Scalars¶

struct Scalar : public arrow::util::EqualityComparable<Scalar>¶

Base class for scalar values.

A Scalar represents a single value with a specific DataType. Scalars are useful for passing single value inputs to compute functions, or for representing individual array elements (with a non-trivial wrapping cost, though).

Subclassed by arrow::BaseBinaryScalar, arrow::BaseListScalar, arrow::Decimal128Scalar, arrow::Decimal256Scalar, arrow::DictionaryScalar, arrow::ExtensionScalar, arrow::NullScalar, arrow::StructScalar, arrow::UnionScalar, arrow::internal::PrimitiveScalarBase

Public Members

std::shared_ptr<DataType> type¶: The type of the scalar value.

bool is_valid = false¶: Whether the value is valid (not null) or not.

Factory functions¶

std::shared_ptr<Scalar> arrow::MakeNullScalar(std::shared_ptr<DataType> type)¶: Scalar factory for null scalars.

template<typename Value> Result<std::shared_ptr<Scalar>> arrow::MakeScalar(std::shared_ptr<DataType> type, Value &&value)¶: Scalar factory for non-null scalars.

template<typename Value, typename Traits = CTypeTraits<typename std::decay<Value>::type>, typename ScalarType = typename Traits::ScalarType, typename Enable = decltype(ScalarType(std::declval<Value>(), Traits::type_singleton()))> std::shared_ptr<Scalar> arrow::MakeScalar(Value value)¶

Type-inferring scalar factory for non-null scalars.

Construct a Scalar instance with a DataType determined by the input C++ type. (for example Int8Scalar for a int8_t input). Only non-parametric primitive types and String are supported.

std::shared_ptr<Scalar> arrow::MakeScalar(std::string value)¶

Concrete scalar subclasses¶

struct NullScalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

A scalar value for NullType. Never valid.

Public Types

using TypeClass = NullType ¶

Public Functions

NullScalar()¶

struct BooleanScalar : public arrow::internal::PrimitiveScalar<BooleanType, bool>¶

#include <arrow/scalar.h>

Public Types

using Base = internal::PrimitiveScalar<BooleanType, bool>¶

Public Functions

BooleanScalar(bool value)¶

BooleanScalar()¶

template<typename T> struct NumericScalar : public arrow::internal::PrimitiveScalar<T>¶

#include <arrow/scalar.h>

Public Types

template<> using Base = typename internal::PrimitiveScalar<T>¶

template<> using TypeClass = typename Base::TypeClass¶

template<> using ValueType = typename Base::ValueType¶

Public Functions

NumericScalar(ValueType value)¶

NumericScalar()¶

struct BaseBinaryScalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Subclassed by arrow::BinaryScalar, arrow::LargeBinaryScalar

Public Types

using ValueType = std::shared_ptr<Buffer>¶

Public Functions

Scalar(std::shared_ptr<DataType> type)¶

Scalar(std::shared_ptr<DataType> type, bool is_valid)¶

Public Members

std::shared_ptr<Buffer> value¶

struct BinaryScalar : public arrow::BaseBinaryScalar ¶

#include <arrow/scalar.h>

Subclassed by arrow::FixedSizeBinaryScalar, arrow::StringScalar

Public Types

using TypeClass = BinaryType ¶

Public Functions

BinaryScalar(std::shared_ptr<Buffer> value, std::shared_ptr<DataType> type)¶

BinaryScalar(std::shared_ptr<Buffer> value)¶

BinaryScalar()¶

BaseBinaryScalar(std::shared_ptr<Buffer> value, std::shared_ptr<DataType> type)¶

struct StringScalar : public arrow::BinaryScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = StringType ¶

Public Functions

StringScalar(std::shared_ptr<Buffer> value)¶

StringScalar(std::string s)¶

StringScalar()¶

BinaryScalar(std::shared_ptr<Buffer> value, std::shared_ptr<DataType> type)

BinaryScalar(std::shared_ptr<Buffer> value)

BinaryScalar()

struct LargeBinaryScalar : public arrow::BaseBinaryScalar ¶

#include <arrow/scalar.h>

Subclassed by arrow::LargeStringScalar

Public Types

using TypeClass = LargeBinaryType¶

Public Functions

LargeBinaryScalar(std::shared_ptr<Buffer> value, std::shared_ptr<DataType> type)¶

LargeBinaryScalar(std::shared_ptr<Buffer> value)¶

LargeBinaryScalar()¶

BaseBinaryScalar(std::shared_ptr<Buffer> value, std::shared_ptr<DataType> type)

struct LargeStringScalar : public arrow::LargeBinaryScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = LargeStringType¶

Public Functions

LargeStringScalar(std::shared_ptr<Buffer> value)¶

LargeStringScalar(std::string s)¶

LargeStringScalar()¶

LargeBinaryScalar(std::shared_ptr<Buffer> value, std::shared_ptr<DataType> type)

LargeBinaryScalar(std::shared_ptr<Buffer> value)

LargeBinaryScalar()

struct FixedSizeBinaryScalar : public arrow::BinaryScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = FixedSizeBinaryType ¶

Public Functions

FixedSizeBinaryScalar(std::shared_ptr<Buffer> value, std::shared_ptr<DataType> type)¶

FixedSizeBinaryScalar(std::shared_ptr<DataType> type)¶

template<typename T> struct TemporalScalar : public arrow::internal::PrimitiveScalar<T>¶

