ghc-prim-0.1.0.0: GHC primitivesContentsIndex
GHC.Prim
Portabilitynon-portable (GHC extensions)
Stabilityinternal
Maintainercvs-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#, ByteArray##)
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#, ByteArray##)
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#, ByteArray##)
data Word64#
word64ToInteger# :: Word64# -> (#Int#, ByteArray##)
plusInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
minusInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
timesInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
gcdInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
gcdIntegerInt# :: Int# -> ByteArray# -> Int# -> Int#
divExactInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
quotInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
remInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
cmpInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> Int#
cmpIntegerInt# :: Int# -> ByteArray# -> Int# -> Int#
quotRemInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray#, Int#, ByteArray##)
divModInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray#, Int#, ByteArray##)
integer2Int# :: Int# -> ByteArray# -> Int#
integer2Word# :: Int# -> ByteArray# -> Word#
andInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
orInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
xorInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
complementInteger# :: Int# -> ByteArray# -> (#Int#, ByteArray##)
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#, ByteArray##)
decodeDouble_2Int# :: Double# -> (#Int#, Word#, Word#, Int##)
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#, ByteArray##)
decodeFloat_Int# :: Float# -> (#Int#, Int##)
data Array# a
data MutableArray# s a
newArray# :: Int# -> a -> State# s -> (#State# s, MutableArray# s a#)
sameMutableArray# :: MutableArray# s a -> MutableArray# s a -> Bool
readArray# :: MutableArray# s a -> Int# -> State# s -> (#State# s, a#)
writeArray# :: MutableArray# s a -> Int# -> a -> State# s -> State# s
indexArray# :: Array# a -> Int# -> (#a#)
unsafeFreezeArray# :: MutableArray# s a -> State# s -> (#State# s, Array# a#)
unsafeThawArray# :: Array# a -> State# s -> (#State# s, MutableArray# s a#)
data ByteArray#
data MutableByteArray# s
newByteArray# :: Int# -> State# s -> (#State# s, MutableByteArray# s#)
newPinnedByteArray# :: Int# -> State# s -> (#State# s, MutableByteArray# s#)
byteArrayContents# :: ByteArray# -> Addr#
sameMutableByteArray# :: MutableByteArray# s -> MutableByteArray# s -> Bool
unsafeFreezeByteArray# :: MutableByteArray# s -> State# s -> (#State# s, ByteArray##)
sizeofByteArray# :: ByteArray# -> Int#
sizeofMutableByteArray# :: MutableByteArray# s -> Int#
indexCharArray# :: ByteArray# -> Int# -> Char#
indexWideCharArray# :: ByteArray# -> Int# -> Char#
indexIntArray# :: ByteArray# -> Int# -> Int#
indexWordArray# :: ByteArray# -> Int# -> Word#
indexAddrArray# :: ByteArray# -> Int# -> Addr#
indexFloatArray# :: ByteArray# -> Int# -> Float#
indexDoubleArray# :: ByteArray# -> Int# -> Double#
indexStablePtrArray# :: ByteArray# -> Int# -> StablePtr# a
indexInt8Array# :: ByteArray# -> Int# -> Int#
indexInt16Array# :: ByteArray# -> Int# -> Int#
indexInt32Array# :: ByteArray# -> Int# -> Int#
indexInt64Array# :: ByteArray# -> Int# -> Int64#
indexWord8Array# :: ByteArray# -> Int# -> Word#
indexWord16Array# :: ByteArray# -> Int# -> Word#
indexWord32Array# :: ByteArray# -> Int# -> Word#
indexWord64Array# :: ByteArray# -> Int# -> Word64#
readCharArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Char##)
readWideCharArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Char##)
readIntArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readWordArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readAddrArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Addr##)
readFloatArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Float##)
readDoubleArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Double##)
readStablePtrArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, StablePtr# a#)
readInt8Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readInt16Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readInt32Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readInt64Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int64##)
readWord8Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readWord16Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readWord32Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readWord64Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word64##)
writeCharArray# :: MutableByteArray# s -> Int# -> Char# -> State# s -> State# s
writeWideCharArray# :: MutableByteArray# s -> Int# -> Char# -> State# s -> State# s
writeIntArray# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeWordArray# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeAddrArray# :: MutableByteArray# s -> Int# -> Addr# -> State# s -> State# s
writeFloatArray# :: MutableByteArray# s -> Int# -> Float# -> State# s -> State# s
writeDoubleArray# :: MutableByteArray# s -> Int# -> Double# -> State# s -> State# s
writeStablePtrArray# :: MutableByteArray# s -> Int# -> StablePtr# a -> State# s -> State# s
writeInt8Array# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeInt16Array# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeInt32Array# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeInt64Array# :: MutableByteArray# s -> Int# -> Int64# -> State# s -> State# s
writeWord8Array# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeWord16Array# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeWord32Array# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeWord64Array# :: MutableByteArray# 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#)
asyncExceptionsBlocked# :: State# RealWorld -> (#State# RealWorld, Int##)
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#)
check# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, ()#)
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
threadStatus# :: ThreadId# -> State# RealWorld -> (#State# RealWorld, Int##)
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# :: ByteArray# -> ByteArray# -> Array# a -> Int# -> ByteArray# -> State# s -> (#State# s, BCO##)
unpackClosure# :: a -> (#Addr#, Array# b, ByteArray##)
getApStackVal# :: a -> Int# -> (#Int#, b#)
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 ByteArray# -> Int# -> Int#; otherwise it has type ByteArray# -> 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#, ByteArray##)
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#, ByteArray##)
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#, ByteArray##)
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#, ByteArray##)
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 ByteArray# 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# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
minusInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
timesInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
gcdInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
Greatest common divisor.
