Interface MemoryLayout.PathElement
- Enclosing interface:
MemoryLayout
public static sealed interface MemoryLayout.PathElement
An element in a layout path.
There are three kinds of path elements:
- group path elements, used to select a member layout within a
GroupLayout, either by name or by index; - sequence path elements, used to select one or more
sequence element layouts within a
SequenceLayout; and - dereference path elements, used to dereference an address layout as its target layout.
- Implementation Requirements:
- Implementations of this interface are immutable, thread-safe and value-based.
- Since:
- 22
-
Method Summary
Static MethodsModifier and TypeMethodDescriptionstatic MemoryLayout.PathElementReturns a path element that selects the target layout of an address layout (where set).static MemoryLayout.PathElementgroupElement(long index) Returns a path element that selects a member layout with the given index in a group layout.static MemoryLayout.PathElementgroupElement(String name) Returns a path element which selects a member layout with the given name in a group layout.static MemoryLayout.PathElementReturns an open path element that selects an unspecified element layout in a sequence layout.static MemoryLayout.PathElementsequenceElement(long index) Returns a path element which selects the element layout at the specified index in a sequence layout.static MemoryLayout.PathElementsequenceElement(long start, long step) Returns an open path element that selects the element layout in a range of positions in a sequence layout.
-
Method Details
-
groupElement
Returns a path element which selects a member layout with the given name in a group layout.- Implementation Requirements:
- in case multiple group elements with a matching name exist, the path
element returned by this method will select the first one; that is,
the group element with the lowest offset from the current path is
selected. In such cases, using
groupElement(long)might be preferable. - Parameters:
name- the name of the member layout to be selected- Returns:
- a path element which selects a member layout with the given name in a group layout
-
groupElement
Returns a path element that selects a member layout with the given index in a group layout.- Parameters:
index- the index of the member layout element to be selected- Returns:
- a path element that selects a member layout with the given index in a group layout
- Throws:
IllegalArgumentException- ifindex < 0
-
sequenceElement
Returns a path element which selects the element layout at the specified index in a sequence layout.- Parameters:
index- the index of the sequence element to be selected- Returns:
- a path element which selects the element layout at the specified index in a sequence layout
- Throws:
IllegalArgumentException- ifindex < 0
-
sequenceElement
Returns an open path element that selects the element layout in a range of positions in a sequence layout. The range is expressed as a pair of starting index (inclusive)Sand step factor (which can also be negative)F.The exact sequence element selected by this layout is expressed as an index
I. IfCis the sequence element count, it follows that0 <= I < B, whereBis computed as follows:- if
F > 0, thenB = ceilDiv(C - S, F) - if
F < 0, thenB = ceilDiv(S + 1, -F)
B.- Parameters:
start- the index of the first sequence element to be selectedstep- the step factor at which subsequence sequence elements are to be selected- Returns:
- a path element that selects the sequence element layout with the given index.
- Throws:
IllegalArgumentException- ifstart < 0, orstep == 0
- if
-
sequenceElement
Returns an open path element that selects an unspecified element layout in a sequence layout.The exact sequence element selected by this layout is expressed as an index
I. IfCis the sequence element count, it follows that0 <= I < C. That is,Cis the size of the returned open path element.- Returns:
- an open path element that selects an unspecified element layout in a sequence layout
-
dereferenceElement
Returns a path element that selects the target layout of an address layout (where set).- Returns:
- a path element that selects the target layout of an address layout (where set)
-