visit_type.h File Reference

Visitor pattern for Iceberg types Adapted from Apache Arrow https://github.com/apache/arrow/blob/main/cpp/src/arrow/visit_type_inline.h. More...

#include <utility>
#include "iceberg/result.h"
#include "iceberg/type.h"
#include "iceberg/util/checked_cast.h"
#include "iceberg/util/visitor_generate.h"

Go to the source code of this file.

Macros
#define	TYPE_VISIT_INLINE(TYPE_CLASS)
#define	TYPE_VISIT_INLINE(TYPE_CLASS)
#define	TYPE_ID_VISIT_INLINE(TYPE_CLASS)
#define	SCHEMA_VISIT_ACTION(TYPE_CLASS)

Functions
template<typename VISITOR , typename... ARGS>
Status	iceberg::VisitTypeInline (const Type &type, VISITOR *visitor, ARGS &&... args)
	Calls visitor with the corresponding concrete type class.
template<typename VISITOR , typename... ARGS>
auto	iceberg::VisitType (const Type &type, VISITOR &&visitor, ARGS &&... args) -> decltype(std::forward< VISITOR >(visitor)(type, args...))
	Call visitor with the corresponding concrete type class.
template<typename VISITOR , typename... ARGS>
Status	iceberg::VisitTypeIdInline (TypeId id, VISITOR *visitor, ARGS &&... args)
	Calls visitor with a nullptr of the corresponding concrete type class.
template<typename VISITOR , typename... ARGS>
auto	iceberg::VisitTypeCategory (const Type &type, VISITOR *visitor, ARGS &&... args)
	Visit a type using a categorical visitor pattern.

Detailed Description

Visitor pattern for Iceberg types Adapted from Apache Arrow https://github.com/apache/arrow/blob/main/cpp/src/arrow/visit_type_inline.h.

Macro Definition Documentation

SCHEMA_VISIT_ACTION

#define SCHEMA_VISIT_ACTION

(

TYPE_CLASS

)

Value:

  return visitor->Visit##TYPE_CLASS(                         \
      internal::checked_cast<const TYPE_CLASS##Type&>(type), \
      std::forward<ARGS>(args)...);

TYPE_ID_VISIT_INLINE

#define TYPE_ID_VISIT_INLINE

(

TYPE_CLASS

)

Value:

  case TYPE_CLASS##Type::kTypeId: {                                   \
    const TYPE_CLASS##Type* concrete_ptr = nullptr;                   \
    return visitor->Visit(concrete_ptr, std::forward<ARGS>(args)...); \
  }

TYPE_VISIT_INLINE [1/2]

#define TYPE_VISIT_INLINE

(

TYPE_CLASS

)

Value:

  case TYPE_CLASS##Type::kTypeId:                                       \
    return visitor->Visit(                                              \
        iceberg::internal::checked_cast<const TYPE_CLASS##Type&>(type), \
        std::forward<ARGS>(args)...);

TYPE_VISIT_INLINE [2/2]

#define TYPE_VISIT_INLINE

(

TYPE_CLASS

)

Value:

  case TYPE_CLASS##Type::kTypeId:                              \
    return std::forward<VISITOR>(visitor)(                     \
        internal::checked_cast<const TYPE_CLASS##Type&>(type), \
        std::forward<ARGS>(args)...);

Function Documentation

VisitType()

template<typename VISITOR , typename... ARGS>

auto iceberg::VisitType ( const Type &  type, VISITOR &&  visitor, ARGS &&...  args  ) -> decltype(std::forward<VISITOR>(visitor)(type, args...))

inline

Call visitor with the corresponding concrete type class.

Template Parameters

ARGS	Additional arguments, if any, will be passed to the Visit function after the type argument

Unlike VisitTypeInline which calls visitor.Visit, here visitor itself is called. visitor must support a const Type& argument as a fallback, in addition to concrete type classes.

The intent is for this to be called on a generic lambda that may internally use if constexpr or similar constructs.

VisitTypeCategory()

template<typename VISITOR , typename... ARGS>

auto iceberg::VisitTypeCategory ( const Type &  type, VISITOR *  visitor, ARGS &&...  args  )

inline

Visit a type using a categorical visitor pattern.

This function provides a simplified visitor interface that groups Iceberg types into four categories based on their structural properties:

• Struct types: Complex types with named fields (StructType)
• List types: Sequential container types (ListType)
• Map types: Key-value container types (MapType)
• Primitive types: All leaf types without nested structure (14 primitive types)

This grouping is useful for algorithms that need to distinguish between container types and leaf types, but don't require separate handling for each primitive type variant (e.g., Int vs Long vs String).

Template Parameters

VISITOR	Visitor class that must implement four Visit methods: VisitStruct(const StructType&, ARGS...) for struct types VisitList(const ListType&, ARGS...) for list types VisitMap(const MapType&, ARGS...) for map types VisitPrimitive(const PrimitiveType&, ARGS...) for all primitive types
ARGS	Additional argument types forwarded to Visit methods

Parameters

type	The type to visit
visitor	Pointer to the visitor instance
args	Additional arguments forwarded to the Visit methods

Returns

The return value from the invoked Visit method

VisitTypeIdInline()

template<typename VISITOR , typename... ARGS>

Status iceberg::VisitTypeIdInline ( TypeId  id, VISITOR *  visitor, ARGS &&...  args  )

inline

Calls visitor with a nullptr of the corresponding concrete type class.

Template Parameters

VISITOR	Visitor type that implements Visit() for all Iceberg types.
ARGS	Additional arguments, if any, will be passed to the Visit function after the type argument

Returns

Status

VisitTypeInline()

template<typename VISITOR , typename... ARGS>

Status iceberg::VisitTypeInline ( const Type &  type, VISITOR *  visitor, ARGS &&...  args  )

inline

Calls visitor with the corresponding concrete type class.

Template Parameters

VISITOR	Visitor type that implements Visit() for all Iceberg types.
ARGS	Additional arguments, if any, will be passed to the Visit function after the type argument

Returns

Status

A visitor is a type that implements specialized logic for each Iceberg type. Example usage:

class ExampleVisitor {
  Status Visit(const IntType& type) { ... }
  Status Visit(const LongType& type) { ... }
  ...
}
ExampleVisitor visitor;
VisitTypeInline(some_type, &visitor);