Data.Puzzles.GridShape

Grid shapes.

Documentation

class Show (Cell a) => GridShape a where

The geometry of a grid.

Associated Types

type GridSize a :: *

type Cell a :: *

type Vertex a :: *

Methods

size :: a -> GridSize a

cells :: a -> [Cell a]

vertices :: a -> [Vertex a]

vertexNeighbours :: a -> Cell a -> [Cell a]

edgeNeighbours :: a -> Cell a -> [Cell a]

Instances

GridShape Square

data Square

A standard square grid, with cells and vertices indexed by pairs of integers in mathematical coordinates. The bottom-left corner is vertex (0, 0), the bottom-left cell is cell (0, 0).

Constructors

Square !Int !Int

Instances

Eq Square

Show Square

GridShape Square

type GridSize Square = (Int, Int)

type Cell Square = (Int, Int)

type Vertex Square = (Int, Int)

squareNeighbours :: [(Int, Int)] -> Square -> Cell Square -> [Cell Square]

data Dir

Edge direction in a square grid, vertical or horizontal.

Constructors

V

H

Instances

Eq Dir

Ord Dir

Show Dir

data Edge

An edge in a square grid, going up or right from the given cell centre.

Constructors

E (Cell Square) Dir

Instances

Eq Edge

Ord Edge

Show Edge

type Coord = Cell Square

type Size = GridSize Square

data Dir'

Oriented edge direction in a square grid.

Constructors

U

D

L

R

Instances

Eq Dir'

Ord Dir'

Show Dir'

data Edge' a

An oriented edge in a square grid. a should be Cell Square or Vertex Square.

Constructors

E' a Dir'

Instances

Eq a => Eq (Edge' a)

Ord a => Ord (Edge' a)

Show a => Show (Edge' a)

orientedEdge :: Cell Square -> Cell Square -> Edge' (Vertex Square)

The edge between two neighbouring cells, with the first cell on the left.

edges :: Foldable f => f (Cell Square) -> (Cell Square -> Bool) -> ([Edge' (Vertex Square)], [Edge' (Vertex Square)])

edges computes the outer and inner edges of a set of cells. The set is given via fold and membership predicate, the result is a pair (outer, inner) of lists of edges, where the outer edges are oriented such that the outside is to the left.