1	import Base
2	
3	# The interface between the game and its laws. LAWS.bend talks about the game
4	# only through these types and the accessors in game.bend.
5	
6	# A grid is a list of rows. A layout is a grid of Bool, True where a mine is.
7	def Grid(-A: Data) -> Data:
8	  List<&2, List<&2, A>>
9	
10	# A cell: column x, row y; Pos{0n, 0n} is the top-left cell.
11	type Pos is Data:
12	  Pos{x: Nat, y: Nat}
13	
14	# What the player sees in one cell. Flags are not here: they are the player's
15	# beliefs, not knowledge.
16	type Seen is Data:
17	  Hidden{}
18	  Shown{n: Nat}
19	  Boom{}
20	
21	# Everything the player knows: the board is w columns by h rows, it holds
22	# `mines` mines in total, and `rows` holds one Seen per cell, row by row.
23	type Knowledge is Data:
24	  Knowledge{w: Nat, h: Nat, mines: Nat, rows: Grid(Seen)}
25	
26	# What the player can do. The assist carries a random number, which picks
27	# the cell it opens when the player is stuck.
28	type Action is Data:
29	  Reveal{p: Pos}
30	  Chord{p: Pos}
31	  Flag{p: Pos}
32	  Assist{k: Nat}
33	
34	# Why a game was lost: the player revealed the mine at p, or pressed the assist
35	# while `safe` could have been revealed without guessing.
36	type Loss is Data:
37	  Exploded{p: Pos}
38	  AssistTooEarly{safe: Pos}
39	
40	type Status is Data:
41	  Playing{}
42	  Won{}
43	  Lost{why: Loss}
44	
45	# A board size and mine count, as in Windows XP's Game menu.
46	type Level is Data:
47	  Beginner{}
48	  Intermediate{}
49	  Expert{}
50	  Custom{w: Nat, h: Nat, mines: Nat}
51	
52	type Setup is Data:
53	  Setup{w: Nat, h: Nat, mines: Nat}
54	
55	# What one cell looks like on screen.
56	type Tile is Data:
57	  Covered{}
58	  Flagged{}
59	  Number{n: Nat}
60	  Blast{}
61	  Mine{}
62	  BadFlag{}
63	  Hint{}