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I have created some custom modules I need to create documentation for all my custom module So any help?
You can use edoc - http://erlang.org/doc/apps/edoc/chapter.html. Eg:
test_edoc.erl
-module(test_edoc).
-export([run/1]).
%% -------------------------------------------------------------------
%% #doc
%% Some description
%% #end
%% -------------------------------------------------------------------
-spec run(N :: integer()) -> Result :: integer() | error.
run(N) when is_integer(N) -> N + 1;
run(_) -> error.
Then in Erlang shell:
1> edoc:files(["test_edoc.erl"], [{dir, doc}]).
ok
Then in current folder where you run edoc:files/2 should be generated the doc folder, so, go to the doc folder and open in browser test_edoc.html
trying to use function string:find/2but every time getting the error
CRASH REPORT Process <0.779.0> with 0 neighbours exited with reason: {{undef,[{string,find,[[<<208,162,51,32,208,190,208,177,209,137,46,44,32,84,51,32,116,111,116,97,108,44>>],[<<208,186,209,128,208,190,208,178>>]],[]},{proxy_layer_cli_handle_req,do_execute_keysearch,4,[{file,\"/opt/proxy_layer/_build/test/lib/proxy_layer/src/proxy_layer_cli_handle_req.erl\"},{line,222}]},{proxy_layer_cli_handle_req,keysearch,3,[{file,\"/opt/proxy_layer/_build/test/lib/proxy_layer/src/proxy_layer_cli_handle_req.erl\"},{line,...}]},...]},...}
when i use it in terminal - everything is okay
1> string:find(<<208,162,51,32,208,190,208,177,209,137,46,44,32,84,51,32,116,111,116,97,108,44>>,<<208,186,209,128,208,190,208,178>>).
1> nomatch
I'm using Erlang 20.1
here is the code which I use:
do_execute_keysearch([First|Rest], PriceList, Keyword, Acc) ->
Id = utils:get_value(<<"Id">>, First),
case utils:get_value(<<"Keywords">>, First) of
<<>> -> do_execute_keysearch(Rest, PriceList, Keyword, Acc);
undefined -> do_execute_keysearch(Rest, PriceList, Keyword, Acc);
Keys ->
case string:find(Keys, Keyword) of
nomatch ->
do_execute_keysearch(Rest, PriceList, Keyword, Acc);
_ ->
Price = find_price_by_service_id(PriceList, Id),
NewAcc = [lists:append(Price, First) | Acc],
do_execute_keysearch(Rest, PriceList, Keyword, NewAcc)
end
end;
UPDATE:
Issue fixed after changing Erlang version in docker container. (Changed to Erlang 20.1)
Don’t know why there are some modules undefined in Erlang 19
So the problem solved now
string:find/2 was added to Erlang in version 20 which is why you were getting an undef error in Erlang 19. The solution is to upgrade to Erlang 20 (which you've already done).
Look at the error more carefully. Or rather, try to reproduce it. Which of these looks more like your error?
1> catch lists:nonexist(<<1>>, <<2>>).
{'EXIT',{undef,[{lists,nonexist,[<<1>>,<<2>>],[]},
{erl_eval,do_apply,6,[{file,"erl_eval.erl"},{line,674}]},
{erl_eval,expr,5,[{file,"erl_eval.erl"},{line,431}]},
{shell,exprs,7,[{file,"shell.erl"},{line,687}]},
{shell,eval_exprs,7,[{file,"shell.erl"},{line,642}]},
{shell,eval_loop,3,[{file,"shell.erl"},{line,627}]}]}}
2> catch lists:nonexist([<<1>>], [<<2>>]).
{'EXIT',{undef,[{lists,nonexist,[[<<1>>],[<<2>>]],[]},
{erl_eval,do_apply,6,[{file,"erl_eval.erl"},{line,674}]},
{erl_eval,expr,5,[{file,"erl_eval.erl"},{line,431}]},
{shell,exprs,7,[{file,"shell.erl"},{line,687}]},
{shell,eval_exprs,7,[{file,"shell.erl"},{line,642}]},
{shell,eval_loop,3,[{file,"shell.erl"},{line,627}]}]}}
I'm trying to call a function (from an external module) in erlang. both beam files are located in the same directory.
