| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Zydis.Util
Description
This handy module extend Storable typeclasse with default instances for C-like enums/fixed arrays (FFI).
Using StorableExt, we are now able to use deriving via clause on sum types.
data X = A | B | C deriving stock Enum deriving Storable via StorableExt X
This type will be stored as a word32 (C enum FFI).
Synopsis
- newtype StorableExt a = StorableExt {
- unStorableExt :: a
- class Storable a
Documentation
newtype StorableExt a Source #
Wrapper to extend storable default instances.
Constructors
| StorableExt | |
Fields
| |
Instances
| Eq a => Eq (StorableExt a) Source # | |
Defined in Zydis.Util Methods (==) :: StorableExt a -> StorableExt a -> Bool # (/=) :: StorableExt a -> StorableExt a -> Bool # | |
| Show a => Show (StorableExt a) Source # | |
Defined in Zydis.Util Methods showsPrec :: Int -> StorableExt a -> ShowS # show :: StorableExt a -> String # showList :: [StorableExt a] -> ShowS # | |
| Enum a => Storable (StorableExt a) Source # | |
Defined in Zydis.Util Methods sizeOf :: StorableExt a -> Int # alignment :: StorableExt a -> Int # peekElemOff :: Ptr (StorableExt a) -> Int -> IO (StorableExt a) # pokeElemOff :: Ptr (StorableExt a) -> Int -> StorableExt a -> IO () # peekByteOff :: Ptr b -> Int -> IO (StorableExt a) # pokeByteOff :: Ptr b -> Int -> StorableExt a -> IO () # peek :: Ptr (StorableExt a) -> IO (StorableExt a) # poke :: Ptr (StorableExt a) -> StorableExt a -> IO () # | |
The member functions of this class facilitate writing values of primitive types to raw memory (which may have been allocated with the above mentioned routines) and reading values from blocks of raw memory. The class, furthermore, includes support for computing the storage requirements and alignment restrictions of storable types.
Memory addresses are represented as values of type Ptr aa which is an instance of class Storable. The type argument to
Ptr helps provide some valuable type safety in FFI code (you can't
mix pointers of different types without an explicit cast), while
helping the Haskell type system figure out which marshalling method is
needed for a given pointer.
All marshalling between Haskell and a foreign language ultimately
boils down to translating Haskell data structures into the binary
representation of a corresponding data structure of the foreign
language and vice versa. To code this marshalling in Haskell, it is
necessary to manipulate primitive data types stored in unstructured
memory blocks. The class Storable facilitates this manipulation on
all types for which it is instantiated, which are the standard basic
types of Haskell, the fixed size Int types (Int8, Int16,
Int32, Int64), the fixed size Word types (Word8, Word16,
Word32, Word64), StablePtr, all types from Foreign.C.Types,
as well as Ptr.
Minimal complete definition
sizeOf, alignment, (peek | peekElemOff | peekByteOff), (poke | pokeElemOff | pokeByteOff)