cudf::ast::column_reference Class Reference

A expression referring to data from a column in a table. More...

#include <expressions.hpp>

Inheritance diagram for cudf::ast::column_reference:

Public Member Functions
	column_reference (cudf::size_type column_index, table_reference table_source=table_reference::LEFT)
	Construct a new column reference object. More...
cudf::size_type	get_column_index () const
	Get the column index. More...
table_reference	get_table_source () const
	Get the table source. More...
cudf::data_type	get_data_type (table_view const &table) const
	Get the data type. More...
cudf::data_type	get_data_type (table_view const &left_table, table_view const &right_table) const
	Get the data type. More...
cudf::size_type	accept (detail::expression_parser &visitor) const override
	Accepts a visitor class. More...
std::reference_wrapper< expression const >	accept (detail::expression_transformer &visitor) const override
	Accepts a visitor class. More...
bool	may_evaluate_null (table_view const &left, table_view const &right, rmm::cuda_stream_view stream) const override
	Returns true if the expression may evaluate to null. More...
Public Member Functions inherited from cudf::ast::expression
bool	may_evaluate_null (table_view const &left, rmm::cuda_stream_view stream) const
	Returns true if the expression may evaluate to null. More...

Detailed Description

A expression referring to data from a column in a table.

Definition at line 355 of file expressions.hpp.

Constructor & Destructor Documentation

column_reference()

cudf::ast::column_reference::column_reference ( cudf::size_type  column_index, table_reference  table_source = table_reference::LEFT  )

inline

Construct a new column reference object.

Parameters

column_index	Index of this column in the table (provided when the expression is evaluated).
table_source	Which table to use in cases with two tables (e.g. joins)

Definition at line 364 of file expressions.hpp.

Member Function Documentation

accept() [1/2]

cudf::size_type cudf::ast::column_reference::accept ( detail::expression_parser &  visitor ) const

overridevirtual

Accepts a visitor class.

Parameters

visitor

The expression_parser parsing this expression tree

Returns

Index of device data reference for this instance

Implements cudf::ast::expression.

accept() [2/2]

std::reference_wrapper<expression const> cudf::ast::column_reference::accept ( detail::expression_transformer &  visitor ) const

overridevirtual

Accepts a visitor class.

Parameters

visitor

The expression_parser parsing this expression tree

Returns

Index of device data reference for this instance

Implements cudf::ast::expression.

get_column_index()

cudf::size_type cudf::ast::column_reference::get_column_index ( ) const

inline

Get the column index.

Returns

The column index of the column reference

Definition at line 375 of file expressions.hpp.

get_data_type() [1/2]

cudf::data_type cudf::ast::column_reference::get_data_type ( table_view const &  left_table, table_view const &  right_table  ) const

inline

Get the data type.

Parameters

left_table	Left table used to determine types
right_table	Right table used to determine types

Returns

The data type of the column

Definition at line 402 of file expressions.hpp.

get_data_type() [2/2]

cudf::data_type cudf::ast::column_reference::get_data_type ( table_view const &  table ) const

inline

Get the data type.

Parameters

table

Table used to determine types

Returns

The data type of the column

Definition at line 390 of file expressions.hpp.

get_table_source()

table_reference cudf::ast::column_reference::get_table_source ( ) const

inline

Get the table source.

Returns

table_reference The reference to the table containing this column

Definition at line 382 of file expressions.hpp.

may_evaluate_null()

bool cudf::ast::column_reference::may_evaluate_null ( table_view const &  left, table_view const &  right, rmm::cuda_stream_view  stream  ) const

inlineoverridevirtual

Returns true if the expression may evaluate to null.

Parameters

left	The left operand of the expression
right	The right operand of the expression
stream	CUDA stream used for device memory operations and kernel launches

Returns

true if the expression may evaluate to null, otherwise false

Implements cudf::ast::expression.

Definition at line 428 of file expressions.hpp.

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

• expressions.hpp