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GHC.Prim

Portability | non-portable (GHC extensions)
Stability | internal
Maintainer | cvs-ghc@haskell.org

Contents

The word size story.
Char#
Int#
Word#
Narrowings
Int64#
Word64#
Integer#
Double#
Float#
Arrays
Byte Arrays
Addr#
Mutable variables
Exceptions
STM-accessible Mutable Variables
Synchronized Mutable Variables
Delay/wait operations
Concurrency primitives
Weak pointers
Stable pointers and names
Unsafe pointer equality
Parallelism
Tag to enum stuff
Bytecode operations
Etc

Description
GHC's primitive types and operations.
Synopsis

data Char#
gtChar# :: Char# -> Char# -> Bool
geChar# :: Char# -> Char# -> Bool
eqChar# :: Char# -> Char# -> Bool
neChar# :: Char# -> Char# -> Bool
ltChar# :: Char# -> Char# -> Bool
leChar# :: Char# -> Char# -> Bool
ord# :: Char# -> Int#
data Int#
(+#) :: Int# -> Int# -> Int#
(-#) :: Int# -> Int# -> Int#
(*#) :: Int# -> Int# -> Int#
mulIntMayOflo# :: Int# -> Int# -> Int#
quotInt# :: Int# -> Int# -> Int#
remInt# :: Int# -> Int# -> Int#
gcdInt# :: Int# -> Int# -> Int#
negateInt# :: Int# -> Int#
addIntC# :: Int# -> Int# -> (#Int#, Int##)
subIntC# :: Int# -> Int# -> (#Int#, Int##)
(>#) :: Int# -> Int# -> Bool
(>=#) :: Int# -> Int# -> Bool
(==#) :: Int# -> Int# -> Bool
(/=#) :: Int# -> Int# -> Bool
(<#) :: Int# -> Int# -> Bool
(<=#) :: Int# -> Int# -> Bool
chr# :: Int# -> Char#
int2Word# :: Int# -> Word#
int2Float# :: Int# -> Float#
int2Double# :: Int# -> Double#
int2Integer# :: Int# -> (#Int#, ByteArr##)
uncheckedIShiftL# :: Int# -> Int# -> Int#
uncheckedIShiftRA# :: Int# -> Int# -> Int#
uncheckedIShiftRL# :: Int# -> Int# -> Int#
data Word#
plusWord# :: Word# -> Word# -> Word#
minusWord# :: Word# -> Word# -> Word#
timesWord# :: Word# -> Word# -> Word#
quotWord# :: Word# -> Word# -> Word#
remWord# :: Word# -> Word# -> Word#
and# :: Word# -> Word# -> Word#
or# :: Word# -> Word# -> Word#
xor# :: Word# -> Word# -> Word#
not# :: Word# -> Word#
uncheckedShiftL# :: Word# -> Int# -> Word#
uncheckedShiftRL# :: Word# -> Int# -> Word#
word2Int# :: Word# -> Int#
word2Integer# :: Word# -> (#Int#, ByteArr##)
gtWord# :: Word# -> Word# -> Bool
geWord# :: Word# -> Word# -> Bool
eqWord# :: Word# -> Word# -> Bool
neWord# :: Word# -> Word# -> Bool
ltWord# :: Word# -> Word# -> Bool
leWord# :: Word# -> Word# -> Bool
narrow8Int# :: Int# -> Int#
narrow16Int# :: Int# -> Int#
narrow32Int# :: Int# -> Int#
narrow8Word# :: Word# -> Word#
narrow16Word# :: Word# -> Word#
narrow32Word# :: Word# -> Word#
data Int64#
int64ToInteger# :: Int64# -> (#Int#, ByteArr##)
data Word64#
word64ToInteger# :: Word64# -> (#Int#, ByteArr##)
plusInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
minusInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
timesInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
gcdInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
gcdIntegerInt# :: Int# -> ByteArr# -> Int# -> Int#
divExactInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
quotInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
remInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
cmpInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> Int#
cmpIntegerInt# :: Int# -> ByteArr# -> Int# -> Int#
quotRemInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr#, Int#, ByteArr##)
divModInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr#, Int#, ByteArr##)
integer2Int# :: Int# -> ByteArr# -> Int#
integer2Word# :: Int# -> ByteArr# -> Word#
andInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
orInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
xorInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
complementInteger# :: Int# -> ByteArr# -> (#Int#, ByteArr##)
data Double#
(>##) :: Double# -> Double# -> Bool
(>=##) :: Double# -> Double# -> Bool
(==##) :: Double# -> Double# -> Bool
(/=##) :: Double# -> Double# -> Bool
(<##) :: Double# -> Double# -> Bool
(<=##) :: Double# -> Double# -> Bool
(+##) :: Double# -> Double# -> Double#
(-##) :: Double# -> Double# -> Double#
(*##) :: Double# -> Double# -> Double#
(/##) :: Double# -> Double# -> Double#
negateDouble# :: Double# -> Double#
double2Int# :: Double# -> Int#
double2Float# :: Double# -> Float#
expDouble# :: Double# -> Double#
logDouble# :: Double# -> Double#
sqrtDouble# :: Double# -> Double#
sinDouble# :: Double# -> Double#
cosDouble# :: Double# -> Double#
tanDouble# :: Double# -> Double#
asinDouble# :: Double# -> Double#
acosDouble# :: Double# -> Double#
atanDouble# :: Double# -> Double#
sinhDouble# :: Double# -> Double#
coshDouble# :: Double# -> Double#
tanhDouble# :: Double# -> Double#
(**##) :: Double# -> Double# -> Double#
decodeDouble# :: Double# -> (#Int#, Int#, ByteArr##)
data Float#
gtFloat# :: Float# -> Float# -> Bool
geFloat# :: Float# -> Float# -> Bool
eqFloat# :: Float# -> Float# -> Bool
neFloat# :: Float# -> Float# -> Bool
ltFloat# :: Float# -> Float# -> Bool
leFloat# :: Float# -> Float# -> Bool
plusFloat# :: Float# -> Float# -> Float#
minusFloat# :: Float# -> Float# -> Float#
timesFloat# :: Float# -> Float# -> Float#
divideFloat# :: Float# -> Float# -> Float#
negateFloat# :: Float# -> Float#
float2Int# :: Float# -> Int#
expFloat# :: Float# -> Float#
logFloat# :: Float# -> Float#
sqrtFloat# :: Float# -> Float#
sinFloat# :: Float# -> Float#
cosFloat# :: Float# -> Float#
tanFloat# :: Float# -> Float#
asinFloat# :: Float# -> Float#
acosFloat# :: Float# -> Float#
atanFloat# :: Float# -> Float#
sinhFloat# :: Float# -> Float#
coshFloat# :: Float# -> Float#
tanhFloat# :: Float# -> Float#
powerFloat# :: Float# -> Float# -> Float#
