cloudi_core

%-*-Mode:erlang;coding:utf-8;tab-width:4;c-basic-offset:4;indent-tabs-mode:()-*-
% ex: set ft=erlang fenc=utf-8 sts=4 ts=4 sw=4 et:
%%%
%%%------------------------------------------------------------------------
%%% @doc
%%% ==Proplists Extensions Module==
%%% @end
%%%
%%% BSD LICENSE
%%% 
%%% Copyright (c) 2009-2013, Michael Truog <mjtruog at gmail dot com>
%%% All rights reserved.
%%% 
%%% Redistribution and use in source and binary forms, with or without
%%% modification, are permitted provided that the following conditions are met:
%%% 
%%%     * Redistributions of source code must retain the above copyright
%%%       notice, this list of conditions and the following disclaimer.
%%%     * Redistributions in binary form must reproduce the above copyright
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%%%       the documentation and/or other materials provided with the
%%%       distribution.
%%%     * All advertising materials mentioning features or use of this
%%%       software must display the following acknowledgment:
%%%         This product includes software developed by Michael Truog
%%%     * The name of the author may not be used to endorse or promote
%%%       products derived from this software without specific prior
%%%       written permission
%%% 
%%% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
%%% CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
%%% INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
%%% OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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%%%
%%% @author Michael Truog <mjtruog [at] gmail (dot) com>
%%% @copyright 2009-2013 Michael Truog
%%% @version 1.2.3 {@date} {@time}
%%%------------------------------------------------------------------------

-module(cloudi_proplists).
-author('mjtruog [at] gmail (dot) com').

-export([delete_all/2,
         partition/2,
         take_values/2]).

%%%------------------------------------------------------------------------
%%% External interface functions
%%%------------------------------------------------------------------------

-type tuplelist() :: list({atom(), any()}).

%%-------------------------------------------------------------------------
%% @doc
%% ===Delete all the instances of the keys provided.===
%% @end
%%-------------------------------------------------------------------------

-spec delete_all(Keys :: list(atom()),
                 List :: tuplelist()) -> tuplelist().

delete_all([], List) ->
    List;

delete_all([Key | Keys], List)
    when is_atom(Key), is_list(List) ->
    delete_all(Keys, proplists:delete(Key, List)).

%%-------------------------------------------------------------------------
%% @doc
%% ===Partition the proplist based on a key.===
%% @end
%%-------------------------------------------------------------------------

-spec partition(Key :: atom(),
                List :: tuplelist()) -> {tuplelist(), tuplelist()}.

partition(Key, List)
    when is_atom(Key), is_list(List) ->
    lists:partition(fun({K, _}) -> K == Key end, List).

%%-------------------------------------------------------------------------
%% @doc
%% ===Remove many keys from the proplist.===
%% The defaults are provided as a proplist
%% @end
%%-------------------------------------------------------------------------

-spec take_values(DefaultList :: tuplelist(),
                  List :: tuplelist()) -> list().

take_values(DefaultList, List)
    when is_list(DefaultList), is_list(List) ->
    take_values([], DefaultList, List).

take_values(Result, [], List)
    when is_list(Result), is_list(List) ->
    lists:reverse(Result) ++ List;

take_values(Result, [{Key, Default} | DefaultList], List)
    when is_list(Result), is_atom(Key), is_list(List) ->
    case lists:keytake(Key, 1, List) of
        false ->
            take_values([Default | Result], DefaultList, List);
        {value, {Key, Value}, RemainingList} ->
            take_values([Value | Result], DefaultList, RemainingList)
    end.