The type of kinds of terrain tiles.
The type of kinds of terrain tiles. See
Tile.hs for explanation
of the absence of a corresponding type
Tile that would hold
particular concrete tiles in the dungeon.
Filter a list of kinds, passing through only the incorrect ones, if any.
If tiles look the same on the map, the description should be the same, too. Otherwise, the player has to inspect manually all the tiles of that kind to see if any is special. This is a part of a stronger but less precise property that tiles that look the same can't be distinguished by player actions (but may behave differently wrt dungeon generation, AI preferences, etc.).