float2Double# :: Float# -> Double#
decodeFloat# :: Float# -> (#Int#, Int#, ByteArr##)
data Array# a
data MutArr# s a
newArray# :: Int# -> a -> State# s -> (#State# s, MutArr# s a#)
sameMutableArray# :: MutArr# s a -> MutArr# s a -> Bool
readArray# :: MutArr# s a -> Int# -> State# s -> (#State# s, a#)
writeArray# :: MutArr# s a -> Int# -> a -> State# s -> State# s
indexArray# :: Array# a -> Int# -> (#a#)
unsafeFreezeArray# :: MutArr# s a -> State# s -> (#State# s, Array# a#)
unsafeThawArray# :: Array# a -> State# s -> (#State# s, MutArr# s a#)
data ByteArr#
data MutByteArr# s
newByteArray# :: Int# -> State# s -> (#State# s, MutByteArr# s#)
newPinnedByteArray# :: Int# -> State# s -> (#State# s, MutByteArr# s#)
byteArrayContents# :: ByteArr# -> Addr#
sameMutableByteArray# :: MutByteArr# s -> MutByteArr# s -> Bool
unsafeFreezeByteArray# :: MutByteArr# s -> State# s -> (#State# s, ByteArr##)
sizeofByteArray# :: ByteArr# -> Int#
sizeofMutableByteArray# :: MutByteArr# s -> Int#
indexCharArray# :: ByteArr# -> Int# -> Char#
indexWideCharArray# :: ByteArr# -> Int# -> Char#
indexIntArray# :: ByteArr# -> Int# -> Int#
indexWordArray# :: ByteArr# -> Int# -> Word#
indexAddrArray# :: ByteArr# -> Int# -> Addr#
indexFloatArray# :: ByteArr# -> Int# -> Float#
indexDoubleArray# :: ByteArr# -> Int# -> Double#
indexStablePtrArray# :: ByteArr# -> Int# -> StablePtr# a
indexInt8Array# :: ByteArr# -> Int# -> Int#
indexInt16Array# :: ByteArr# -> Int# -> Int#
indexInt32Array# :: ByteArr# -> Int# -> Int#
indexInt64Array# :: ByteArr# -> Int# -> Int64#
indexWord8Array# :: ByteArr# -> Int# -> Word#
indexWord16Array# :: ByteArr# -> Int# -> Word#
indexWord32Array# :: ByteArr# -> Int# -> Word#
indexWord64Array# :: ByteArr# -> Int# -> Word64#
readCharArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Char##)
readWideCharArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Char##)
readIntArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readWordArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readAddrArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Addr##)
readFloatArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Float##)
readDoubleArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Double##)
readStablePtrArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, StablePtr# a#)
readInt8Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readInt16Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readInt32Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readInt64Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int64##)
readWord8Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readWord16Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readWord32Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readWord64Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word64##)
writeCharArray# :: MutByteArr# s -> Int# -> Char# -> State# s -> State# s
writeWideCharArray# :: MutByteArr# s -> Int# -> Char# -> State# s -> State# s
writeIntArray# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeWordArray# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeAddrArray# :: MutByteArr# s -> Int# -> Addr# -> State# s -> State# s
writeFloatArray# :: MutByteArr# s -> Int# -> Float# -> State# s -> State# s
writeDoubleArray# :: MutByteArr# s -> Int# -> Double# -> State# s -> State# s
writeStablePtrArray# :: MutByteArr# s -> Int# -> StablePtr# a -> State# s -> State# s
writeInt8Array# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeInt16Array# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeInt32Array# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeInt64Array# :: MutByteArr# s -> Int# -> Int64# -> State# s -> State# s
writeWord8Array# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeWord16Array# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeWord32Array# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeWord64Array# :: MutByteArr# s -> Int# -> Word64# -> State# s -> State# s
data Addr#
nullAddr# :: Addr#
plusAddr# :: Addr# -> Int# -> Addr#
minusAddr# :: Addr# -> Addr# -> Int#
remAddr# :: Addr# -> Int# -> Int#
addr2Int# :: Addr# -> Int#
int2Addr# :: Int# -> Addr#
gtAddr# :: Addr# -> Addr# -> Bool
geAddr# :: Addr# -> Addr# -> Bool
eqAddr# :: Addr# -> Addr# -> Bool
neAddr# :: Addr# -> Addr# -> Bool
ltAddr# :: Addr# -> Addr# -> Bool
leAddr# :: Addr# -> Addr# -> Bool
indexCharOffAddr# :: Addr# -> Int# -> Char#
indexWideCharOffAddr# :: Addr# -> Int# -> Char#
indexIntOffAddr# :: Addr# -> Int# -> Int#
indexWordOffAddr# :: Addr# -> Int# -> Word#
indexAddrOffAddr# :: Addr# -> Int# -> Addr#
indexFloatOffAddr# :: Addr# -> Int# -> Float#
indexDoubleOffAddr# :: Addr# -> Int# -> Double#
indexStablePtrOffAddr# :: Addr# -> Int# -> StablePtr# a
indexInt8OffAddr# :: Addr# -> Int# -> Int#
indexInt16OffAddr# :: Addr# -> Int# -> Int#
indexInt32OffAddr# :: Addr# -> Int# -> Int#
indexInt64OffAddr# :: Addr# -> Int# -> Int64#
indexWord8OffAddr# :: Addr# -> Int# -> Word#
indexWord16OffAddr# :: Addr# -> Int# -> Word#
indexWord32OffAddr# :: Addr# -> Int# -> Word#
indexWord64OffAddr# :: Addr# -> Int# -> Word64#
readCharOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Char##)
readWideCharOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Char##)
readIntOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readWordOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readAddrOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Addr##)
readFloatOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Float##)
readDoubleOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Double##)
readStablePtrOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, StablePtr# a#)
readInt8OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readInt16OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readInt32OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readInt64OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int64##)
readWord8OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readWord16OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readWord32OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readWord64OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word64##)
writeCharOffAddr# :: Addr# -> Int# -> Char# -> State# s -> State# s
writeWideCharOffAddr# :: Addr# -> Int# -> Char# -> State# s -> State# s
writeIntOffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeWordOffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeAddrOffAddr# :: Addr# -> Int# -> Addr# -> State# s -> State# s
writeFloatOffAddr# :: Addr# -> Int# -> Float# -> State# s -> State# s
writeDoubleOffAddr# :: Addr# -> Int# -> Double# -> State# s -> State# s
writeStablePtrOffAddr# :: Addr# -> Int# -> StablePtr# a -> State# s -> State# s
writeInt8OffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeInt16OffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeInt32OffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeInt64OffAddr# :: Addr# -> Int# -> Int64# -> State# s -> State# s
writeWord8OffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeWord16OffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeWord32OffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeWord64OffAddr# :: Addr# -> Int# -> Word64# -> State# s -> State# s
data MutVar# s a
newMutVar# :: a -> State# s -> (#State# s, MutVar# s a#)
readMutVar# :: MutVar# s a -> State# s -> (#State# s, a#)
writeMutVar# :: MutVar# s a -> a -> State# s -> State# s
sameMutVar# :: MutVar# s a -> MutVar# s a -> Bool
atomicModifyMutVar# :: MutVar# s a -> (a -> b) -> State# s -> (#State# s, c#)
catch# :: (State# RealWorld -> (#State# RealWorld, a#)) -> (b -> State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
raise# :: a -> b
raiseIO# :: a -> State# RealWorld -> (#State# RealWorld, b#)
blockAsyncExceptions# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
unblockAsyncExceptions# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
data TVar# s a
atomically# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
retry# :: State# RealWorld -> (#State# RealWorld, a#)
catchRetry# :: (State# RealWorld -> (#State# RealWorld, a#)) -> (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
catchSTM# :: (State# RealWorld -> (#State# RealWorld, a#)) -> (b -> State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
newTVar# :: a -> State# s -> (#State# s, TVar# s a#)
readTVar# :: TVar# s a -> State# s -> (#State# s, a#)
writeTVar# :: TVar# s a -> a -> State# s -> State# s
sameTVar# :: TVar# s a -> TVar# s a -> Bool
data MVar# s a
newMVar# :: State# s -> (#State# s, MVar# s a#)
takeMVar# :: MVar# s a -> State# s -> (#State# s, a#)
tryTakeMVar# :: MVar# s a -> State# s -> (#State# s, Int#, a#)
putMVar# :: MVar# s a -> a -> State# s -> State# s
tryPutMVar# :: MVar# s a -> a -> State# s -> (#State# s, Int##)
sameMVar# :: MVar# s a -> MVar# s a -> Bool
isEmptyMVar# :: MVar# s a -> State# s -> (#State# s, Int##)
delay# :: Int# -> State# s -> State# s
waitRead# :: Int# -> State# s -> State# s
waitWrite# :: Int# -> State# s -> State# s
data State# s
data RealWorld
data ThreadId#
fork# :: a -> State# RealWorld -> (#State# RealWorld, ThreadId##)
forkOn# :: Int# -> a -> State# RealWorld -> (#State# RealWorld, ThreadId##)
killThread# :: ThreadId# -> a -> State# RealWorld -> State# RealWorld
yield# :: State# RealWorld -> State# RealWorld
myThreadId# :: State# RealWorld -> (#State# RealWorld, ThreadId##)
labelThread# :: ThreadId# -> Addr# -> State# RealWorld -> State# RealWorld
isCurrentThreadBound# :: State# RealWorld -> (#State# RealWorld, Int##)
noDuplicate# :: State# RealWorld -> State# RealWorld
data Weak# b
mkWeak# :: o -> b -> c -> State# RealWorld -> (#State# RealWorld, Weak# b#)
deRefWeak# :: Weak# a -> State# RealWorld -> (#State# RealWorld, Int#, a#)
finalizeWeak# :: Weak# a -> State# RealWorld -> (#State# RealWorld, Int#, State# RealWorld -> (#State# RealWorld, ()#)#)
touch# :: o -> State# RealWorld -> State# RealWorld
data StablePtr# a
data StableName# a
makeStablePtr# :: a -> State# RealWorld -> (#State# RealWorld, StablePtr# a#)
deRefStablePtr# :: StablePtr# a -> State# RealWorld -> (#State# RealWorld, a#)
eqStablePtr# :: StablePtr# a -> StablePtr# a -> Int#
makeStableName# :: a -> State# RealWorld -> (#State# RealWorld, StableName# a#)
eqStableName# :: StableName# a -> StableName# a -> Int#
stableNameToInt# :: StableName# a -> Int#
reallyUnsafePtrEquality# :: a -> a -> Int#
par# :: a -> Int#
parGlobal# :: a -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parLocal# :: a -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parAt# :: b -> a -> Int# -> Int# -> Int# -> Int# -> c -> Int#
parAtAbs# :: a -> Int# -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parAtRel# :: a -> Int# -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parAtForNow# :: b -> a -> Int# -> Int# -> Int# -> Int# -> c -> Int#
dataToTag# :: a -> Int#
tagToEnum# :: Int# -> a
data BCO#
addrToHValue# :: Addr# -> (#a#)
mkApUpd0# :: BCO# -> (#a#)
newBCO# :: ByteArr# -> ByteArr# -> Array# a -> ByteArr# -> Int# -> ByteArr# -> State# s -> (#State# s, BCO##)
seq :: a -> b -> b
inline :: a -> a
lazy :: a -> a
data Any a
unsafeCoerce# :: a -> b

