Generate coords function from existing qwerty keyboard

Per my take-home assignment's reviewer's comments, with which for the record I
agree, I should generate the character->coordinate table from my existing qwerty
keyboard definition.

The best part is: by doing this I found a bug: Notice how the original '0'
character was mapped to the Coordinate (0,0)... thus every subsequent digit
key (i.e. the first row) is off-by-one.
This commit is contained in:
William Carroll 2020-08-12 09:46:36 +01:00
parent 4ff1ea291c
commit 17e1764ef8

View file

@ -5,6 +5,7 @@
module Keyboard where
--------------------------------------------------------------------------------
import Utils
import Data.Coerce
import Data.Hashable (Hashable)
import GHC.Generics (Generic)
@ -32,50 +33,13 @@ instance Hashable Coord
-- | List of characters to their QWERTY coordinatees.
coords :: [(Char, Coord)]
coords = [ ('0', Coord { row = 0, col = 0 })
, ('1', Coord { row = 0, col = 1 })
, ('2', Coord { row = 0, col = 2 })
, ('3', Coord { row = 0, col = 3 })
, ('4', Coord { row = 0, col = 4 })
, ('5', Coord { row = 0, col = 5 })
, ('6', Coord { row = 0, col = 6 })
, ('7', Coord { row = 0, col = 7 })
, ('8', Coord { row = 0, col = 8 })
, ('9', Coord { row = 0, col = 9 })
-- second row
, ('Q', Coord { row = 1, col = 0 })
, ('W', Coord { row = 1, col = 1 })
, ('E', Coord { row = 1, col = 2 })
, ('R', Coord { row = 1, col = 3 })
, ('T', Coord { row = 1, col = 4 })
, ('Y', Coord { row = 1, col = 5 })
, ('U', Coord { row = 1, col = 6 })
, ('I', Coord { row = 1, col = 7 })
, ('O', Coord { row = 1, col = 8 })
, ('P', Coord { row = 1, col = 9 })
-- third row
, ('A', Coord { row = 2, col = 0 })
, ('S', Coord { row = 2, col = 1 })
, ('D', Coord { row = 2, col = 2 })
, ('F', Coord { row = 2, col = 3 })
, ('G', Coord { row = 2, col = 4 })
, ('H', Coord { row = 2, col = 5 })
, ('J', Coord { row = 2, col = 6 })
, ('K', Coord { row = 2, col = 7 })
, ('L', Coord { row = 2, col = 8 })
, (';', Coord { row = 2, col = 9 })
-- fourth row
, ('Z', Coord { row = 3, col = 0 })
, ('X', Coord { row = 3, col = 1 })
, ('C', Coord { row = 3, col = 2 })
, ('V', Coord { row = 3, col = 3 })
, ('B', Coord { row = 3, col = 4 })
, ('N', Coord { row = 3, col = 5 })
, ('M', Coord { row = 3, col = 6 })
, (',', Coord { row = 3, col = 7 })
, ('.', Coord { row = 3, col = 8 })
, ('/', Coord { row = 3, col = 9 })
]
coords =
qwerty
|> coerce
|> fmap (zip [0..])
|> zip [0..]
|> fmap (\(row, xs) -> xs |> fmap (\(col, char) -> (char, Coord row col)))
|> mconcat
-- | Mapping of characters to their coordinates on a QWERTY keyboard with the
-- top-left corner as 0,0.