%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1996-2009. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(orddict).
%% Standard interface.
-export([new/0,is_key/2,to_list/1,from_list/1,size/1]).
-export([fetch/2,find/2,fetch_keys/1,erase/2]).
-export([store/3,append/3,append_list/3,update/3,update/4,update_counter/3]).
-export([fold/3,map/2,filter/2,merge/3]).
%%---------------------------------------------------------------------------
-type orddict() :: [{term(), term()}].
%%---------------------------------------------------------------------------
-spec new() -> orddict().
new() -> [].
-spec is_key(Key::term(), Dictionary::orddict()) -> boolean().
is_key(Key, [{K,_}|_]) when Key < K -> false;
is_key(Key, [{K,_}|Dict]) when Key > K -> is_key(Key, Dict);
is_key(_Key, [{_K,_Val}|_]) -> true; %Key == K
is_key(_, []) -> false.
-spec to_list(orddict()) -> [{term(), term()}].
to_list(Dict) -> Dict.
-spec from_list([{term(), term()}]) -> orddict().
from_list(Pairs) ->
lists:foldl(fun ({K,V}, D) -> store(K, V, D) end, [], Pairs).
-spec size(orddict()) -> non_neg_integer().
size(D) -> length(D).
-spec fetch(Key::term(), Dictionary::orddict()) -> term().
fetch(Key, [{K,_}|D]) when Key > K -> fetch(Key, D);
fetch(Key, [{K,Value}|_]) when Key == K -> Value.
-spec find(Key::term(), Dictionary::orddict()) -> {'ok', term()} | 'error'.
find(Key, [{K,_}|_]) when Key < K -> error;
find(Key, [{K,_}|D]) when Key > K -> find(Key, D);
find(_Key, [{_K,Value}|_]) -> {ok,Value}; %Key == K
find(_, []) -> error.
-spec fetch_keys(Dictionary::orddict()) -> [term()].
fetch_keys([{Key,_}|Dict]) ->
[Key|fetch_keys(Dict)];
fetch_keys([]) -> [].
-spec erase(Key::term(), Dictionary::orddict()) -> orddict().
erase(Key, [{K,_}=E|Dict]) when Key < K -> [E|Dict];
erase(Key, [{K,_}=E|Dict]) when Key > K ->
[E|erase(Key, Dict)];
erase(_Key, [{_K,_Val}|Dict]) -> Dict; %Key == K
erase(_, []) -> [].
-spec store(Key::term(), Value::term(), Dictionary::orddict()) -> orddict().
store(Key, New, [{K,_}=E|Dict]) when Key < K ->
[{Key,New},E|Dict];
store(Key, New, [{K,_}=E|Dict]) when Key > K ->
[E|store(Key, New, Dict)];
store(Key, New, [{_K,_Old}|Dict]) -> %Key == K
[{Key,New}|Dict];
store(Key, New, []) -> [{Key,New}].
-spec append(Key::term(), Value::term(), Dictionary::orddict()) -> orddict().
append(Key, New, [{K,_}=E|Dict]) when Key < K ->
[{Key,[New]},E|Dict];
append(Key, New, [{K,_}=E|Dict]) when Key > K ->
[E|append(Key, New, Dict)];
append(Key, New, [{_K,Old}|Dict]) -> %Key == K
[{Key,Old ++ [New]}|Dict];
append(Key, New, []) -> [{Key,[New]}].
-spec append_list(Key::term(), ValueList::[term()], orddict()) -> orddict().
append_list(Key, NewList, [{K,_}=E|Dict]) when Key < K ->
[{Key,NewList},E|Dict];
append_list(Key, NewList, [{K,_}=E|Dict]) when Key > K ->
[E|append_list(Key, NewList, Dict)];
append_list(Key, NewList, [{_K,Old}|Dict]) -> %Key == K
[{Key,Old ++ NewList}|Dict];
append_list(Key, NewList, []) ->
[{Key,NewList}].
-spec update(Key::term(), Fun::fun((term()) -> term()), orddict()) -> orddict().
update(Key, Fun, [{K,_}=E|Dict]) when Key > K ->
[E|update(Key, Fun, Dict)];
update(Key, Fun, [{K,Val}|Dict]) when Key == K ->
[{Key,Fun(Val)}|Dict].
-spec update(term(), fun((term()) -> term()), term(), orddict()) -> orddict().
update(Key, _, Init, [{K,_}=E|Dict]) when Key < K ->
[{Key,Init},E|Dict];
update(Key, Fun, Init, [{K,_}=E|Dict]) when Key > K ->
[E|update(Key, Fun, Init, Dict)];
update(Key, Fun, _Init, [{_K,Val}|Dict]) -> %Key == K
[{Key,Fun(Val)}|Dict];
update(Key, _, Init, []) -> [{Key,Init}].
-spec update_counter(Key::term(), Incr::number(), orddict()) -> orddict().
update_counter(Key, Incr, [{K,_}=E|Dict]) when Key < K ->
[{Key,Incr},E|Dict];
update_counter(Key, Incr, [{K,_}=E|Dict]) when Key > K ->
[E|update_counter(Key, Incr, Dict)];
update_counter(Key, Incr, [{_K,Val}|Dict]) -> %Key == K
[{Key,Val+Incr}|Dict];
update_counter(Key, Incr, []) -> [{Key,Incr}].
-spec fold(fun((term(),term(),term()) -> term()), term(), orddict()) -> term().
fold(F, Acc, [{Key,Val}|D]) ->
fold(F, F(Key, Val, Acc), D);
fold(F, Acc, []) when is_function(F, 3) -> Acc.
-spec map(fun((term(), term()) -> term()), orddict()) -> orddict().
map(F, [{Key,Val}|D]) ->
[{Key,F(Key, Val)}|map(F, D)];
map(F, []) when is_function(F, 2) -> [].
-spec filter(fun((term(), term()) -> boolean()), orddict()) -> orddict().
filter(F, [{Key,Val}=E|D]) ->
case F(Key, Val) of
true -> [E|filter(F, D)];
false -> filter(F, D)
end;
filter(F, []) when is_function(F, 2) -> [].
-spec merge(fun((term(), term(), term()) -> term()), orddict(), orddict()) ->
orddict().
merge(F, [{K1,_}=E1|D1], [{K2,_}=E2|D2]) when K1 < K2 ->
[E1|merge(F, D1, [E2|D2])];
merge(F, [{K1,_}=E1|D1], [{K2,_}=E2|D2]) when K1 > K2 ->
[E2|merge(F, [E1|D1], D2)];
merge(F, [{K1,V1}|D1], [{_K2,V2}|D2]) -> %K1 == K2
[{K1,F(K1, V1, V2)}|merge(F, D1, D2)];
merge(F, [], D2) when is_function(F, 3) -> D2;
merge(F, D1, []) when is_function(F, 3) -> D1.
