Implement basic communications and messages.

Go/Decoders.elm

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+module Go.Decoders exposing (..)
+import Go.Types exposing (..)
+import Json.Decode as Decode
+import Json.Decode.Pipeline exposing (decode, required)
+
+pair : a -> b -> (a, b)
+pair a1 a2 = (a1, a2)
+
+decodeIndex : Decode.Decoder Index
+decodeIndex = decode pair
+    |> required "x" Decode.int
+    |> required "y" Decode.int
+
+decodeColor : Decode.Decoder Color
+decodeColor = 
+    let
+        tryDecode : String -> Decode.Decoder Color
+        tryDecode s = case s of
+            "White" -> Decode.succeed White
+            "Black" -> Decode.succeed Black
+            _ -> Decode.fail "Invalid color"
+    in
+        Decode.andThen tryDecode Decode.string 
+
+decodeCell : Decode.Decoder Cell
+decodeCell = decode pair
+    |> required "index" decodeIndex
+    |> required "color" decodeColor
+
+decodeUpdate : Decode.Decoder Update
+decodeUpdate = decode pair
+    |> required "turn" decodeColor
+    |> required "board" (Decode.list decodeCell)
+
+decodeUpdatestring : String -> Result String Update
+decodeUpdatestring = Decode.decodeString decodeUpdate