1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 | import Data.List (sort, nub) import Math.Geometry.Grid (Grid, neighbours, indices) ------------------------------------------------------------------------------ -- | A list of all edges in a Grid where an edge would represent the -- connection of two tiles, for example ((0,0),(0,1)). The list is sorted and -- duplicate edges are removed. -- edges :: (Grid g s x, Ord x) => g -> [(x,x)] edges grid = sort . nub . concat $ zipOrd ics neighbourList where ics = indices grid neighbourList = map (flip neighbours grid) ics zipOrd = zipWith (\i is -> zipWith orderPairs (repeat i) is) orderPairs a b | a < b = (a,b) | otherwise = (b,a) |

13:25: Warning: Use section

Found:

(flip neighbours grid)

Why not:

(`neighbours` grid)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | import Data.List (sort, nub) import Math.Geometry.Grid (Grid, neighbours, indices) ------------------------------------------------------------------------------ -- | A list of all edges in a Grid where an edge represents the connection of -- two adjacent tiles. The list is sorted and duplicate edges are removed. -- edges :: (Grid g s x, Ord x) => g -> [(x,x)] edges grid = sort . nub . concat $ zipOrd ics neighbourList where ics = indices grid neighbourList = map (`neighbours` grid) ics zipOrd = zipWith (\i is -> zipWith orderPairs (repeat i) is) orderPairs a b | a < b = (a,b) | otherwise = (b,a) |

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | import Data.List (sort, nub) import Math.Geometry.Grid (Grid, neighbours, indices) ------------------------------------------------------------------------------ -- | A list of all edges in a Grid where an edge represents the connection of -- two adjacent tiles. The list is sorted and duplicate edges are removed. -- edges :: (Grid g s x, Ord x) => g -> [(x,x)] edges grid = concat $ zipWith connect ics neighbourList where ics = indices grid neighbourList = map (`neighbours` grid) ics connect :: x -> [x] -> [(x,x)] connect _ [] = [] connect a (b:bs) | a < b = (a, b) : connect a bs | otherwise = connect a bs |

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 | import Data.List (sort, nub) import Math.Geometry.Grid (Grid, neighbours, indices) ------------------------------------------------------------------------------ -- | A list of all edges in a Grid where an edge represents the connection of -- two adjacent tiles. The list is sorted and duplicate edges are removed. -- edges :: (Grid g s x, Ord x) => g -> [(x,x)] edges grid = concat $ zipWith connect ics neighbourList where ics = indices grid neighbourList = map (`neighbours` grid) ics connect :: (Ord x) => x -> [x] -> [(x,x)] connect _ [] = [] connect a (b:bs) | a < b = (a, b) : connect a bs | otherwise = connect a bs |