1 files changed, 40 insertions, 3 deletions

diff --git a/src/battlemap/movement.erl b/src/battlemap/movement.erl
index 513d032..9eb45db 100644
--- a/src/battlemap/movement.erl
+++ b/src/battlemap/movement.erl
@@ -7,7 +7,6 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% EXPORTS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-
 -export
 (
    [
@@ -19,6 +18,13 @@
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% LOCAL FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec location_after_step
+   (
+      binary(),
+      integer(),
+      integer()
+   )
+   -> {integer(), integer()}.
 location_after_step (Step, X, Y) ->
    case Step of
       <<"L">> -> {(X - 1), Y};
@@ -27,10 +33,17 @@ location_after_step (Step, X, Y) ->
       <<"D">> -> {X, (Y + 1)}
    end.
 
+-spec location_to_array_index
+   (
+      non_neg_integer(),
+      integer(),
+      integer()
+   )
+   -> ('error' | non_neg_integer()).
 location_to_array_index (ArrayWidth, X, Y) ->
    if
-      (X < 0) -> -1;
-      (Y < 0) -> -1;
+      (X < 0) -> error;
+      (Y < 0) -> error;
       (X >= ArrayWidth) -> error;
       true -> ((Y * ArrayWidth) + X)
    end.
@@ -38,6 +51,16 @@ location_to_array_index (ArrayWidth, X, Y) ->
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %% EXPORTED FUNCTIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+-spec cross
+   (
+      battlemap:struct(),
+      array:array(non_neg_integer(), non_neg_integer()),
+      list(binary()),
+      non_neg_integer(),
+      non_neg_integer(),
+      non_neg_integer()
+   )
+   -> {{non_neg_integer(), non_neg_integer()}, non_neg_integer()}.
 cross (_Battlemap, _ForbiddenLocations, [], Cost, X, Y) ->
    {{X, Y}, Cost};
 cross (Battlemap, ForbiddenLocations, [Step|NextSteps], Cost, X, Y) ->
@@ -63,8 +86,22 @@ cross (Battlemap, ForbiddenLocations, [Step|NextSteps], Cost, X, Y) ->
 
    cross(Battlemap, ForbiddenLocations, NextSteps, NextCost, NextX, NextY).
 
+-spec cross
+   (
+      battlemap:struct(),
+      array:array(non_neg_integer(), non_neg_integer()),
+      list(binary()),
+      {non_neg_integer(), non_neg_integer()}
+   )
+   -> {{non_neg_integer(), non_neg_integer()}, non_neg_integer()}.
 cross (Battlemap, ForbiddenLocations, Path, {X, Y}) ->
    cross(Battlemap, ForbiddenLocations, Path, 0, X, Y).
 
+-spec steps_between
+   (
+      {non_neg_integer(), non_neg_integer()},
+      {non_neg_integer(), non_neg_integer()}
+   )
+   -> non_neg_integer().
 steps_between ({OX, OY}, {DX, DY}) ->
    (abs(DY - OY) + abs(DX - OX)).