33 lines
1.1 KiB
Elm
33 lines
1.1 KiB
Elm
module Go.Game exposing (verify)
|
|
import Go.Types exposing (..)
|
|
import Go.Util exposing (lookup)
|
|
|
|
-- Make sure it's our turn to play.
|
|
verifyTurn : Model -> Cell -> Maybe Cell
|
|
verifyTurn model c = if
|
|
(Just model.sessionColor) == model.currentColor then
|
|
Just c
|
|
else
|
|
Nothing
|
|
|
|
-- Make sure there's not already a piece where we're going.
|
|
verifyClear : Model -> Cell -> Maybe Cell
|
|
verifyClear model (indx, c) = case lookup indx model.board of
|
|
Just _ -> Nothing
|
|
Nothing -> Just (indx, c)
|
|
|
|
-- Make sure cell is in range of the board.
|
|
verifyBounds : Model -> Cell -> Maybe Cell
|
|
verifyBounds model ((x, y), c) = if x >= 0 && x < model.sessionSize && y >= 0 && y < model.sessionSize
|
|
then Just ((x, y), c)
|
|
else Nothing
|
|
|
|
-- Verify a cell placemenet using a list of verification functions.
|
|
verifyAll : Cell -> List (Model -> Cell -> Maybe Cell) -> Model -> Maybe Cell
|
|
verifyAll cell funcs model = List.foldl (\a b -> Maybe.andThen (a model) b) (Just cell) funcs
|
|
|
|
-- Make sure that a move to the given cell can be made.
|
|
verify : Cell -> Model -> Maybe Cell
|
|
verify cell model = verifyAll cell [verifyBounds, verifyTurn, verifyClear] model
|
|
|