gcdIntegerInt# :: Int# -> ByteArray# -> Int# -> Int#
Greatest common divisor, where second argument is an ordinary Int#.
divExactInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
Divisor is guaranteed to be a factor of dividend.
quotInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
Rounds towards zero.
remInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
Satisfies plusInteger# (timesInteger# (quotInteger# x y) y) (remInteger# x y) == x.
cmpInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> Int#
Returns -1,0,1 according as first argument is less than, equal to, or greater than second argument.
cmpIntegerInt# :: Int# -> ByteArray# -> 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# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray#, Int#, ByteArray##)
Compute quot and rem simulaneously.
divModInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray#, Int#, ByteArray##)
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# -> ByteArray# -> Int#
integer2Word# :: Int# -> ByteArray# -> Word#
andInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
orInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
xorInteger# :: Int# -> ByteArray# -> Int# -> ByteArray# -> (#Int#, ByteArray##)
complementInteger# :: Int# -> ByteArray# -> (#Int#, ByteArray##)
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#
Truncates a Double. Results are undefined if the truncation if truncation yields a value outside the range of 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#, ByteArray##)
Convert to arbitrary-precision integer. First Int# in result is the exponent; second Int# and ByteArray# represent an Integer# holding the mantissa.
decodeDouble_2Int# :: Double# -> (#Int#, Word#, Word#, Int##)
Convert to arbitrary-precision integer. First component of the result is -1 or 1, indicating the sign of the mantissa. The next two are the high and low 32 bits of the mantissa respectively, and the last is the exponent.
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#
Truncates a Float. Results are undefined if the truncation if truncation yields a value outside the range of 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#, ByteArray##)
Convert to arbitrary-precision integer. First Int# in result is the exponent; second Int# and ByteArray# represent an Integer# holding the mantissa.
decodeFloat_Int# :: Float# -> (#Int#, Int##)
Convert to arbitrary-precision integer. First Int# in result is the mantissa; second is the exponent.
Arrays
Operations on Array#.
data Array# a
data MutableArray# s a
newArray# :: Int# -> a -> State# s -> (#State# s, MutableArray# 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# :: MutableArray# s a -> MutableArray# s a -> Bool
readArray# :: MutableArray# s a -> Int# -> State# s -> (#State# s, a#)
Read from specified index of mutable array. Result is not yet evaluated.
writeArray# :: MutableArray# 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# :: MutableArray# s a -> State# s -> (#State# s, Array# a#)
Make a mutable array immutable, without copying.
unsafeThawArray# :: Array# a -> State# s -> (#State# s, MutableArray# 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 ByteArray#
data MutableByteArray# s
newByteArray# :: Int# -> State# s -> (#State# s, MutableByteArray# s#)
Create a new mutable byte array of specified size (in bytes), in the specified state thread.
newPinnedByteArray# :: Int# -> State# s -> (#State# s, MutableByteArray# s#)
Create a mutable byte array that the GC guarantees not to move.
byteArrayContents# :: ByteArray# -> Addr#
Intended for use with pinned arrays; otherwise very unsafe!
sameMutableByteArray# :: MutableByteArray# s -> MutableByteArray# s -> Bool
unsafeFreezeByteArray# :: MutableByteArray# s -> State# s -> (#State# s, ByteArray##)
Make a mutable byte array immutable, without copying.