-module(drop2).
-export([fall_velocity/1]).
fall_velocity(Distance) -> math:sqrt(2 * 9.8 * Distance).
Then I'm calling
-module(ask).
-export([term/0]).
term() ->
Input = io:read("Enter {x,distance} ? >>"),
Term = element(2,Input),
drop2:fall_velocity(Term).
it gives the following error.I tested individual modules for errors. it is compiling with out any errors or warning.
Eshell V5.10.2 (abort with ^G)
1> ask:term().
Enter {x,distance} ? >>{test,10}.
** exception error: an error occurred when evaluating an arithmetic expression
in function drop2:fall_velocity/1 (drop2.erl, line 3)
Not sure why it is throwing arithmetic expression error .
You could read the documentation to figure out that the result is {ok, Term}. You could try the io:read/1 function in the console, then you'd see following:
1> io:read("Enter > ").
Enter > {test, 42}.
{ok,{test,42}}
2>
That means that you need to deconstruct the result of io:read/1 differently, for example like this:
-module(ask).
-export([term/0]).
term() ->
{ok, {_, Distance}} = io:read("Enter {x, distance} > "),
drop2:fall_velocity(Distance).
I am trying to run a start script but I end up with the following error.
{"init terminating in do_boot",{{case_clause,{error,{not_started,ranch}}},[{egs,ensure_started,1,[{file,"src/egs.erl"},{line,84}]},{egs,start,0,[{file,"src/egs.erl"},{line,49}]},{init,start_it,1,[]},{init,start_em,1,[]}]}}
I can compile the entire folder with multiple dependencies and this is the only one with an error. I use 'make' to compile and it is supposed to be 'make run' to run but that isn't working. Is that why I am getting this error? Any ideas on how to fix it would be greatly appreciated.
The file where I get the error from is below.
-module(egs).
-export([start/0, stop/0, global/1, warp/4, warp/5]). %% API.
%% Player and account-related types.
-type gid() :: 0..16#ffffffff.
-type lid() :: 0..1023 | 16#ffff.
-type character_slot() :: 0..3.
-export_type([gid/0, lid/0, character_slot/0]).
%% Location related types.
-type uniid() :: 21 | 26..254 | 16#ffffffff.
-type questid() :: 0..16#ffffffff. %% #todo What's the real max?
-type zoneid() :: 0..16#ffff. %% #todo What's the real max?
-type mapid() :: 0..9999.
-type entryid() :: 0..16#ffff. %% #todo What's the real max?
-type area() :: {questid(), zoneid(), mapid()}. %% #todo Probably remove later.
-type position() :: {X::float(), Y::float(), Z::float(), Dir::float()}.
-export_type([uniid/0, questid/0, zoneid/0, mapid/0, entryid/0,
area/0, position/0]).
%% API.
-spec start() -> ok.
start() ->
ensure_started(crypto),
ensure_started(public_key),
ensure_started(ssl),
ensure_started(cowboy),
ensure_started(ranch),
application:start(egs).
-spec stop() -> ok.
stop() ->
Res = application:stop(egs),
ok = application:stop(cowboy),
ok = application:stop(ranch),
ok = application:stop(ssl),
ok = application:stop(public_key),
ok = application:stop(crypto),
Res.
%% #doc Send a global message.
-spec global(string()) -> ok.
global(Message) when length(Message) > 511 ->
io:format("global: message too long~n");
global(Message) ->
egs_users:broadcast_all({egs, notice, top, Message}).
%% #doc Warp all players to a new map.
-spec warp(questid(), zoneid(), mapid(), entryid()) -> ok.
warp(QuestID, ZoneID, MapID, EntryID) ->
egs_users:broadcast_all({egs, warp, QuestID, ZoneID, MapID, EntryID}).
