Erlang, Matching with list foreach -

i've been making chat application in erlang school project, i've run issue. i'm trying make program concurrent , in order start new thread each message channel sending. using lists:foreach, want make sure don't message person typed in channel.

request(state, {message, {userid,userpid}, token}) -> case catch lists:member({userid,userpid}, state#channel.users) of     false ->         {{error, user_not_joined}, state};     true ->          spawn( fun() ->         listofusers = state#channel.users,         userpids = lists:map(fun ({_, v}) -> v end, listofusers),         %spawn( fun() ->end)         lists:foreach(              fun(userpid) -> ok end,             fun(pid) ->                 spawn( fun() -> genserver:request(pid, {message_from_server, state#channel.name, userid, token}) end)              end, userpids) end),         {ok, state} end; 

what pretty want match userpid inside foreach. of warnings:

channel.erl:39: warning: variable 'userpid' unused channel.erl:39: warning: variable 'userpid' shadowed in 'fun'

line 3 fun(userpid) -> ok end,

cheers

the answer legoscia fine, i'd add list comprehension simpler use , simpler read lists:foreach. note list comprehension able ignore values based on clauses. consider following example:

-module(filter).  -export([do/0]).  do() ->     values = lists:seq(1,10),     ignorethisvalue = 5,     %% print values unequal ignorethisvalue     [io:format("value: ~b~n", [value]) ||      value <- values, value =/= ignorethisvalue],     ok. 

run in shell:

1> make:all([load]). recompile: filter up_to_date 2> filter:do().      value: 1 value: 2 value: 3 value: 4 value: 6 value: 7 value: 8 value: 9 value: 10 

a side note on code: why spawn thread per process? assume using behaviour gen_server (correct me if wrong). if so, should consider using cast function send message. not check result of genserver:request/2, might viable option saves lot of processes.