#include <arrow/scalar.h>

Subclassed by arrow::DateScalar< Date64Type >, arrow::DateScalar< Date32Type >, arrow::IntervalScalar< MonthIntervalType >, arrow::IntervalScalar< DayTimeIntervalType >, arrow::TimeScalar< Time64Type >, arrow::TimeScalar< Time32Type >, arrow::DateScalar< T >, arrow::IntervalScalar< T >, arrow::TimeScalar< T >

Public Types

template<> using ValueType = typename TemporalScalar::ValueType¶

Public Functions

TemporalScalar(ValueType value, std::shared_ptr<DataType> type)¶

template<typename T> struct DateScalar : public arrow::TemporalScalar<T>¶

#include <arrow/scalar.h>

Public Types

template<> using ValueType = typename TemporalScalar::ValueType¶

Public Functions

DateScalar(ValueType value)¶

DateScalar()¶

template<typename T> struct IntervalScalar : public arrow::TemporalScalar<T>¶

#include <arrow/scalar.h>

Public Types

template<> using ValueType = typename TemporalScalar::ValueType¶

Public Functions

IntervalScalar(ValueType value)¶

IntervalScalar()¶

struct Decimal128Scalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = Decimal128Type ¶

using ValueType = Decimal128 ¶

Public Functions

Decimal128Scalar(Decimal128 value, std::shared_ptr<DataType> type)¶

Scalar(std::shared_ptr<DataType> type)

Scalar(std::shared_ptr<DataType> type, bool is_valid)

Public Members

Decimal128 value¶

struct Decimal256Scalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = Decimal256Type¶

using ValueType = Decimal256¶

Public Functions

Decimal256Scalar(Decimal256 value, std::shared_ptr<DataType> type)¶

Scalar(std::shared_ptr<DataType> type)

Scalar(std::shared_ptr<DataType> type, bool is_valid)

Public Members

Decimal256 value¶

struct BaseListScalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Subclassed by arrow::FixedSizeListScalar, arrow::LargeListScalar, arrow::ListScalar, arrow::MapScalar

Public Types

using ValueType = std::shared_ptr<Array>¶

Public Functions

BaseListScalar(std::shared_ptr<Array> value, std::shared_ptr<DataType> type)¶

Scalar(std::shared_ptr<DataType> type)

Scalar(std::shared_ptr<DataType> type, bool is_valid)

Public Members

std::shared_ptr<Array> value¶

struct ListScalar : public arrow::BaseListScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = ListType ¶

Public Functions

ListScalar(std::shared_ptr<Array> value)¶

BaseListScalar(std::shared_ptr<Array> value, std::shared_ptr<DataType> type)

struct LargeListScalar : public arrow::BaseListScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = LargeListType¶

Public Functions

LargeListScalar(std::shared_ptr<Array> value)¶

BaseListScalar(std::shared_ptr<Array> value, std::shared_ptr<DataType> type)

struct MapScalar : public arrow::BaseListScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = MapType ¶

Public Functions

MapScalar(std::shared_ptr<Array> value)¶

BaseListScalar(std::shared_ptr<Array> value, std::shared_ptr<DataType> type)

struct FixedSizeListScalar : public arrow::BaseListScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = FixedSizeListType¶

Public Functions

FixedSizeListScalar(std::shared_ptr<Array> value, std::shared_ptr<DataType> type)¶

FixedSizeListScalar(std::shared_ptr<Array> value)¶

BaseListScalar(std::shared_ptr<Array> value, std::shared_ptr<DataType> type)

struct StructScalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = StructType ¶

using ValueType = std::vector<std::shared_ptr<Scalar>>¶

Public Functions

Result<std::shared_ptr<Scalar>> field(FieldRef ref) const¶

StructScalar(ValueType value, std::shared_ptr<DataType> type)¶

StructScalar(std::shared_ptr<DataType> type)¶

Public Members

ScalarVector value¶

Public Static Functions

static Result<std::shared_ptr<StructScalar>> Make(ValueType value, std::vector<std::string> field_names)¶

struct UnionScalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Subclassed by arrow::DenseUnionScalar, arrow::SparseUnionScalar

Public Types

using ValueType = std::shared_ptr<Scalar>¶

Public Functions

UnionScalar(ValueType value, std::shared_ptr<DataType> type)¶

Scalar(std::shared_ptr<DataType> type)

Scalar(std::shared_ptr<DataType> type, bool is_valid)

Public Members

ValueType value¶

struct SparseUnionScalar : public arrow::UnionScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = SparseUnionType¶

Public Functions

UnionScalar(ValueType value, std::shared_ptr<DataType> type)

struct DenseUnionScalar : public arrow::UnionScalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = DenseUnionType¶

Public Functions

UnionScalar(ValueType value, std::shared_ptr<DataType> type)

struct DictionaryScalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = DictionaryType ¶

Public Functions

DictionaryScalar(std::shared_ptr<DataType> type)¶

DictionaryScalar(ValueType value, std::shared_ptr<DataType> type, bool is_valid = true)¶

Result<std::shared_ptr<Scalar>> GetEncodedValue() const¶

Public Members

struct arrow::DictionaryScalar::ValueType value¶

Public Static Functions

static std::shared_ptr<DictionaryScalar> Make(std::shared_ptr<Scalar> index, std::shared_ptr<Array> dict)¶

struct ValueType¶

#include <arrow/scalar.h>

Public Members

std::shared_ptr<Scalar> index¶

std::shared_ptr<Array> dictionary¶

struct ExtensionScalar : public arrow::Scalar ¶

#include <arrow/scalar.h>

Public Types

using TypeClass = ExtensionType¶

Public Functions

Scalar(std::shared_ptr<DataType> type)

Scalar(std::shared_ptr<DataType> type, bool is_valid)

Arrays Array Builders