sizeofByteArray# :: ByteArray# -> Int#
sizeofMutableByteArray# :: MutableByteArray# s -> Int#
indexCharArray# :: ByteArray# -> Int# -> Char#
Read 8-bit character; offset in bytes.
indexWideCharArray# :: ByteArray# -> Int# -> Char#
Read 31-bit character; offset in 4-byte words.
indexIntArray# :: ByteArray# -> Int# -> Int#
indexWordArray# :: ByteArray# -> Int# -> Word#
indexAddrArray# :: ByteArray# -> Int# -> Addr#
indexFloatArray# :: ByteArray# -> Int# -> Float#
indexDoubleArray# :: ByteArray# -> Int# -> Double#
indexStablePtrArray# :: ByteArray# -> Int# -> StablePtr# a
indexInt8Array# :: ByteArray# -> Int# -> Int#
indexInt16Array# :: ByteArray# -> Int# -> Int#
indexInt32Array# :: ByteArray# -> Int# -> Int#
indexInt64Array# :: ByteArray# -> Int# -> Int64#
indexWord8Array# :: ByteArray# -> Int# -> Word#
indexWord16Array# :: ByteArray# -> Int# -> Word#
indexWord32Array# :: ByteArray# -> Int# -> Word#
indexWord64Array# :: ByteArray# -> Int# -> Word64#
readCharArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Char##)
Read 8-bit character; offset in bytes.
readWideCharArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Char##)
Read 31-bit character; offset in 4-byte words.
readIntArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readWordArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readAddrArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Addr##)
readFloatArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Float##)
readDoubleArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Double##)
readStablePtrArray# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, StablePtr# a#)
readInt8Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readInt16Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readInt32Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int##)
readInt64Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Int64##)
readWord8Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readWord16Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readWord32Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word##)
readWord64Array# :: MutableByteArray# s -> Int# -> State# s -> (#State# s, Word64##)
writeCharArray# :: MutableByteArray# s -> Int# -> Char# -> State# s -> State# s
Write 8-bit character; offset in bytes.
writeWideCharArray# :: MutableByteArray# s -> Int# -> Char# -> State# s -> State# s
Write 31-bit character; offset in 4-byte words.
writeIntArray# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeWordArray# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeAddrArray# :: MutableByteArray# s -> Int# -> Addr# -> State# s -> State# s
writeFloatArray# :: MutableByteArray# s -> Int# -> Float# -> State# s -> State# s
writeDoubleArray# :: MutableByteArray# s -> Int# -> Double# -> State# s -> State# s
writeStablePtrArray# :: MutableByteArray# s -> Int# -> StablePtr# a -> State# s -> State# s
writeInt8Array# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeInt16Array# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeInt32Array# :: MutableByteArray# s -> Int# -> Int# -> State# s -> State# s
writeInt64Array# :: MutableByteArray# s -> Int# -> Int64# -> State# s -> State# s
writeWord8Array# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeWord16Array# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeWord32Array# :: MutableByteArray# s -> Int# -> Word# -> State# s -> State# s
writeWord64Array# :: MutableByteArray# 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#)
asyncExceptionsBlocked# :: State# RealWorld -> (#State# RealWorld, Int##)
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#)
check# :: (State# RealWorld -> (#State# RealWorld, a#)) -> State# RealWorld -> (#State# RealWorld, ()#)
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#.
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
threadStatus# :: ThreadId# -> State# RealWorld -> (#State# RealWorld, Int##)
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# :: ByteArray# -> ByteArray# -> Array# a -> Int# -> ByteArray# -> State# s -> (#State# s, BCO##)
unpackClosure# :: a -> (#Addr#, Array# b, ByteArray##)
getApStackVal# :: a -> Int# -> (#Int#, b#)
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 Anys 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 following uses of unsafeCoerce# are supposed to work (i.e. not lead to spurious compile-time or run-time crashes):

  • Casting any lifted type to Any
  • Casting Any back to the real type
  • Casting an unboxed type to another unboxed type of the same size (but not coercions between floating-point and integral types)
  • Casting between two types that have the same runtime representation. One case is when the two types differ only in "phantom" type parameters, for example Ptr Int to Ptr Float, or [Int] to [Float] when the list is known to be empty. Also, a newtype of a type T has the same representation at runtime as T.

Other uses of unsafeCoerce# are undefined. In particular, you should not use unsafeCoerce# to cast a T to an algebraic data type D, unless T is also an algebraic data type. For example, do not cast Int->Int to Bool, even if you later cast that Bool back to Int->Int before applying it. The reasons have to do with GHC's internal representation details (for the congnoscenti, data values can be entered but function closures cannot). If you want a safe type to cast things to, use Any, which is not an algebraic data type.

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