The word size story.

Haskell98 specifies that signed integers (type `Int`) must contain at least 30 bits. GHC always implements `Int` using the primitive type `Int#`, whose size equals the `MachDeps.h` constant `WORD_SIZE_IN_BITS`. This is normally set based on the `config.h` parameter `SIZEOF_HSWORD`, i.e., 32 bits on 32-bit machines, 64 bits on 64-bit machines. However, it can also be explicitly set to a smaller number, e.g., 31 bits, to allow the possibility of using tag bits. Currently GHC itself has only 32-bit and 64-bit variants, but 30 or 31-bit code can be exported as an external core file for use in other back ends.

GHC also implements a primitive unsigned integer type `Word#` which always has the same number of bits as `Int#`.

In addition, GHC supports families of explicit-sized integers and words at 8, 16, 32, and 64 bits, with the usual arithmetic operations, comparisons, and a range of conversions. The 8-bit and 16-bit sizes are always represented as `Int#` and `Word#`, and the operations implemented in terms of the the primops on these types, with suitable range restrictions on the results (using the `narrow$n$Int#` and `narrow$n$Word#` families of primops. The 32-bit sizes are represented using `Int#` and `Word#` when `WORD_SIZE_IN_BITS` $geq$ 32; otherwise, these are represented using distinct primitive types `Int32#` and `Word32#`. These (when needed) have a complete set of corresponding operations; however, nearly all of these are implemented as external C functions rather than as primops. Exactly the same story applies to the 64-bit sizes. All of these details are hidden under the `PrelInt` and `PrelWord` modules, which use `#if`-defs to invoke the appropriate types and operators.

Word size also matters for the families of primops for indexing/reading/writing fixed-size quantities at offsets from an array base, address, or foreign pointer. Here, a slightly different approach is taken. The names of these primops are fixed, but their types vary according to the value of `WORD_SIZE_IN_BITS`. For example, if word size is at least 32 bits then an operator like `indexInt32Array#` has type `ByteArr# -> Int# -> Int#`; otherwise it has type `ByteArr# -> Int# -> Int32#`. This approach confines the necessary `#if`-defs to this file; no conditional compilation is needed in the files that expose these primops.

Finally, there are strongly deprecated primops for coercing between `Addr#`, the primitive type of machine addresses, and `Int#`. These are pretty bogus anyway, but will work on existing 32-bit and 64-bit GHC targets; they are completely bogus when tag bits are used in `Int#`, so are not available in this case.

Char#
Operations on 31-bit characters.
data Char#

gtChar# :: Char# -> Char# -> Bool
geChar# :: Char# -> Char# -> Bool
eqChar# :: Char# -> Char# -> Bool
neChar# :: Char# -> Char# -> Bool
ltChar# :: Char# -> Char# -> Bool
leChar# :: Char# -> Char# -> Bool
ord# :: Char# -> Int#
Int#
Operations on native-size integers (30+ bits).
data Int#

(+#) :: Int# -> Int# -> Int#
(-#) :: Int# -> Int# -> Int#
(*#) :: Int# -> Int# -> Int#
Low word of signed integer multiply.
mulIntMayOflo# :: Int# -> Int# -> Int#

Return non-zero if there is any possibility that the upper word of a signed integer multiply might contain useful information. Return zero only if you are completely sure that no overflow can occur. On a 32-bit platform, the recommmended implementation is to do a 32 x 32 -> 64 signed multiply, and subtract result[63:32] from (result[31] >>signed 31). If this is zero, meaning that the upper word is merely a sign extension of the lower one, no overflow can occur.

On a 64-bit platform it is not always possible to acquire the top 64 bits of the result. Therefore, a recommended implementation is to take the absolute value of both operands, and return 0 iff bits[63:31] of them are zero, since that means that their magnitudes fit within 31 bits, so the magnitude of the product must fit into 62 bits.

If in doubt, return non-zero, but do make an effort to create the correct answer for small args, since otherwise the performance of `(*) :: Integer -> Integer -> Integer` will be poor.

quotInt# :: Int# -> Int# -> Int#
Rounds towards zero.
remInt# :: Int# -> Int# -> Int#
Satisfies `(quotInt# x y) *# y +# (remInt# x y) == x`.
gcdInt# :: Int# -> Int# -> Int#
negateInt# :: Int# -> Int#
addIntC# :: Int# -> Int# -> (#Int#, Int##)
Add with carry. First member of result is (wrapped) sum; second member is 0 iff no overflow occured.
subIntC# :: Int# -> Int# -> (#Int#, Int##)
Subtract with carry. First member of result is (wrapped) difference; second member is 0 iff no overflow occured.
(>#) :: Int# -> Int# -> Bool
(>=#) :: Int# -> Int# -> Bool
(==#) :: Int# -> Int# -> Bool
(/=#) :: Int# -> Int# -> Bool
(<#) :: Int# -> Int# -> Bool
(<=#) :: Int# -> Int# -> Bool
chr# :: Int# -> Char#
int2Word# :: Int# -> Word#
int2Float# :: Int# -> Float#
int2Double# :: Int# -> Double#
int2Integer# :: Int# -> (#Int#, ByteArr##)
uncheckedIShiftL# :: Int# -> Int# -> Int#
Shift left. Result undefined if shift amount is not in the range 0 to word size - 1 inclusive.
uncheckedIShiftRA# :: Int# -> Int# -> Int#
Shift right arithmetic. Result undefined if shift amount is not in the range 0 to word size - 1 inclusive.
uncheckedIShiftRL# :: Int# -> Int# -> Int#
Shift right logical. Result undefined if shift amount is not in the range 0 to word size - 1 inclusive.
Word#
Operations on native-sized unsigned words (30+ bits).
data Word#

plusWord# :: Word# -> Word# -> Word#
minusWord# :: Word# -> Word# -> Word#
timesWord# :: Word# -> Word# -> Word#
quotWord# :: Word# -> Word# -> Word#
remWord# :: Word# -> Word# -> Word#
and# :: Word# -> Word# -> Word#
or# :: Word# -> Word# -> Word#
xor# :: Word# -> Word# -> Word#
not# :: Word# -> Word#
uncheckedShiftL# :: Word# -> Int# -> Word#
Shift left logical. Result undefined if shift amount is not in the range 0 to word size - 1 inclusive.
uncheckedShiftRL# :: Word# -> Int# -> Word#
Shift right logical. Result undefined if shift amount is not in the range 0 to word size - 1 inclusive.
word2Int# :: Word# -> Int#
word2Integer# :: Word# -> (#Int#, ByteArr##)
gtWord# :: Word# -> Word# -> Bool
geWord# :: Word# -> Word# -> Bool
eqWord# :: Word# -> Word# -> Bool
neWord# :: Word# -> Word# -> Bool
ltWord# :: Word# -> Word# -> Bool
leWord# :: Word# -> Word# -> Bool
Narrowings
Explicit narrowing of native-sized ints or words.
narrow8Int# :: Int# -> Int#
narrow16Int# :: Int# -> Int#
narrow32Int# :: Int# -> Int#
narrow8Word# :: Word# -> Word#
narrow16Word# :: Word# -> Word#
narrow32Word# :: Word# -> Word#
Int64#
Operations on 64-bit unsigned words. This type is only used if plain `Int#` has less than 64 bits. In any case, the operations are not primops; they are implemented (if needed) as ccalls instead.
data Int64#

