content: {-|
  Copyright  :  (C) 2013-2016, University of Twente
                    2025     , QBayLogic B.V.
  License    :  BSD2 (see the file LICENSE)
  Maintainer :  Christiaan Baaij <christiaan.baaij@gmail.com>
  -}
  
  {-# LANGUAGE Trustworthy #-}
  
  {-# OPTIONS_GHC -fplugin GHC.TypeLits.Extra.Solver -fplugin GHC.TypeLits.KnownNat.Solver #-}
  {-# OPTIONS_GHC -fplugin GHC.TypeLits.Normalise  #-}
  {-# OPTIONS_GHC -fno-warn-unused-imports #-}
  {-# OPTIONS_HADDOCK show-extensions #-}
  
  module Clash.Sized.Index
    (Index, bv2i, fromSNat)
  where
  
  import GHC.TypeLits (KnownNat, type (^))
  import GHC.TypeLits.Extra (CLog) -- documentation only
  
  import Clash.Sized.Internal.BitVector (BitVector)
  import Clash.Sized.Internal.Index
  
  -- | An alternative implementation of 'Clash.Class.BitPack.unpack' for the
  -- 'Index' data type; for when you know the size of the 'BitVector' and want
  -- to determine the size of the 'Index'.
  --
  -- That is, the type of 'Clash.Class.BitPack.unpack' is:
  --
  -- @
  -- __unpack__ :: 'BitVector' ('CLog' 2 n) -> 'Index' n
  -- @
  --
  -- And is useful when you know the size of the 'Index', and want to get a value
  -- from a 'BitVector' that is large enough (@CLog 2 n@) enough to hold an
  -- 'Index'. Note that 'Clash.Class.BitPack.unpack' can fail at /run-time/ when
  -- the value inside the 'BitVector' is higher than 'n-1'.
  --
  -- 'bv2i' on the other hand will /never/ fail at run-time, because the
  -- 'BitVector' argument determines the size.
  bv2i :: KnownNat n => BitVector n -> Index (2^n)
  bv2i = unpack#
  