Set and Remove Pawns

Now that the board is constructed, you will place pawns on the board, check whether a pawn exists at a particular tile coordinate, and remove a pawn from the board.

Start with the following scenario. Given a tile_coordinate, determine whether there is a pawn there, and, if there is, retrieve it. The idea is as follows:

• The board holds an array of creative_prop pawns.
• Iterate through the existing pawns and obtain each pawn location as a tile coordinate.
• If there is a pawn at the given tile coordinate, retrieve it.
• If there is not, the function fails.

Determine Tile Coordinate Equality

This requires that you have the ability to test whether two tile_coordinate's are equal. This is necessary because our custom tile coordinate data type is not a subtype of Verse's built-in comparable type. As a result, you need to manually define what it means for two tile coordinates to be equal. First, create a AreTileCoordinatesEqual function in the DataTypesmodule to determine this:

|  |  |
| --- | --- |
|  | using { /Verse.org/Simulation } |
|  |  |
|  | DataTypes<public> := module: |
|  |  |
|  | ... |
|  |  |
|  | UtilityFunctions<public> := module: |
|  |  |
|  | ... |
|  |  |
|  | AreTileCoordinatesEqual<public>(LeftTileCoordinate:tile_coordinate, RightTileCoordinate:tile_coordinate)<decides><transacts>:void = |
|  | LeftTileCoordinate.Left = RightTileCoordinate.Left |
|  | LeftTileCoordinate.Forward = RightTileCoordinate.Forward |