int64ToInteger# :: Int64# -> (#Int#, ByteArr##)
Word64#
Operations on 64-bit unsigned words. This type is only used if plain `Word#` has less than 64 bits. In any case, the operations are not primops; they are implemented (if needed) as ccalls instead.
data Word64#

word64ToInteger# :: Word64# -> (#Int#, ByteArr##)
Integer#

Operations on arbitrary-precision integers. These operations are implemented via the GMP package. An integer is represented as a pair consisting of an `Int#` representing the number of 'limbs' in use and the sign, and a `ByteArr#` containing the 'limbs' themselves. Such pairs are returned as unboxed pairs, but must be passed as separate components.

For .NET these operations are implemented by foreign imports, so the primops are omitted.

plusInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
minusInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
timesInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
gcdInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
Greatest common divisor.
gcdIntegerInt# :: Int# -> ByteArr# -> Int# -> Int#
Greatest common divisor, where second argument is an ordinary `Int#`.
divExactInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
Divisor is guaranteed to be a factor of dividend.
quotInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
Rounds towards zero.
remInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
Satisfies `plusInteger# (timesInteger# (quotInteger# x y) y) (remInteger# x y) == x`.
cmpInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> Int#
Returns -1,0,1 according as first argument is less than, equal to, or greater than second argument.
cmpIntegerInt# :: Int# -> ByteArr# -> Int# -> Int#
Returns -1,0,1 according as first argument is less than, equal to, or greater than second argument, which is an ordinary Int#.
quotRemInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr#, Int#, ByteArr##)
Compute quot and rem simulaneously.
divModInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr#, Int#, ByteArr##)
Compute div and mod simultaneously, where div rounds towards negative infinity and`(q,r) = divModInteger#(x,y)` implies `plusInteger# (timesInteger# q y) r = x`.
integer2Int# :: Int# -> ByteArr# -> Int#
integer2Word# :: Int# -> ByteArr# -> Word#
andInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
orInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
xorInteger# :: Int# -> ByteArr# -> Int# -> ByteArr# -> (#Int#, ByteArr##)
complementInteger# :: Int# -> ByteArr# -> (#Int#, ByteArr##)
Double#
Operations on double-precision (64 bit) floating-point numbers.
data Double#

(>##) :: Double# -> Double# -> Bool
(>=##) :: Double# -> Double# -> Bool
(==##) :: Double# -> Double# -> Bool
(/=##) :: Double# -> Double# -> Bool
(<##) :: Double# -> Double# -> Bool
(<=##) :: Double# -> Double# -> Bool
(+##) :: Double# -> Double# -> Double#
(-##) :: Double# -> Double# -> Double#
(*##) :: Double# -> Double# -> Double#
(/##) :: Double# -> Double# -> Double#
negateDouble# :: Double# -> Double#
double2Int# :: Double# -> Int#
double2Float# :: Double# -> Float#
expDouble# :: Double# -> Double#
logDouble# :: Double# -> Double#
sqrtDouble# :: Double# -> Double#
sinDouble# :: Double# -> Double#
cosDouble# :: Double# -> Double#
tanDouble# :: Double# -> Double#
asinDouble# :: Double# -> Double#
acosDouble# :: Double# -> Double#
atanDouble# :: Double# -> Double#
sinhDouble# :: Double# -> Double#
coshDouble# :: Double# -> Double#
tanhDouble# :: Double# -> Double#
(**##) :: Double# -> Double# -> Double#
Exponentiation.
decodeDouble# :: Double# -> (#Int#, Int#, ByteArr##)
Convert to arbitrary-precision integer. First `Int#` in result is the exponent; second `Int#` and `ByteArr#` represent an `Integer#` holding the mantissa.
Float#
Operations on single-precision (32-bit) floating-point numbers.
data Float#

gtFloat# :: Float# -> Float# -> Bool
geFloat# :: Float# -> Float# -> Bool
eqFloat# :: Float# -> Float# -> Bool
neFloat# :: Float# -> Float# -> Bool
ltFloat# :: Float# -> Float# -> Bool
leFloat# :: Float# -> Float# -> Bool
plusFloat# :: Float# -> Float# -> Float#
minusFloat# :: Float# -> Float# -> Float#
timesFloat# :: Float# -> Float# -> Float#
divideFloat# :: Float# -> Float# -> Float#
negateFloat# :: Float# -> Float#
float2Int# :: Float# -> Int#
expFloat# :: Float# -> Float#
logFloat# :: Float# -> Float#
sqrtFloat# :: Float# -> Float#
sinFloat# :: Float# -> Float#
cosFloat# :: Float# -> Float#
tanFloat# :: Float# -> Float#
asinFloat# :: Float# -> Float#
acosFloat# :: Float# -> Float#
atanFloat# :: Float# -> Float#
sinhFloat# :: Float# -> Float#
coshFloat# :: Float# -> Float#
tanhFloat# :: Float# -> Float#
powerFloat# :: Float# -> Float# -> Float#
float2Double# :: Float# -> Double#
decodeFloat# :: Float# -> (#Int#, Int#, ByteArr##)
Convert to arbitrary-precision integer. First `Int#` in result is the exponent; second `Int#` and `ByteArr#` represent an `Integer#` holding the mantissa.
Arrays
Operations on `Array#`.
data Array# a

data MutArr# s a

newArray# :: Int# -> a -> State# s -> (#State# s, MutArr# s a#)
Create a new mutable array of specified size (in bytes), in the specified state thread, with each element containing the specified initial value.
sameMutableArray# :: MutArr# s a -> MutArr# s a -> Bool
readArray# :: MutArr# s a -> Int# -> State# s -> (#State# s, a#)
Read from specified index of mutable array. Result is not yet evaluated.
writeArray# :: MutArr# s a -> Int# -> a -> State# s -> State# s
Write to specified index of mutable array.
indexArray# :: Array# a -> Int# -> (#a#)
Read from specified index of immutable array. Result is packaged into an unboxed singleton; the result itself is not yet evaluated.
unsafeFreezeArray# :: MutArr# s a -> State# s -> (#State# s, Array# a#)
Make a mutable array immutable, without copying.
unsafeThawArray# :: Array# a -> State# s -> (#State# s, MutArr# s a#)
Make an immutable array mutable, without copying.
Byte Arrays

