Dictionary Classes

group dictionary_classes

Typedefs

using dictionary32 = dictionary_wrapper<int32_t>

32-bit integer indexed dictionary wrapper

Functions

template<typename Integer>
inline bool operator==(dictionary_wrapper<Integer> const &lhs, dictionary_wrapper<Integer> const &rhs)

Wqual to operator for dictionary_wrapper.

Template Parameters:

Integer – Index type

Parameters:

• lhs – Left hand side of comparison

• rhs – Right hand side of comparison

Returns:

Returns true if lhs is equal to rhs, false otherwise

template<typename Integer>
inline bool operator!=(dictionary_wrapper<Integer> const &lhs, dictionary_wrapper<Integer> const &rhs)

Not equal to operator for dictionary_wrapper.

Template Parameters:

Integer – Index type

Parameters:

• lhs – Left hand side of comparison

• rhs – Right hand side of comparison

Returns:

Returns true if lhs is not equal to rhs, false otherwise

template<typename Integer>
inline bool operator<=(dictionary_wrapper<Integer> const &lhs, dictionary_wrapper<Integer> const &rhs)

Less than or equal to operator for dictionary_wrapper.

Template Parameters:

Integer – Index type

Parameters:

• lhs – Left hand side of comparison

• rhs – Right hand side of comparison

Returns:

Returns true if lhs is less than or equal to rhs, false otherwise

template<typename Integer>
inline bool operator>=(dictionary_wrapper<Integer> const &lhs, dictionary_wrapper<Integer> const &rhs)

Greater than or equal to operator for dictionary_wrapper.

Template Parameters:

Integer – Index type

Parameters:

• lhs – Left hand side of comparison

• rhs – Right hand side of comparison

Returns:

Returns true if lhs is greater than or equal to rhs, false otherwise

template<typename Integer>
inline constexpr bool operator<(dictionary_wrapper<Integer> const &lhs, dictionary_wrapper<Integer> const &rhs)

Less than operator for dictionary_wrapper.

Template Parameters:

Integer – Index type

Parameters:

• lhs – Left hand side of comparison

• rhs – Right hand side of comparison

Returns:

Returns true if lhs is less than rhs, false otherwise

template<typename Integer>
inline bool operator>(dictionary_wrapper<Integer> const &lhs, dictionary_wrapper<Integer> const &rhs)

Greater than operator for dictionary_wrapper.

Template Parameters:

Integer – Index type

Parameters:

• lhs – Left hand side of comparison

• rhs – Right hand side of comparison

Returns:

Returns true if lhs is greater than rhs, false otherwise

class dictionary_column_view : private cudf::column_view

#include <dictionary_column_view.hpp>

A wrapper class for operations on a dictionary column.

A dictionary column contains a set of keys and a column of indices. The keys are a sorted set of unique values for the column. The indices represent the corresponding positions of each element’s value in the keys.

Public Functions

dictionary_column_view(column_view const &dictionary_column)

Construct a new dictionary column view object from a column view.

Parameters:

dictionary_column – The column view to wrap

dictionary_column_view(dictionary_column_view&&) = default

Move constructor.

dictionary_column_view(dictionary_column_view const&) = default

Copy constructor.

dictionary_column_view &operator=(dictionary_column_view const&) = default

Move assignment operator.

Returns:

The reference to this dictionary column

dictionary_column_view &operator=(dictionary_column_view&&) = default

Copy assignment operator.

Returns:

The reference to this dictionary column

column_view parent() const noexcept

Returns the parent column.

Returns:

The parent column

column_view indices() const noexcept

Returns the column of indices.

Returns:

The indices column

column_view get_indices_annotated() const noexcept

Returns a column_view combining the indices data with offset, size, and nulls from the parent.

Returns:

A sliced indices column view with nulls from the parent

column_view keys() const noexcept

Returns the column of keys.

Returns:

The keys column

data_type keys_type() const noexcept

Returns the cudf::data_type of the keys child column.

Returns:

The cudf::data_type of the keys child column

size_type keys_size() const noexcept

Returns the number of rows in the keys column.

Returns:

The number of rows in the keys column

Public Static Attributes

static constexpr size_type indices_column_index = {0}

Index of the indices column of the dictionary column.

static constexpr size_type keys_column_index = {1}

Index of the keys column of the dictionary column.

template<typename IndexType>
struct dictionary_wrapper

#include <dictionary.hpp>

A strongly typed wrapper for indices in a DICTIONARY type column.

IndexType will be integer types like int32_t.

For example, dictionary32 is a strongly typed wrapper around an int32_t value that holds the offset into the dictionary keys for a specific element.

This wrapper provides common conversion and comparison operations for the IndexType.

Public Types

using value_type = IndexType

The underlying type of the dictionary.

Public Functions

dictionary_wrapper(dictionary_wrapper&&) = default

Move constructor.

dictionary_wrapper(dictionary_wrapper const&) = default

Copy constructor.

dictionary_wrapper &operator=(dictionary_wrapper&&) = default

Move assignment operator.

Returns:

The reference to this dictionary wrapper object

dictionary_wrapper &operator=(dictionary_wrapper const&) = default

Copy assignment operator.

Returns:

The reference to this dictionary wrapper object

inline explicit constexpr dictionary_wrapper(value_type v)

Construct dictionary_wrapper from a value.

Parameters:

v – The value to construct the dictionary_wrapper from

inline explicit operator value_type() const

Conversion operator.

Returns:

The value of this dictionary wrapper

inline value_type value() const

Simple accessor.

Returns:

The value of this dictionary wrapper

Public Static Functions

static inline constexpr value_type max_value()

Returns the maximum value of the value type.

Returns:

The maximum value of the value type

static inline constexpr value_type min_value()

Returns the minimum value of the value type.

Returns:

The minimum value of the value type

static inline constexpr value_type lowest_value()

Returns the lowest value of the value type.

Returns:

The lowest value of the value type