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|
-module(location).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% TYPES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-type type() :: {non_neg_integer(), non_neg_integer()}.
-export_type([type/0]).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-export
(
[
decode/1,
encode/1
]
).
-export
(
[
apply_direction/2,
dist/2
]
).
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec validate ({integer(), integer()}) -> type().
validate ({X, Y}) ->
true = (X >= 0),
true = (Y >= 0),
{X, Y}.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-spec apply_direction (direction:enum(), type()) -> type().
apply_direction (left, {X, Y}) ->
validate({(X - 1), Y});
apply_direction (right, {X, Y}) ->
validate({(X + 1), Y});
apply_direction (up, {X, Y}) ->
validate({X, (Y - 1)});
apply_direction (down, {X, Y}) ->
validate({X, (Y + 1)}).
-spec dist(type(), type()) -> non_neg_integer().
dist ({OX, OY}, {DX, DY}) ->
(abs(DY - OY) + abs(DX - OX)).
-spec encode (type()) -> {list(any())}.
encode ({X, Y}) ->
{
[
{<<"x">>, X},
{<<"y">>, Y}
]
}.
-spec decode (map()) -> type().
decode (Map) ->
X = maps:get(<<"x">>, Map),
Y = maps:get(<<"y">>, Map),
true = (is_integer(X) and is_integer(Y)),
validate({X, Y}).
|
