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add search function for lists to ec_lists

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Signed-off-by: Jordan Wilberding <jwilberding@gmail.com>
This commit is contained in:
Eric Merritt 2011-09-26 11:47:15 -05:00 • committed by Jordan Wilberding
parent eecbb26a2d
commit 284ada2bd9
1 changed files with 82 additions and 9 deletions
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91
src/ec_lists.erl
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@ -9,12 +9,31 @@
%% API
-export([find/2,
fetch/2]).
fetch/2,
search/2]).
%%%===================================================================
%%% API
%%%===================================================================
%% @doc Search each value in the list with the specified
%% function. When the function returns a value of {ok, term()} the
%% search function stops and returns a tuple of {ok, term(), term()},
%% where the second value is the term returned from the function and
%% the third value is the element passed to the function. The purpose
%% of this is to allow a list to be searched where some internal state
%% is important while the input element is not.
-spec search(fun(), list()) -> {ok, Result::term(), Element::term()}.
search(Fun, [H|T]) ->
case Fun(H) of
{ok, Value} ->
{ok, Value, H};
not_found ->
search(Fun, T)
end;
search(_, []) ->
not_found.
%% @doc Find a value in the list with the specified function. If the
%% function returns the atom true, the value is returned as {ok,
%% term()} and processing is aborted, if the function returns false,
@ -160,13 +179,67 @@ fetch3_test() ->
?assertMatch({"one", 1}, Result),
?assertThrow(not_found,
fetch(fun([fo, bar, baz]) ->
true;
({"onehundred", 100}) ->
true;
(_) ->
false
end,
TestData)).
fetch(fun([fo, bar, baz]) ->
true;
({"onehundred", 100}) ->
true;
(_) ->
false
end,
TestData)).
search1_test() ->
TestData = [1, 2, 3, 4, 5, 6],
Result = search(fun(5) ->
{ok, 5};
(_) ->
not_found
end,
TestData),
?assertMatch({ok, 5, 5}, Result),
Result2 = search(fun(37) ->
{ok, 37};
(_) ->
not_found
end,
TestData),
?assertMatch(not_found, Result2).
search2_test() ->
TestData = [1, 2, 3, 4, 5, 6],
Result = search(fun(1) ->
{ok, 10};
(_) ->
not_found
end,
TestData),
?assertMatch({ok, 10, 1}, Result),
Result2 = search(fun(6) ->
{ok, 37};
(_) ->
not_found
end,
TestData),
?assertMatch({ok, 37, 6}, Result2).
search3_test() ->
TestData = [1, 2, 3, 4, 5, 6],
Result = search(fun(10) ->
{ok, 10};
(_) ->
not_found
end,
TestData),
?assertMatch(not_found, Result),
Result2 = search(fun(-1) ->
{ok, 37};
(_) ->
not_found
end,
TestData),
?assertMatch(not_found, Result2).
-endif.