stellar-veritas/bundled/Basement/From.hs

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2026-01-25 02:27:22 +01:00
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE DeriveDataTypeable #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE RebindableSyntax #-}
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE FlexibleInstances #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE ConstraintKinds #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE MagicHash #-}
{-# LANGUAGE UndecidableInstances #-}
{-# LANGUAGE TypeOperators #-}
-- |
-- Module : Basement.From
-- License : BSD-style
-- Maintainer : Haskell Foundation
--
-- Flexible Type convertion
--
-- From is multi parameter type class that allow converting
-- from a to b.
--
-- Only type that are valid to convert to another type
-- should be From instance; otherwise TryFrom should be used.
--
-- Into (resp TryInto) allows the contrary instances to be able
-- to specify the destination type before the source. This is
-- practical with TypeApplication
module Basement.From
( From(..)
, Into
, TryFrom(..)
, TryInto
, into
, tryInto
) where
import Basement.Compat.Base
-- basic instances
import GHC.Types
import GHC.Prim hiding (word64ToWord#)
import qualified GHC.Prim
import GHC.Int
import GHC.Word
import Basement.Numerical.Number
import Basement.Numerical.Conversion
import qualified Basement.Block as Block
import qualified Basement.BoxedArray as BoxArray
import Basement.Cast (cast)
import qualified Basement.UArray as UArray
import qualified Basement.String as String
import qualified Basement.Types.AsciiString as AsciiString
import Basement.Types.Word128 (Word128(..))
import Basement.Types.Word256 (Word256(..))
import qualified Basement.Types.Word128 as Word128
import qualified Basement.Types.Word256 as Word256
import Basement.These
import Basement.PrimType (PrimType, PrimSize)
import Basement.Types.OffsetSize
import Basement.Compat.Natural
import Basement.Compat.Primitive
import qualified Prelude (fromIntegral)
-- nat instances
#if __GLASGOW_HASKELL__ >= 800
import Basement.Nat
import qualified Basement.Sized.Block as BlockN
import Basement.Bounded
#endif
-- | Class of things that can be converted from a to b.
--
-- In a valid instance, the source should be always representable by the destination,
-- otherwise the instance should be using 'TryFrom'
class From a b where
from :: a -> b
type Into b a = From a b
-- | Same as from but reverse the type variable so that the destination type can be specified first
--
-- e.g. converting:
--
-- from @_ @Word (10 :: Int)
--
-- into @Word (10 :: Int)
--
into :: Into b a => a -> b
into = from
-- | Class of things that can mostly be converted from a to b, but with possible error cases.
class TryFrom a b where
tryFrom :: a -> Maybe b
type TryInto b a = TryFrom a b
-- | same as tryFrom but reversed
tryInto :: TryInto b a => a -> Maybe b
tryInto = tryFrom
instance From a a where
from = id
instance IsNatural n => From n Natural where
from = toNatural
instance IsIntegral n => From n Integer where
from = toInteger
instance From Int8 Int16 where
from (I8# i) = I16# (int8ToInt16# i)
instance From Int8 Int32 where
from (I8# i) = I32# (int8ToInt32# i)
instance From Int8 Int64 where
from (I8# i) = intToInt64 (I# (int8ToInt# i))
instance From Int8 Int where
from (I8# i) = I# (int8ToInt# i)
instance From Int16 Int32 where
from (I16# i) = I32# (int16ToInt32# i)
instance From Int16 Int64 where
from (I16# i) = intToInt64 (I# (int16ToInt# i))
instance From Int16 Int where
from (I16# i) = I# (int16ToInt# i)
instance From Int32 Int64 where
from (I32# i) = intToInt64 (I# (int32ToInt# i))
instance From Int32 Int where
from (I32# i) = I# (int32ToInt# i)
instance From Int Int64 where
from = intToInt64
instance From Word8 Word16 where
from (W8# i) = W16# (word8ToWord16# i)
instance From Word8 Word32 where
from (W8# i) = W32# (word8ToWord32# i)
instance From Word8 Word64 where
