Class StructuralVisitorObj

• Defined in File structural_visit.h

Inheritance Relationships

Base Type

• public tvm::ffi::Object (Class Object)

Derived Type

• public tvm::ffi::details::StructuralWalkCallbackVisitorObj< order, Dispatch >

Class Documentation

class StructuralVisitorObj : public tvm::ffi::Object

Object node of a structural visitor.

A structural visitor is an active traversal context. It carries the dispatch table used to visit each object and the current def-region state used by structural equality/hash semantics. The visitor is ref-counted so it can cross FFI boundaries, but one underlying visitor object should not be shared by overlapping top-level traversals.

Subclassed by tvm::ffi::details::StructuralWalkCallbackVisitorObj< order, Dispatch >

Public Functions

inline Optional<VisitInterrupt> Visit(AnyView value)

Visit a value, dispatching through this visitor’s vtable.

Parameters:

value – The value to visit.

Returns:

std::nullopt to continue traversal, or a VisitInterrupt to halt the entire visit.

inline Expected<Optional<VisitInterrupt>> VisitExpected(AnyView value) noexcept

Visit a value, propagating error through expected return.

Parameters:

value – The value to visit.

Returns:

Expected interrupt state. An error means traversal failed.

inline TVMFFIDefRegionKind def_region_kind() const

Return the current def-region context.

Returns:

The active def-region kind.

template<typename Callback>
inline auto WithDefRegionKind(TVMFFIDefRegionKind kind, Callback &&callback)

Temporarily switch the def-region context while invoking callback.

Parameters:

• kind – The def-region kind to set during the callback.

• callback – A nullary callable that performs recursive visiting.

Returns:

The value returned by callback.

inline Expected<Optional<VisitInterrupt>> DefaultVisitExpected(AnyView value) noexcept

Visit using the structural visit behavior registered by kStructuralVisit for each type, or reflected structural fields when no custom behavior is registered.

Parameters:

value – The value to visit.

Returns:

Expected interrupt state. An error means traversal failed.

Protected Functions

inline explicit StructuralVisitorObj(const StructuralVisitorVTable *vtable)

Construct a structural visitor from an immutable dispatch vtable.

Parameters:

vtable – The non-null dispatch table for this visitor. It must outlive this object.

Protected Attributes

const StructuralVisitorVTable *vtable_ = nullptr

Required ABI dispatch table. StructuralVisitorVTable It must never be null on a constructed visitor.

TVMFFIDefRegionKind def_region_mode_ = kTVMFFIDefRegionKindNone

Current def-region context for structural equality/hash semantics.

This is shared mutable traversal state. Be careful when mutating it through multiple references to the same visitor object. Use WithDefRegionKind to scope temporary changes.