Operations on `ByteArray#`. A `ByteArray#` is a just a region of raw memory in the garbage-collected heap, which is not scanned for pointers. It carries its own size (in bytes). There are three sets of operations for accessing byte array contents: index for reading from immutable byte arrays, and read/write for mutable byte arrays. Each set contains operations for a range of useful primitive data types. Each operation takes an offset measured in terms of the size fo the primitive type being read or written.

data ByteArr#

data MutByteArr# s

newByteArray# :: Int# -> State# s -> (#State# s, MutByteArr# s#)
Create a new mutable byte array of specified size (in bytes), in the specified state thread.
newPinnedByteArray# :: Int# -> State# s -> (#State# s, MutByteArr# s#)
Create a mutable byte array that the GC guarantees not to move.
byteArrayContents# :: ByteArr# -> Addr#
Intended for use with pinned arrays; otherwise very unsafe!
sameMutableByteArray# :: MutByteArr# s -> MutByteArr# s -> Bool
unsafeFreezeByteArray# :: MutByteArr# s -> State# s -> (#State# s, ByteArr##)
Make a mutable byte array immutable, without copying.
sizeofByteArray# :: ByteArr# -> Int#
sizeofMutableByteArray# :: MutByteArr# s -> Int#
indexCharArray# :: ByteArr# -> Int# -> Char#
Read 8-bit character; offset in bytes.
indexWideCharArray# :: ByteArr# -> Int# -> Char#
Read 31-bit character; offset in 4-byte words.
indexIntArray# :: ByteArr# -> Int# -> Int#
indexWordArray# :: ByteArr# -> Int# -> Word#
indexAddrArray# :: ByteArr# -> Int# -> Addr#
indexFloatArray# :: ByteArr# -> Int# -> Float#
indexDoubleArray# :: ByteArr# -> Int# -> Double#
indexStablePtrArray# :: ByteArr# -> Int# -> StablePtr# a
indexInt8Array# :: ByteArr# -> Int# -> Int#
indexInt16Array# :: ByteArr# -> Int# -> Int#
indexInt32Array# :: ByteArr# -> Int# -> Int#
indexInt64Array# :: ByteArr# -> Int# -> Int64#
indexWord8Array# :: ByteArr# -> Int# -> Word#
indexWord16Array# :: ByteArr# -> Int# -> Word#
indexWord32Array# :: ByteArr# -> Int# -> Word#
indexWord64Array# :: ByteArr# -> Int# -> Word64#
readCharArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Char##)
Read 8-bit character; offset in bytes.
readWideCharArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Char##)
Read 31-bit character; offset in 4-byte words.
readIntArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readWordArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readAddrArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Addr##)
readFloatArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Float##)
readDoubleArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Double##)
readStablePtrArray# :: MutByteArr# s -> Int# -> State# s -> (#State# s, StablePtr# a#)
readInt8Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readInt16Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readInt32Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int##)
readInt64Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Int64##)
readWord8Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readWord16Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readWord32Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word##)
readWord64Array# :: MutByteArr# s -> Int# -> State# s -> (#State# s, Word64##)
writeCharArray# :: MutByteArr# s -> Int# -> Char# -> State# s -> State# s
Write 8-bit character; offset in bytes.
writeWideCharArray# :: MutByteArr# s -> Int# -> Char# -> State# s -> State# s
Write 31-bit character; offset in 4-byte words.
writeIntArray# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeWordArray# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeAddrArray# :: MutByteArr# s -> Int# -> Addr# -> State# s -> State# s
writeFloatArray# :: MutByteArr# s -> Int# -> Float# -> State# s -> State# s
writeDoubleArray# :: MutByteArr# s -> Int# -> Double# -> State# s -> State# s
writeStablePtrArray# :: MutByteArr# s -> Int# -> StablePtr# a -> State# s -> State# s
writeInt8Array# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeInt16Array# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeInt32Array# :: MutByteArr# s -> Int# -> Int# -> State# s -> State# s
writeInt64Array# :: MutByteArr# s -> Int# -> Int64# -> State# s -> State# s
writeWord8Array# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeWord16Array# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeWord32Array# :: MutByteArr# s -> Int# -> Word# -> State# s -> State# s
writeWord64Array# :: MutByteArr# s -> Int# -> Word64# -> State# s -> State# s
Addr#
data Addr#

An arbitrary machine address assumed to point outside the garbage-collected heap.

