A grid with a fixes amount of columns and rows.

It will wrap the borders (apply ModBy), making every position valid.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> get ( -1, 0 )
--> grid |> get ( (dimensions |> .columns) - 1, 0 )

If instead you want to have hard border around your grid, use Grid.Bordered instead.

Create a grid

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


fill (always <| Just ()) dimensions |> emptyPositions
--> []

Create an empty grid

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


empty dimensions
--> fill (always Nothing ) dimensions

Insert a value at a position in a grid. Replaces value when there is a collision.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> insert (2,2) 42 |> get (2,2)
--> Just 42

Update the value of a grid for a specific position with a given function.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> update (2,2) (always <| Just 42)
--> grid |> insert (2,2) 42

Remove a vlaue from a grid. If the position is empty, no changes are made.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> insert (2,2) 42 |> get (2,2) --> Just 42
grid |> insert (2,2) 42 |> remove (2,2) |> get (2,2)
--> Nothing

Determine if a grid is empty.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> isEmpty --> True
grid |> insert (2,2) 42 |> isEmpty --> False

Determine if a position is empty.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> insert (2,2) 42 |> member (2,2)
--> True

Get the value associated with a position. If the position is empty, return Nothing.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> insert (2,2) 42 |> get (2,2)
--> Just 42

Determine the number of values in the grid.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> insert (2,2) 42 |> size
--> 1

Return the dimensions of the grid.

dim : { columns:Int , rows:Int }
dim =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dim


grid |> dimensions
--> dim

Get all non empty positions in a grid, sorted from lowest to highest.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> insert (2,2) 42 |> positions
--> [(2,2)]

Get all empty positions in a grid, sorted from lowest to highest.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid Int
grid =
    fill
        (always <| Just <| 42)
        dimensions


grid |> remove (2,2) |> emptyPositions
--> [(2,2)]

Get all of the values in a grid, in the order of their positions.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid a
grid =
    empty dimensions


grid |> insert (2,2) 42 |> values
--> [42]

Convert a grid into an association list of position-value pairs, sorted by the position.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid Int
grid =
    empty dimensions


grid |> insert (2,2) 42 |> toList
--> [( (2,2), 42 )]

Convert an association list into a grid.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid Int
grid =
    empty dimensions


[((2,2),42),((2,1),20)] |> fromList dimensions
--> grid |> insert (2,2) 42 |> insert (2,1) 20

Convert a grid into an associated dictionary

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid Int
grid =
    empty dimensions
        |> insert (2,2) 42


grid |> toDict |> fromDict dimensions |> get (2,2)
--> Just 42

Convert an dictionary to a grid

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid Int
grid =
    empty dimensions


grid |> toDict |> fromDict dimensions |> get (2,2)
--> Nothing

Apply a function to all positions in a grid.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


empty dimensions |> map (\_ _ -> Just 42)
--> fill (always <| Just 42) dimensions

Fold over all positions in a grid, row by row, from top down.

Fold over all positions in a grid, row by row, from bottum up.

Keep only the values that pass the given test.

dimensions : { columns:Int , rows:Int }
dimensions =
    { columns=42
    , rows=3
    }


grid : Grid Int
grid =
    empty dimensions
        |> insert (2,4) 2
        |> insert (2,3) 42


grid |> filter (\_ -> (==) 42) |> values
--> [42]

Partition a grid according to some test.

The first grid contains all values which passed the test, and the second contains the values that did not.

Find the first value that passes a given test.

Combine two grids. If there is a collision, preference is given to the first grid.

Keep a value when its position appears in the second grid. Preference is given to values in the first grid.

Keep a value when its position does not appear in the second grid.