%% #doc Warp one player to a new map.
-spec warp(gid(), questid(), zoneid(), mapid(), entryid()) -> ok.
warp(GID, QuestID, ZoneID, MapID, EntryID) ->
egs_users:broadcast({egs, warp, QuestID, ZoneID, MapID, EntryID}, [GID]).
%% Internal.
-spec ensure_started(module()) -> ok.
ensure_started(App) ->
case application:start(App) of
ok -> ok;
{error, {already_started, App}} -> ok
end.
The order of application startup is important. In particular, cowboy depends on ranch and crypto. Also, public_key depends on crypto and must be started before ssl. The correct start order is:
ok = application:start(crypto),
ok = application:start(public_key),
ok = application:start(ssl),
ok = application:start(ranch),
ok = application:start(cowboy),
ok = application:start(egs).
For applications built with Rebar, the startup dependencies are listed in [app]/src/[app].app.src. See the LYSE chapter.
The reason it didn't work out of the box is probably that EGS depends on Cowboy's master branch, which quite recently introduced Ranch as a dependency.
I have following module
-module(bhavcopy_downloader).
-export([download/2]).
download(From, SaveTo) ->
{ok, {{Status, _}, _, Body}} = lhttpc:request(From, "GET", [], infinity),
case Status of
200 -> file:write(SaveTo, Body),
true;
_ -> false
end.
And following tests for the above code
file_download_test_() ->
{foreach,
fun() ->
meck:new(lhttpc)
meck:new(file, [unstick])
end,
fun(_) ->
meck:unload(file),
meck:unload(lhttpc)
end,
{"saves the file at specified location",
fun() ->
meck:expect(lhttpc, request, 4, {ok, {{200, "OK"}, [], <<"response">>}}),
meck:expect(file, write_file, fun(Path, Data) ->
?assertEqual(Path, "~/Downloads/data-downloader/test.html"),
?assertEqual(Data, <<"response">>)
end),
?assertEqual(true, bhavcopy_downloader:download("http://google.com", "~/Downloads/data-downloader/test.html")),
?assert(meck:validate(file))
end}]
}.
When I run the tests I get following error (only part of the error pasted below for brevity). Looking at the error below, I am kind of feeling that file module is not being mocked (or the mock of file module being overridden when I set the other mock using meck:new(lhttpc). What could be going wrong here?
=ERROR REPORT==== 16-Feb-2013::20:17:24 ===
** Generic server file_meck terminating
** Last message in was {'EXIT',<0.110.0>,
{compile_forms,
{error,
[{[],
[{none,compile,
{crash,beam_asm,
{undef,
[{file,get_cwd,[],[]},
{filename,absname,1,
[{file,"filename.erl"},{line,67}]},
{compile,beam_asm,1,
[{file,"compile.erl"},{line,1245}]},
{compile,'-internal_comp/4-anonymous-1-',2,
[{file,"compile.erl"},{line,273}]},
{compile,fold_comp,3,
[{file,"compile.erl"},{line,291}]},
{compile,internal_comp,4,
[{file,"compile.erl"},{line,275}]},
{compile,'-do_compile/2-anonymous-0-',2,
[{file,"compile.erl"},{line,152}]}]}}}]}],
[{"src/lhttpc_types.hrl",
[{31,erl_lint,{new_builtin_type,{boolean,0}}},
{31,erl_lint,{renamed_type,bool,boolean}}]}]}}}
This is a catch 22 in Meck, caused by the fact that Meck uses the Erlang compiler, which in turns uses the file module. When Meck tries recompile the file module it needs the file module (through the compiler) and thus crashes.
As of this moment, Meck doesn't handle mocking the file module. Your best alternative is to wrap the file module calls in another module and mock this module instead.
(It is theoretically possible to fix this in Meck by using the internals of the compiler and the code server instead, for example erlang:load_module/2, however this is quite tricky and needs to be designed and tested well)