from (W8# i) = wordToWord64 (W# (word8ToWord# i))
instance From Word8 Word128 where
from (W8# i) = Word128 0 (wordToWord64 $ W# (word8ToWord# i))
instance From Word8 Word256 where
from (W8# i) = Word256 0 0 0 (wordToWord64 $ W# (word8ToWord# i))
instance From Word8 Word where
from (W8# i) = W# (word8ToWord# i)
instance From Word8 Int16 where
from (W8# w) = I16# (intToInt16# (word2Int# (word8ToWord# w)))
instance From Word8 Int32 where
from (W8# w) = I32# (intToInt32# (word2Int# (word8ToWord# w)))
instance From Word8 Int64 where
from (W8# w) = intToInt64 (I# (word2Int# (word8ToWord# w)))
instance From Word8 Int where
from (W8# w) = I# (word2Int# (word8ToWord# w))
instance From Word16 Word32 where
from (W16# i) = W32# (word16ToWord32# i)
instance From Word16 Word64 where
from (W16# i) = wordToWord64 (W# (word16ToWord# i))
instance From Word16 Word128 where
from (W16# i) = Word128 0 (wordToWord64 $ W# (word16ToWord# i))
instance From Word16 Word256 where
from (W16# i) = Word256 0 0 0 (wordToWord64 $ W# (word16ToWord# i))
instance From Word16 Word where
from (W16# i) = W# (word16ToWord# i)
instance From Word16 Int32 where
from (W16# w) = I32# (intToInt32# (word2Int# (word16ToWord# w)))
instance From Word16 Int64 where
from (W16# w) = intToInt64 (I# (word2Int# (word16ToWord# w)))
instance From Word16 Int where
from (W16# w) = I# (word2Int# (word16ToWord# w))
instance From Word32 Word64 where
from (W32# i) = wordToWord64 (W# (word32ToWord# i))
instance From Word32 Word128 where
from (W32# i) = Word128 0 (wordToWord64 $ W# (word32ToWord# i))
instance From Word32 Word256 where
from (W32# i) = Word256 0 0 0 (wordToWord64 $ W# (word32ToWord# i))
instance From Word32 Word where
from (W32# i) = W# (word32ToWord# i)
instance From Word32 Int64 where
from (W32# w) = intToInt64 (I# (word2Int# (word32ToWord# w)))
instance From Word32 Int where
from (W32# w) = I# (word2Int# (word32ToWord# w))
instance From Word64 Word128 where
from w = Word128 0 w
instance From Word64 Word256 where
from w = Word256 0 0 0 w
instance From Word Word64 where
from = wordToWord64
-- Simple prelude types
instance From (Maybe a) (Either () a) where
from (Just x) = Right x
from Nothing = Left ()
-- basic basement types
instance From (CountOf ty) Int where
from (CountOf n) = n
instance From (CountOf ty) Word where
-- here it is ok to cast the underlying `Int` held by `CountOf` to a `Word`
-- as the `Int` should never hold a negative value.
from (CountOf n) = cast n
instance From Word (Offset ty) where
from w = Offset (cast w)
instance TryFrom Int (Offset ty) where
tryFrom i
| i < 0 = Nothing
| otherwise = Just (Offset i)
instance TryFrom Int (CountOf ty) where
tryFrom i
| i < 0 = Nothing
| otherwise = Just (CountOf i)
instance From Word (CountOf ty) where
from w = CountOf (cast w)
instance From (Either a b) (These a b) where
from (Left a) = This a
from (Right b) = That b
instance From Word128 Word256 where
from (Word128 a b) = Word256 0 0 a b
-- basement instances
-- uarrays
instance PrimType ty => From (Block.Block ty) (UArray.UArray ty) where
from = UArray.fromBlock
instance PrimType ty => From (BoxArray.Array ty) (UArray.UArray ty) where
from = BoxArray.mapToUnboxed id
-- blocks
instance PrimType ty => From (UArray.UArray ty) (Block.Block ty) where
from = UArray.toBlock
instance PrimType ty => From (BoxArray.Array ty) (Block.Block ty) where
from = UArray.toBlock . BoxArray.mapToUnboxed id
-- boxed array
instance PrimType ty => From (UArray.UArray ty) (BoxArray.Array ty) where
from = BoxArray.mapFromUnboxed id
instance From String.String (UArray.UArray Word8) where
from = String.toBytes String.UTF8
instance From AsciiString.AsciiString String.String where
from = String.fromBytesUnsafe . UArray.unsafeRecast . AsciiString.toBytes
instance From AsciiString.AsciiString (UArray.UArray Word8) where
from = UArray.unsafeRecast . AsciiString.toBytes
instance TryFrom (UArray.UArray Word8) String.String where
tryFrom arr = case String.fromBytes String.UTF8 arr of
