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