Drawing Warehouse

The Wonderful World of Warehouse

Warehouse has a lot of data types in it. The aim of this exercise is to get you comfortable with the world of warehouse and especially the interactionOf data type.

Step 1

Draw a picture of the warehouse. Label all the data types that you can see, including Tile, Coord, Direction and Picture.

Step 2

Let’s try and visualise interactionOf, which has the type signature:

interactionOf :: world ->
                (Double -> world -> world) ->
                (Event -> world -> world) ->
                (world -> Picture) ->
                IO ()

Putting interactionOf in action, we have

main = interactionOf initialCoord handleTime handleEvent drawState

handleTime :: Double -> Coord -> Coord
handleTime _ c = c

handleEvent :: Event -> Coord -> Coord
handleEvent e c = adjacentCoord U c

drawState :: Coord -> Picture
drawState c = atCoord c pictureOfMaze

Draw what handleTime, handleEvent and drawState does to the Warehouse in the context of the function main.

Step 3

Invent your own handleTime and handleEvent function! Don’t write it out in formal Haskell, but just talk in your group about a time based action and an event based action you could operate on the Warehouse. Draw it on your diagram!

Step 4

Talk about these topics in your group, and write down any ideas you have:

• Why does handleTime have the data type (Double -> world -> world)? Could it be anything else?
• Why does handleEvent have the data type Event -> Coord -> Coord? Could it be anything else?