nullAddr# :: Addr#
The null address.
plusAddr# :: Addr# -> Int# -> Addr#
minusAddr# :: Addr# -> Addr# -> Int#
Result is meaningless if two `Addr#`s are so far apart that their difference doesn't fit in an `Int#`.
remAddr# :: Addr# -> Int# -> Int#
Return the remainder when the `Addr#` arg, treated like an `Int#`, is divided by the `Int#` arg.
addr2Int# :: Addr# -> Int#
Coerce directly from address to int. Strongly deprecated.
int2Addr# :: Int# -> Addr#
Coerce directly from int to address. Strongly deprecated.
gtAddr# :: Addr# -> Addr# -> Bool
geAddr# :: Addr# -> Addr# -> Bool
eqAddr# :: Addr# -> Addr# -> Bool
neAddr# :: Addr# -> Addr# -> Bool
ltAddr# :: Addr# -> Addr# -> Bool
leAddr# :: Addr# -> Addr# -> Bool
indexCharOffAddr# :: Addr# -> Int# -> Char#
Reads 8-bit character; offset in bytes.
indexWideCharOffAddr# :: Addr# -> Int# -> Char#
Reads 31-bit character; offset in 4-byte words.
indexIntOffAddr# :: Addr# -> Int# -> Int#
indexWordOffAddr# :: Addr# -> Int# -> Word#
indexAddrOffAddr# :: Addr# -> Int# -> Addr#
indexFloatOffAddr# :: Addr# -> Int# -> Float#
indexDoubleOffAddr# :: Addr# -> Int# -> Double#
indexStablePtrOffAddr# :: Addr# -> Int# -> StablePtr# a
indexInt8OffAddr# :: Addr# -> Int# -> Int#
indexInt16OffAddr# :: Addr# -> Int# -> Int#
indexInt32OffAddr# :: Addr# -> Int# -> Int#
indexInt64OffAddr# :: Addr# -> Int# -> Int64#
indexWord8OffAddr# :: Addr# -> Int# -> Word#
indexWord16OffAddr# :: Addr# -> Int# -> Word#
indexWord32OffAddr# :: Addr# -> Int# -> Word#
indexWord64OffAddr# :: Addr# -> Int# -> Word64#
readCharOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Char##)
Reads 8-bit character; offset in bytes.
readWideCharOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Char##)
Reads 31-bit character; offset in 4-byte words.
readIntOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readWordOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readAddrOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Addr##)
readFloatOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Float##)
readDoubleOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Double##)
readStablePtrOffAddr# :: Addr# -> Int# -> State# s -> (#State# s, StablePtr# a#)
readInt8OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readInt16OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readInt32OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int##)
readInt64OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Int64##)
readWord8OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readWord16OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readWord32OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word##)
readWord64OffAddr# :: Addr# -> Int# -> State# s -> (#State# s, Word64##)
writeCharOffAddr# :: Addr# -> Int# -> Char# -> State# s -> State# s
writeWideCharOffAddr# :: Addr# -> Int# -> Char# -> State# s -> State# s
writeIntOffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeWordOffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeAddrOffAddr# :: Addr# -> Int# -> Addr# -> State# s -> State# s
writeFloatOffAddr# :: Addr# -> Int# -> Float# -> State# s -> State# s
writeDoubleOffAddr# :: Addr# -> Int# -> Double# -> State# s -> State# s
writeStablePtrOffAddr# :: Addr# -> Int# -> StablePtr# a -> State# s -> State# s
writeInt8OffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeInt16OffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeInt32OffAddr# :: Addr# -> Int# -> Int# -> State# s -> State# s
writeInt64OffAddr# :: Addr# -> Int# -> Int64# -> State# s -> State# s
writeWord8OffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeWord16OffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeWord32OffAddr# :: Addr# -> Int# -> Word# -> State# s -> State# s
writeWord64OffAddr# :: Addr# -> Int# -> Word64# -> State# s -> State# s
Mutable variables
Operations on `MutVar#`s.
data MutVar# s a

A `MutVar#` behaves like a single-element mutable array.

newMutVar# :: a -> State# s -> (#State# s, MutVar# s a#)
Create `MutVar#` with specified initial value in specified state thread.
readMutVar# :: MutVar# s a -> State# s -> (#State# s, a#)
Read contents of `MutVar#`. Result is not yet evaluated.
writeMutVar# :: MutVar# s a -> a -> State# s -> State# s
Write contents of `MutVar#`.
sameMutVar# :: MutVar# s a -> MutVar# s a -> Bool
atomicModifyMutVar# :: MutVar# s a -> (a -> b) -> State# s -> (#State# s, c#)
Exceptions
catch# :: (State# RealWorld -> (#State# RealWorld, a#)) -> (b -> State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
raise# :: a -> b
raiseIO# :: a -> State# RealWorld -> (#State# RealWorld, b#)
blockAsyncExceptions# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
unblockAsyncExceptions# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
STM-accessible Mutable Variables
data TVar# s a

atomically# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
retry# :: State# RealWorld -> (#State# RealWorld, a#)
catchRetry# :: (State# RealWorld -> (#State# RealWorld, a#)) -> (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
catchSTM# :: (State# RealWorld -> (#State# RealWorld, a#)) -> (b -> State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, a#)
newTVar# :: a -> State# s -> (#State# s, TVar# s a#)
Create a new `TVar#` holding a specified initial value.
readTVar# :: TVar# s a -> State# s -> (#State# s, a#)
Read contents of `TVar#`. Result is not yet evaluated.
writeTVar# :: TVar# s a -> a -> State# s -> State# s
Write contents of `TVar#`.
sameTVar# :: TVar# s a -> TVar# s a -> Bool
Synchronized Mutable Variables
Operations on `MVar#`s.
data MVar# s a

A shared mutable variable (not the same as a `MutVar#`!). (Note: in a non-concurrent implementation, `(MVar# a)` can be represented by `(MutVar# (Maybe a))`.)

newMVar# :: State# s -> (#State# s, MVar# s a#)
Create new `MVar#`; initially empty.
takeMVar# :: MVar# s a -> State# s -> (#State# s, a#)
If `MVar#` is empty, block until it becomes full. Then remove and return its contents, and set it empty.
tryTakeMVar# :: MVar# s a -> State# s -> (#State# s, Int#, a#)
If `MVar#` is empty, immediately return with integer 0 and value undefined. Otherwise, return with integer 1 and contents of `MVar#`, and set `MVar#` empty.
putMVar# :: MVar# s a -> a -> State# s -> State# s
If `MVar#` is full, block until it becomes empty. Then store value arg as its new contents.
tryPutMVar# :: MVar# s a -> a -> State# s -> (#State# s, Int##)
If `MVar#` is full, immediately return with integer 0. Otherwise, store value arg as `MVar#`'s new contents, and return with integer 1.
sameMVar# :: MVar# s a -> MVar# s a -> Bool
isEmptyMVar# :: MVar# s a -> State# s -> (#State# s, Int##)
Return 1 if `MVar#` is empty; 0 otherwise.
Delay/wait operations
delay# :: Int# -> State# s -> State# s
Sleep specified number of microseconds.
waitRead# :: Int# -> State# s -> State# s
Block until input is available on specified file descriptor.
waitWrite# :: Int# -> State# s -> State# s
Block until output is possible on specified file descriptor.
Concurrency primitives
data State# s

