Erlang basic general server debugger output interpretation -

Erlang basic general server debugger output interpretation -

i'm having problem erlang module. here 1 wrote:

-module(basic_gen_server). -export([start/1, call/2, cast/2]).

start(module) -> register(server, spawn(basic_gen_server,gen_server_loop,[module, module:init()])), server. call(pid,request) -> pid ! {call, self(), request}, receive reply -> reply end. cast(pid,request) -> pid ! {cast, self(), request}, receive _ -> ok end. gen_server_loop(module, currentstate) -> io:fwrite("gen_server_loop~n", []), receive {call, callpid, request} -> {reply, reply, newstate} = module:handle_call(request,self(),currentstate), callpid ! reply, gen_server_loop(module, newstate); {cast, castpid, request} -> {noreply, newstate} = module:handle_cast(request, currentstate), castpid ! noreply, gen_server_loop(module, newstate) end.

and here callback module defined:

% written caleb helbling % lastly updated oct 10, 2014 -module(name_server). -export([init/0, add/3, whereis/2, handle_cast/2, handle_call/3, handle_swap_code/1]). %% client routines add(serverpid, person, place) -> basic_gen_server:cast(serverpid, {add, person, place}). whereis(serverpid, person) -> basic_gen_server:call(serverpid, {whereis, person}). %% callback routines init() -> maps:new(). handle_cast({add, person, place}, state) -> newstate = maps:put(person, place, state), {noreply, newstate}. handle_call({whereis, person}, _from, state) -> reply = case maps:find(person, state) of {ok, place} -> place; error -> error end, newstate = state, {reply, reply, newstate}. handle_swap_code(state) -> {ok, state}.

upon trying initialize server next command:

myserver = basic_gen_server:start(name_server).

i next debug output:

=error report==== 29-oct-2014::12:41:42 === error in process <0.70.0> exit value: {undef,[{basic_gen_server,gen_server_loop,[name_server,#{}],[]}]}

conceptually, understand notion of making serial code basic server system, believe have syntax error haven't been able find using either syntax highlighting or google. in advance help!

function gen_server_loop not exported. can not phone call basic_gen_server:gen_server_loop(module, module:init()), happening within spawn(basic_gen_server,gen_server_loop,[module, module:init()]).

if read error message tells function trying phone call in undefined (trougn undef atom). function beingness {basic_gen_server,gen_server_loop,[name_server,#{}],[]}, or have {module, function, listofargs, ...}. should check

there no types module or function name function arity match number of arguments in phone call (list in error message) function exported

all local calls (like loop(someargs), without module specified) not compile if function not defined. , can local phone call dynamically (funtionname(someargs) 1 time again without module name).

edit after comment need of local calls.

you utilize lambda this. there spawn/1 funciton, takes lambda (or fun if like), can phone call spawn( fun local_functino/0).. issue fact fun can not take arguments, there way around it, utilize of closures.

spawn(fun () -> gen_server_loop(module, module:init()) end).

and gen_serve_loop stays local call.

erlang gen-server