Re-order functions to reflect the order of the Python code

sudoku.erl

@@ -2,6 +2,52 @@
 -import(lists, [member/2, filter/2, map/2, flatmap/2, sort/1, all/2, sum/1]).
 -compile(export_all).
 
+cross(SeqA, SeqB) ->
+    %% Cross product of elements in SeqA and elements in SeqB.
+    [[X,Y] || X <- SeqA, Y <- SeqB].
+
+digits() ->
+    "123456789".
+rows() ->
+    "ABCDEFGHI".
+cols() ->
+    digits().
+
+values(Puzzle, Square) ->
+    {Dict, _} = Puzzle,
+    dict:fetch(Square, Dict).
+
+squares() ->
+    %% Returns a list of 81 square names, including "A1" etc.
+    cross(rows(), cols()).
+
+col_squares() ->
+    %% All the square names for each column.
+    [cross(rows(), [C]) || C <- cols()].
+row_squares() ->
+    %% All the square names for each row.
+    [cross([R], cols()) || R <- rows()].
+box_squares() ->
+    %% All the square names for each box.
+    [cross(Rows, Cols) || Rows <- ["ABC", "DEF", "GHI"],
+                          Cols <- ["123", "456", "789"]].
+
+unitlist() ->
+    %% A list of all units (columns, rows, boxes) in a grid.
+    col_squares() ++ row_squares() ++ box_squares().
+
+units(Square) ->
+    %% A list of units for a specific square
+    [S || S <- unitlist(), member(Square, S)].
+
+peers(Square) ->
+    %% A unique list of squares (excluding this one)
+    %% that are also part of the units for this square.
+    NonUniquePeers = shallow_flatten([S || S <- units(Square)]),
+    PeerSet = sets:from_list(NonUniquePeers),
+    PeersWithSelf = sets:to_list(PeerSet),
+    lists:delete(Square, PeersWithSelf).
+
 print_results(Filename, Seperator) ->
     {Time, Solutions} = timer:tc(sudoku, solve_file, [Filename, Seperator]),
     Solved = filter(fun(Puzzle) -> is_solved(Puzzle) end, Solutions),
@@ -183,52 +229,6 @@ empty_dict() ->
     Digits = digits(),
     dict:from_list([{Square, Digits} || Square <- squares()]).
 
-cross(SeqA, SeqB) ->
-    %% Cross product of elements in SeqA and elements in SeqB.
-    [[X,Y] || X <- SeqA, Y <- SeqB].
-
-digits() ->
-    "123456789".
-rows() ->
-    "ABCDEFGHI".
-cols() ->
-    digits().
-
-values(Puzzle, Square) ->
-    {Dict, _} = Puzzle,
-    dict:fetch(Square, Dict).
-
-squares() ->
-    %% Returns a list of 81 square names, including "A1" etc.
-    cross(rows(), cols()).
-
-col_squares() ->
-    %% All the square names for each column.
-    [cross(rows(), [C]) || C <- cols()].
-row_squares() ->
-    %% All the square names for each row.
-    [cross([R], cols()) || R <- rows()].
-box_squares() ->
-    %% All the square names for each box.
-    [cross(Rows, Cols) || Rows <- ["ABC", "DEF", "GHI"],
-                          Cols <- ["123", "456", "789"]].
-
-unitlist() ->
-    %% A list of all units (columns, rows, boxes) in a grid.
-    col_squares() ++ row_squares() ++ box_squares().
-
-units(Square) ->
-    %% A list of units for a specific square
-    [S || S <- unitlist(), member(Square, S)].
-
-peers(Square) ->
-    %% A unique list of squares (excluding this one)
-    %% that are also part of the units for this square.
-    NonUniquePeers = shallow_flatten([S || S <- units(Square)]),
-    PeerSet = sets:from_list(NonUniquePeers),
-    PeersWithSelf = sets:to_list(PeerSet),
-    lists:delete(Square, PeersWithSelf).
-
 shallow_flatten([]) -> [];
 shallow_flatten([H|T]) ->
     H ++ shallow_flatten(T).