),
%% update old maps and check id update
#{id:=2, res:=B3} = call(Pid, M1#{op=>"append",in=>{B1,B2}}),
#{id:=5, res:=99} = call(Pid, M4#{op=>add,in=>{33, 66}}),
%% cleanup
done = call(Pid, done),
ok.
call(Pid, M) ->
Pid ! {self(), M}, receive {Pid, Res} -> Res end.
guard_receive_loop() ->
receive
{Pid, #{ id:=Id, op:="append", in:={X,Y}}=M} when is_binary(X), is_binary(Y) ->
Pid ! {self(), M#{ id=>Id+1, res=><<X/binary,Y/binary>>}},
guard_receive_loop();
{Pid, #{ id:=Id, op:=add, in:={X,Y}}} ->
Pid ! {self(), #{ id=>Id+1, res=>X+Y}},
guard_receive_loop();
{Pid, #{ id:=Id, op:=sub, in:={X,Y}}=M} ->
Pid ! {self(), M#{ id=>Id+1, res=>X-Y}},
guard_receive_loop();
{Pid, #{ id:=Id, op:=idiv, in:={X,Y}}=M} ->
Pid ! {self(), M#{ id=>Id+1, res=>X div Y}},
guard_receive_loop();
{Pid, #{ id:=Id, op:=imul, in:={X,Y}}=M} ->
Pid ! {self(), M#{ id=>Id+1, res=>X * Y}},
guard_receive_loop();
{Pid, done} ->
Pid ! {self(), done};
{Pid, Other} ->
Pid ! {error, Other},
guard_receive_loop()
end.