(s, Nothing, _) -> Just s
(_, Just _, _) -> Nothing
#if __GLASGOW_HASKELL__ >= 800
instance From (BlockN.BlockN n ty) (Block.Block ty) where
from = BlockN.toBlock
instance (PrimType a, PrimType b, KnownNat n, KnownNat m, ((PrimSize b) Basement.Nat.* m) ~ ((PrimSize a) Basement.Nat.* n))
=> From (BlockN.BlockN n a) (BlockN.BlockN m b) where
from = BlockN.cast
instance (NatWithinBound Int n, PrimType ty) => From (BlockN.BlockN n ty) (UArray.UArray ty) where
from = UArray.fromBlock . BlockN.toBlock
instance (NatWithinBound Int n, PrimType ty) => From (BlockN.BlockN n ty) (BoxArray.Array ty) where
from = BoxArray.mapFromUnboxed id . UArray.fromBlock . BlockN.toBlock
instance (NatWithinBound (CountOf ty) n, KnownNat n, PrimType ty)
=> TryFrom (Block.Block ty) (BlockN.BlockN n ty) where
tryFrom = BlockN.toBlockN
instance (NatWithinBound (CountOf ty) n, KnownNat n, PrimType ty)
=> TryFrom (UArray.UArray ty) (BlockN.BlockN n ty) where
tryFrom = BlockN.toBlockN . UArray.toBlock
instance (NatWithinBound (CountOf ty) n, KnownNat n, PrimType ty)
=> TryFrom (BoxArray.Array ty) (BlockN.BlockN n ty) where
tryFrom = BlockN.toBlockN . UArray.toBlock . BoxArray.mapToUnboxed id
instance (KnownNat n, NatWithinBound Word8 n) => From (Zn64 n) Word8 where
#if __GLASGOW_HASKELL__ >= 904
from = narrow . unZn64 where narrow (W64# w) = W8# (wordToWord8# (word64ToWord# (GHC.Prim.word64ToWord# w)))
#else
from = narrow . unZn64 where narrow (W64# w) = W8# (wordToWord8# (word64ToWord# w))
#endif
instance (KnownNat n, NatWithinBound Word16 n) => From (Zn64 n) Word16 where
#if __GLASGOW_HASKELL__ >= 904
from = narrow . unZn64 where narrow (W64# w) = W16# (wordToWord16# (word64ToWord# (GHC.Prim.word64ToWord# w)))
#else
from = narrow . unZn64 where narrow (W64# w) = W16# (wordToWord16# (word64ToWord# w))
#endif
instance (KnownNat n, NatWithinBound Word32 n) => From (Zn64 n) Word32 where
#if __GLASGOW_HASKELL__ >= 904
from = narrow . unZn64 where narrow (W64# w) = W32# (wordToWord32# (word64ToWord# (GHC.Prim.word64ToWord# w)))
#else
from = narrow . unZn64 where narrow (W64# w) = W32# (wordToWord32# (word64ToWord# w))
#endif
instance From (Zn64 n) Word64 where
from = unZn64
instance From (Zn64 n) Word128 where
from = from . unZn64
instance From (Zn64 n) Word256 where
from = from . unZn64
instance (KnownNat n, NatWithinBound Word8 n) => From (Zn n) Word8 where
#if __GLASGOW_HASKELL__ >= 904
from = narrow . naturalToWord64 . unZn where narrow (W64# w) = W8# (wordToWord8# (word64ToWord# (GHC.Prim.word64ToWord# w)))
#else
from = narrow . naturalToWord64 . unZn where narrow (W64# w) = W8# (wordToWord8# (word64ToWord# w))
#endif
instance (KnownNat n, NatWithinBound Word16 n) => From (Zn n) Word16 where
#if __GLASGOW_HASKELL__ >= 904
from = narrow . naturalToWord64 . unZn where narrow (W64# w) = W16# (wordToWord16# (word64ToWord# (GHC.Prim.word64ToWord# w)))
#else
from = narrow . naturalToWord64 . unZn where narrow (W64# w) = W16# (wordToWord16# (word64ToWord# w))
#endif
instance (KnownNat n, NatWithinBound Word32 n) => From (Zn n) Word32 where
#if __GLASGOW_HASKELL__ >= 904
from = narrow . naturalToWord64 . unZn where narrow (W64# w) = W32# (wordToWord32# (word64ToWord# (GHC.Prim.word64ToWord# w)))
#else
from = narrow . naturalToWord64 . unZn where narrow (W64# w) = W32# (wordToWord32# (word64ToWord# w))
#endif
instance (KnownNat n, NatWithinBound Word64 n) => From (Zn n) Word64 where
from = naturalToWord64 . unZn
instance (KnownNat n, NatWithinBound Word128 n) => From (Zn n) Word128 where
from = Word128.fromNatural . unZn
instance (KnownNat n, NatWithinBound Word256 n) => From (Zn n) Word256 where
from = Word256.fromNatural . unZn
instance (KnownNat n, NatWithinBound Word64 n) => From (Zn n) (Zn64 n) where
from = zn64 . naturalToWord64 . unZn
instance KnownNat n => From (Zn64 n) (Zn n) where
from = zn . from . unZn64
naturalToWord64 :: Natural -> Word64
naturalToWord64 = Prelude.fromIntegral
#endif