cudf::list_device_view Class Reference

A non-owning, immutable view of device data that represents a list of elements of arbitrary type (including further nested lists). More...

Classes
struct	pair_accessor
	pair accessor for elements in a list_device_view More...

Public Types
template<typename T >
using	const_pair_iterator = thrust::transform_iterator< pair_accessor< T >, thrust::counting_iterator< cudf::size_type > >

Public Member Functions
CUDA_DEVICE_CALLABLE	list_device_view (lists_column_device_view const &lists_column, size_type const &row_index)
CUDA_DEVICE_CALLABLE size_type	element_offset (size_type idx) const
	Fetches the offset in the list column's child that corresponds to the element at the specified list index. More...
template<typename T >
CUDA_DEVICE_CALLABLE T	element (size_type idx) const
	Fetches the element at the specified index within the list row. More...
CUDA_DEVICE_CALLABLE bool	is_null (size_type idx) const
	Checks whether element is null at specified index in the list row.
CUDA_DEVICE_CALLABLE bool	is_null () const
	Checks whether this list row is null.
CUDA_DEVICE_CALLABLE size_type	size () const
	Fetches the number of elements in this list row.
CUDA_DEVICE_CALLABLE lists_column_device_view const &	get_column () const
	Fetches the lists_column_device_view that contains this list.
template<typename T >
CUDA_DEVICE_CALLABLE const_pair_iterator< T >	pair_begin () const
	Fetcher for a pair iterator to the first element in the list_device_view. More...
template<typename T >
CUDA_DEVICE_CALLABLE const_pair_iterator< T >	pair_end () const
	Fetcher for a pair iterator to one position past the last element in the list_device_view.

Detailed Description

A non-owning, immutable view of device data that represents a list of elements of arbitrary type (including further nested lists).

Definition at line 28 of file list_device_view.cuh.

Member Function Documentation

element()

template<typename T >

CUDA_DEVICE_CALLABLE T cudf::list_device_view::element ( size_type  idx ) const

inline

Fetches the element at the specified index within the list row.

Template Parameters

The	type of the list's element.

Parameters

The	index into the list row

Returns

The element at the specified index of the list row.

Definition at line 85 of file list_device_view.cuh.

element_offset()

CUDA_DEVICE_CALLABLE size_type cudf::list_device_view::element_offset ( size_type  idx ) const

inline

Fetches the offset in the list column's child that corresponds to the element at the specified list index.

Consider the following lists column: [ [0,1,2], [3,4,5], [6,7,8] ]

The list's internals would look like: offsets: [0, 3, 6, 9] child : [0, 1, 2, 3, 4, 5, 6, 7, 8]

The second list row (i.e. row_index=1) is [3,4,5]. The third element (i.e. idx=2) of the second list row is 5.

The offset of this element as stored in the child column (i.e. 5) may be fetched using this method.

Definition at line 71 of file list_device_view.cuh.

pair_begin()

template<typename T >

CUDA_DEVICE_CALLABLE const_pair_iterator<T> cudf::list_device_view::pair_begin ( ) const

inline

Fetcher for a pair iterator to the first element in the list_device_view.

Dereferencing the returned iterator yields a thrust::pair<T, bool>.

If the element at index i is valid, then for p = iter[i],

1. p.first is the value of the element at i
2. p.second == true

If the element at index i is null,

1. p.first is undefined
2. p.second == false

Definition at line 136 of file list_device_view.cuh.

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The documentation for this class was generated from the following file:

• list_device_view.cuh