`State#` is the primitive, unlifted type of states. It has one type parameter, thus `State# RealWorld`, or `State# s`, where s is a type variable. The only purpose of the type parameter is to keep different state threads separate. It is represented by nothing at all.

data RealWorld

`RealWorld` is deeply magical. It is primitive, but it is not unlifted (hence `ptrArg`). We never manipulate values of type `RealWorld`; it's only used in the type system, to parameterise `State#`.
Instances

Typeable RealWorld

data ThreadId#

(In a non-concurrent implementation, this can be a singleton type, whose (unique) value is returned by `myThreadId#`. The other operations can be omitted.)

fork# :: a -> State# RealWorld -> (#State# RealWorld, ThreadId##)
forkOn# :: Int# -> a -> State# RealWorld -> (#State# RealWorld, ThreadId##)
killThread# :: ThreadId# -> a -> State# RealWorld -> State# RealWorld
yield# :: State# RealWorld -> State# RealWorld
myThreadId# :: State# RealWorld -> (#State# RealWorld, ThreadId##)
labelThread# :: ThreadId# -> Addr# -> State# RealWorld -> State# RealWorld
isCurrentThreadBound# :: State# RealWorld -> (#State# RealWorld, Int##)
noDuplicate# :: State# RealWorld -> State# RealWorld
Weak pointers
data Weak# b

mkWeak# :: o -> b -> c -> State# RealWorld -> (#State# RealWorld, Weak# b#)
deRefWeak# :: Weak# a -> State# RealWorld -> (#State# RealWorld, Int#, a#)
finalizeWeak# :: Weak# a -> State# RealWorld -> (#State# RealWorld, Int#, State# RealWorld -> (#State# RealWorld, ()#)#)
touch# :: o -> State# RealWorld -> State# RealWorld
Stable pointers and names
data StablePtr# a

data StableName# a

makeStablePtr# :: a -> State# RealWorld -> (#State# RealWorld, StablePtr# a#)
deRefStablePtr# :: StablePtr# a -> State# RealWorld -> (#State# RealWorld, a#)
eqStablePtr# :: StablePtr# a -> StablePtr# a -> Int#
makeStableName# :: a -> State# RealWorld -> (#State# RealWorld, StableName# a#)
eqStableName# :: StableName# a -> StableName# a -> Int#
stableNameToInt# :: StableName# a -> Int#
Unsafe pointer equality
reallyUnsafePtrEquality# :: a -> a -> Int#
Parallelism
par# :: a -> Int#
parGlobal# :: a -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parLocal# :: a -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parAt# :: b -> a -> Int# -> Int# -> Int# -> Int# -> c -> Int#
parAtAbs# :: a -> Int# -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parAtRel# :: a -> Int# -> Int# -> Int# -> Int# -> Int# -> b -> Int#
parAtForNow# :: b -> a -> Int# -> Int# -> Int# -> Int# -> c -> Int#
Tag to enum stuff
Convert back and forth between values of enumerated types and small integers.
dataToTag# :: a -> Int#
tagToEnum# :: Int# -> a
Bytecode operations
Support for the bytecode interpreter and linker.
data BCO#

Primitive bytecode type.

addrToHValue# :: Addr# -> (#a#)
Convert an `Addr#` to a followable type.
mkApUpd0# :: BCO# -> (#a#)
newBCO# :: ByteArr# -> ByteArr# -> Array# a -> ByteArr# -> Int# -> ByteArr# -> State# s -> (#State# s, BCO##)
Etc
Miscellaneous built-ins
seq :: a -> b -> b
Evaluates its first argument to head normal form, and then returns its second argument as the result.
inline :: a -> a

The call `(inline f)` arranges that f is inlined, regardless of its size. More precisely, the call `(inline f)` rewrites to the right-hand side of `f`'s definition. This allows the programmer to control inlining from a particular call site rather than the definition site of the function (c.f. `INLINE` pragmas in User's Guide, Section 7.10.3, "INLINE and NOINLINE pragmas").

This inlining occurs regardless of the argument to the call or the size of `f`'s definition; it is unconditional. The main caveat is that `f`'s definition must be visible to the compiler. That is, `f` must be `let`-bound in the current scope. If no inlining takes place, the `inline` function expands to the identity function in Phase zero; so its use imposes no overhead.

If the function is defined in another module, GHC only exposes its inlining in the interface file if the function is sufficiently small that it might be inlined by the automatic mechanism. There is currently no way to tell GHC to expose arbitrarily-large functions in the interface file. (This shortcoming is something that could be fixed, with some kind of pragma.)

lazy :: a -> a

The `lazy` function restrains strictness analysis a little. The call `(lazy e)` means the same as `e`, but `lazy` has a magical property so far as strictness analysis is concerned: it is lazy in its first argument, even though its semantics is strict. After strictness analysis has run, calls to `lazy` are inlined to be the identity function.

This behaviour is occasionally useful when controlling evaluation order. Notably, `lazy` is used in the library definition of `Control.Parallel.par`:

    par :: a -> b -> b

    par x y = case (par# x) of _ -> lazy y

If `lazy` were not lazy, `par` would look strict in `y` which would defeat the whole purpose of `par`.

Like `seq`, the argument of `lazy` can have an unboxed type.

data Any a

The type constructor `Any` is type to which you can unsafely coerce any lifted type, and back.

- It is lifted, and hence represented by a pointer
- It does not claim to be a data type, and that's important for the code generator, because the code gen may enter a data value but never enters a function value.

It's also used to instantiate un-constrained type variables after type checking. For example

    length Any []

Annoyingly, we sometimes need `Any`s of other kinds, such as `(* -> *)` etc. This is a bit like tuples. We define a couple of useful ones here, and make others up on the fly. If any of these others end up being exported into interface files, we'll get a crash; at least until we add interface-file syntax to support them.

unsafeCoerce# :: a -> b

The function `unsafeCoerce#` allows you to side-step the typechecker entirely. That is, it allows you to coerce any type into any other type. If you use this function, you had better get it right, otherwise segmentation faults await. It is generally used when you want to write a program that you know is well-typed, but where Haskell's type system is not expressive enough to prove that it is well typed.

The argument to `unsafeCoerce#` can have unboxed types, although extremely bad things will happen if you coerce a boxed type to an unboxed type.

Produced by Haddock version 0.8