Data.GI.Base.BasicTypes

Basic types used in the bindings.

Memory management

data ManagedPtr a

Thin wrapper over ForeignPtr, supporting the extra notion of disowning, that is, not running the finalizers associated with the foreign ptr.

Constructors

ManagedPtr

Fields

• managedForeignPtr :: ForeignPtr a
• managedPtrAllocCallStack :: Maybe CallStack

  CallStack for the call that created the pointer.

• managedPtrIsDisowned :: IORef (Maybe CallStack)

  When disowned, the CallStack for the disowning call.

Instances

Eq (ManagedPtr a)

Two ManagedPtrs are equal if they wrap the same underlying C Ptr.

Methods

(==) :: ManagedPtr a -> ManagedPtr a -> Bool

(/=) :: ManagedPtr a -> ManagedPtr a -> Bool

class Coercible a (ManagedPtr ()) => ManagedPtrNewtype a where

A constraint ensuring that the given type is a newtype over a ManagedPtr.

Minimal complete definition

toManagedPtr

Methods

toManagedPtr :: a -> ManagedPtr a

Instances

Coercible a (ManagedPtr ()) => ManagedPtrNewtype a

A default instance for IsManagedPtr for newtypes over ManagedPtr.

Methods

toManagedPtr :: a -> ManagedPtr a

class ManagedPtrNewtype a => BoxedPtr a where

Pointers to chunks of memory which we know how to copy and release.

Minimal complete definition

boxedPtrCopy, boxedPtrFree

Methods

boxedPtrCopy :: a -> IO a

Make a copy of the given BoxedPtr.

boxedPtrFree :: a -> IO ()

A pointer to a function for freeing the given pointer.

class BoxedPtr a => CallocPtr a where

A ptr to a memory block which we know how to allocate and fill with zero.

Minimal complete definition

boxedPtrCalloc

Methods

boxedPtrCalloc :: IO (Ptr a)

Allocate a zero-initialized block of memory for the given type.

data UnexpectedNullPointerReturn

A common omission in the introspection data is missing (nullable) annotations for return types, when they clearly are nullable. (A common idiom is "Returns: valid value, or %NULL if something went wrong.")

Haskell wrappers will raise this exception if the return value is an unexpected nullPtr.

Constructors

UnexpectedNullPointerReturn

Fields

• nullPtrErrorMsg :: Text

Instances

Show UnexpectedNullPointerReturn

Methods

showsPrec :: Int -> UnexpectedNullPointerReturn -> ShowS

show :: UnexpectedNullPointerReturn -> String

showList :: [UnexpectedNullPointerReturn] -> ShowS

Exception UnexpectedNullPointerReturn

Methods

toException :: UnexpectedNullPointerReturn -> SomeException

fromException :: SomeException -> Maybe UnexpectedNullPointerReturn

displayException :: UnexpectedNullPointerReturn -> String

Basic GLib / GObject types

class HasParentTypes a => TypedObject a where

A wrapped object that has an associated GLib type. This does not necessarily descend from GObject, that constraint is implemented by GObject below.

Minimal complete definition

glibType

Methods

glibType :: IO GType

The GType for this object.

Instances

TypedObject GValue

Find the associated GType for GValue.

Methods

glibType :: IO GType

TypedObject GError

Methods

glibType :: IO GType

TypedObject (GClosure a)

Find the associated GType for the given closure.

Methods

glibType :: IO GType

class (ManagedPtrNewtype a, TypedObject a) => GObject a

A wrapped GObject, or any other type that descends from it.

newtype GType

A newtype for use on the Haskell side.

Constructors

GType

Fields

• gtypeToCGType :: CGType

Instances

Eq GType

Methods

(==) :: GType -> GType -> Bool

(/=) :: GType -> GType -> Bool

Show GType

Methods

showsPrec :: Int -> GType -> ShowS

show :: GType -> String

showList :: [GType] -> ShowS

IsGValue GType

Methods

toGValue :: GType -> IO GValue

fromGValue :: GValue -> IO GType

type CGType = Word64

A type identifier in the GLib type system. This is the low-level type associated with the representation in memory, when using this on the Haskell side use GType below.

gtypeName :: GType -> IO String

Get the name assigned to the given GType.

newtype GVariant

A GVariant. See Data.GI.Base.GVariant for further methods.

Constructors

GVariant (ManagedPtr GVariant)

Instances

IsGVariant GVariant

Methods

toGVariant :: GVariant -> IO GVariant

fromGVariant :: GVariant -> IO (Maybe GVariant)

toGVariantFormatString :: GVariant -> Text

class (ManagedPtrNewtype a, TypedObject a) => GBoxed a

Chunks of memory whose allocation/deallocation info has been registered with the GLib type system.

Instances

GBoxed GValue

GValues are registered as boxed in the GLib type system.

GBoxed GError

GErrors are registered as boxed in the GLib type system.

GBoxed (GClosure a)

GClosures are registered as boxed in the GLib type system.

class TypedObject a => BoxedEnum a

Enums with an associated GType.

class TypedObject a => BoxedFlags a

Flags with an associated GType.

newtype GParamSpec

A GParamSpec. See Data.GI.Base.GParamSpec for further methods.

Constructors

GParamSpec (ManagedPtr GParamSpec)

noGParamSpec :: Maybe GParamSpec

A convenient synonym for Nothing :: Maybe GParamSpec.

data GArray a

A GArray. Marshalling for this type is done in Data.GI.Base.BasicConversions, it is mapped to a list on the Haskell side.

Constructors

GArray (Ptr (GArray a))

data GPtrArray a

A GPtrArray. Marshalling for this type is done in Data.GI.Base.BasicConversions, it is mapped to a list on the Haskell side.

Constructors

GPtrArray (Ptr (GPtrArray a))

data GByteArray

A GByteArray. Marshalling for this type is done in Data.GI.Base.BasicConversions, it is packed to a ByteString on the Haskell side.

Constructors

GByteArray (Ptr GByteArray)

data GHashTable a b

A GHashTable. It is mapped to a Map on the Haskell side.

Constructors

GHashTable (Ptr (GHashTable a b))

data GList a

A GList, mapped to a list on the Haskell side. Marshalling is done in Data.GI.Base.BasicConversions.

Constructors

GList (Ptr (GList a))

g_list_free :: Ptr (GList a) -> IO ()

Free the given GList.

data GSList a

A GSList, mapped to a list on the Haskell side. Marshalling is done in Data.GI.Base.BasicConversions.

Constructors

GSList (Ptr (GSList a))

g_slist_free :: Ptr (GSList a) -> IO ()

Free the given GSList.

class Enum a => IsGFlag a

An enum usable as a flag for a function.

Instances

IsGFlag GParamFlag

newtype PtrWrapped a

Some APIs, such as GHashTable, pass around scalar types wrapped into a pointer. We encode such a type as follows.

Constructors

PtrWrapped

Fields

• unwrapPtr :: Ptr a

type GDestroyNotify a = FunPtr (Ptr a -> IO ())

Destroy the memory associated with a given pointer.