lab3

-module(lab2).
-compile([export_all]).

map_append(Key, Value, Map) -> Map#{Key => Value}.
map_update(Key, Value, Map) -> Map#{Key := Value}.

map_display(Map) -> maps:map(fun entry_display/2, Map).
entry_display(Key, Value) -> io:format("~p=>~p\n", [Key,Value]).

print_file_map(Filename) ->
  {ok, Binary} = file:read_file(Filename),
  Tokens = string:tokens(binary:bin_to_list(Binary), "\n "),
  TrimTokens = lists:map(fun string:trim/1, Tokens),
  Map = #{},
  mapFromList(TrimTokens, Map),
  map_display(Map).

mapFromList([Head | Tail], Map) ->
    Check = maps:is_key(Head, Map),
    if
      Check == true ->
        Value = maps:get(Head, Map),
        NewMap = map_update(Head, Value+1, Map);
      Check == false ->
        NewMap = map_append(Head, 1, Map)
    end,
    mapFromList(Tail, NewMap);

  mapFromList([], Map) -> map_display(Map).

% list:map na mape map_append(key, 0) gdy nie ma klucza, update value++ otherwise

% Map = #{a=>'1',b=>'2',c=>'3'}.
% zad1:map_display(Map),ok.

% file:read_file('ala').