Word.hs

module HaskellWorks.Data.RankSelect.Internal.Word
  ( toBools
  , toBoolsDiff
  , partialToBoolsDiff
  ) where

import Data.Word
import HaskellWorks.Data.Bits.BitWise
import HaskellWorks.Data.Positioning

toBools :: Word64 -> [Bool]
toBools w = toBoolsDiff w []

partialToBoolsDiff :: Count -> Word64 -> [Bool] -> [Bool]
partialToBoolsDiff n w | n > 0 = partialToBoolsDiff (n - 1) w . ((w .?. fromIntegral (n - 1)):)
partialToBoolsDiff 0 _ = id
partialToBoolsDiff _ _ = error "Invalid size"

toBoolsDiff :: Word64 -> [Bool] -> [Bool]
toBoolsDiff w =
  go 0x00 . go 0x01 . go 0x02 . go 0x03 . go 0x04 . go 0x05 . go 0x06 . go 0x07 .
  go 0x08 . go 0x09 . go 0x0a . go 0x0b . go 0x0c . go 0x0d . go 0x0e . go 0x0f .
  go 0x10 . go 0x11 . go 0x12 . go 0x13 . go 0x14 . go 0x15 . go 0x16 . go 0x17 .
  go 0x18 . go 0x19 . go 0x1a . go 0x1b . go 0x1c . go 0x1d . go 0x1e . go 0x1f .
  go 0x20 . go 0x21 . go 0x22 . go 0x23 . go 0x24 . go 0x25 . go 0x26 . go 0x27 .
  go 0x28 . go 0x29 . go 0x2a . go 0x2b . go 0x2c . go 0x2d . go 0x2e . go 0x2f .
  go 0x30 . go 0x31 . go 0x32 . go 0x33 . go 0x34 . go 0x35 . go 0x36 . go 0x37 .
  go 0x38 . go 0x39 . go 0x3a . go 0x3b . go 0x3c . go 0x3d . go 0x3e . go 0x3f
  where go :: Position -> [Bool] -> [Bool]
        go p = ((w .?. p):)