public sealed interface FunctionDescriptor
FunctionDescriptor
is a preview API of the Java platform.
Preview features may be removed in a future release, or upgraded to permanent features of the Java platform.
A function descriptor models the signature of a foreign function. A function descriptor is made up of zero or more
argument layouts, and zero or one return layout. A function descriptor is used to create
downcall method handlesPREVIEW and
upcall stubsPREVIEW.
- Implementation Requirements:
- Implementing classes are immutable, thread-safe and value-based.
- Since:
- 19
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptionappendArgumentLayouts
(MemoryLayoutPREVIEW... addedLayouts) Returns a function descriptor with the given argument layouts appended to the argument layouts of this function descriptor.Returns the argument layouts of this function descriptor (as an unmodifiable list).changeReturnLayout
(MemoryLayoutPREVIEW newReturn) Returns a function descriptor with the provided return layout.Returns a new function descriptor, with no return layout.insertArgumentLayouts
(int index, MemoryLayoutPREVIEW... addedLayouts) Returns a function descriptor with the given argument layouts inserted at the given index, into the argument layout array of this function descriptor.static FunctionDescriptorPREVIEW
of
(MemoryLayoutPREVIEW resLayout, MemoryLayoutPREVIEW... argLayouts) Creates a function descriptor with the given return and argument layouts.static FunctionDescriptorPREVIEW
ofVoid
(MemoryLayoutPREVIEW... argLayouts) Creates a function descriptor with the given argument layouts and no return layout.Returns the return layout (if any) of this function descriptor.Returns the method type consisting of the carrier types of the layouts in this function descriptor.
-
Method Details
-
returnLayout
Optional<MemoryLayoutPREVIEW> returnLayout()Returns the return layout (if any) of this function descriptor.- Returns:
- the return layout (if any) of this function descriptor
-
argumentLayouts
List<MemoryLayoutPREVIEW> argumentLayouts()Returns the argument layouts of this function descriptor (as an unmodifiable list)..- Returns:
- the argument layouts of this function descriptor (as an unmodifiable list)
-
appendArgumentLayouts
Returns a function descriptor with the given argument layouts appended to the argument layouts of this function descriptor.- Parameters:
addedLayouts
- the argument layouts to append.- Returns:
- a new function descriptor, with the provided additional argument layouts.
- Throws:
IllegalArgumentException
- if one of the layouts inaddedLayouts
is a padding layout.
-
insertArgumentLayouts
Returns a function descriptor with the given argument layouts inserted at the given index, into the argument layout array of this function descriptor.- Parameters:
index
- the index at which to insert the argumentsaddedLayouts
- the argument layouts to insert at given index.- Returns:
- a new function descriptor, with the provided additional argument layouts.
- Throws:
IllegalArgumentException
- if one of the layouts inaddedLayouts
is a padding layout.IllegalArgumentException
- ifindex < 0 || index > argumentLayouts().size()
.
-
changeReturnLayout
Returns a function descriptor with the provided return layout.- Parameters:
newReturn
- the new return layout.- Returns:
- a new function descriptor, with the provided return layout.
- Throws:
IllegalArgumentException
- ifnewReturn
is a padding layout.
-
dropReturnLayout
FunctionDescriptorPREVIEW dropReturnLayout()Returns a new function descriptor, with no return layout.- Returns:
- a new function descriptor, with no return layout
-
toMethodType
MethodType toMethodType()Returns the method type consisting of the carrier types of the layouts in this function descriptor.The carrier type of a layout
L
is determined as follows:- If
L
is aValueLayout
PREVIEW the carrier type is determined throughValueLayout.carrier()
PREVIEW. - If
L
is aGroupLayout
PREVIEW or aSequenceLayout
PREVIEW, the carrier type isMemorySegment
PREVIEW.
- API Note:
- A function descriptor cannot, by construction, contain any padding layouts. As such, it is not necessary to specify how padding layout should be mapped to carrier types.
- Returns:
- the method type consisting of the carrier types of the layouts in this function descriptor.
- If
-
of
static FunctionDescriptorPREVIEW of(MemoryLayoutPREVIEW resLayout, MemoryLayoutPREVIEW... argLayouts) Creates a function descriptor with the given return and argument layouts.- Parameters:
resLayout
- the return layout.argLayouts
- the argument layouts.- Returns:
- a new function descriptor with the provided return and argument layouts.
- Throws:
IllegalArgumentException
- ifresLayout
is a padding layout.IllegalArgumentException
- if one of the layouts inargLayouts
is a padding layout.
-
ofVoid
Creates a function descriptor with the given argument layouts and no return layout. This is useful to model functions that return no values.- Parameters:
argLayouts
- the argument layouts.- Returns:
- a new function descriptor with the provided argument layouts.
- Throws:
IllegalArgumentException
- if one of the layouts inargLayouts
is a padding layout.
-
FunctionDescriptor
when preview features are enabled.