cudf::ast::expression Struct Reference

A generic expression that can be evaluated to return a value. More...

#include <expressions.hpp>

Inheritance diagram for cudf::ast::expression:

Public Member Functions
virtual cudf::size_type	accept (detail::expression_parser &visitor) const =0
	Accepts a visitor class. More...
virtual std::reference_wrapper< expression const >	accept (detail::expression_transformer &visitor) const =0
	Accepts a visitor class. More...
bool	may_evaluate_null (table_view const &left, rmm::cuda_stream_view stream) const
	Returns true if the expression may evaluate to null. More...
virtual bool	may_evaluate_null (table_view const &left, table_view const &right, rmm::cuda_stream_view stream) const =0
	Returns true if the expression may evaluate to null. More...

Detailed Description

A generic expression that can be evaluated to return a value.

This class is a part of a "visitor" pattern with the expression_parser class. Expressions inheriting from this class can accept parsers as visitors.

Definition at line 41 of file expressions.hpp.

Member Function Documentation

accept() [1/2]

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

pure virtual

Accepts a visitor class.

Parameters

visitor

The expression_parser parsing this expression tree

Returns

Index of device data reference for this instance

Implemented in cudf::ast::column_name_reference, cudf::ast::operation, cudf::ast::column_reference, and cudf::ast::literal.

accept() [2/2]

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

pure virtual

Accepts a visitor class.

Parameters

visitor

The expression_transformer transforming this expression tree

Returns

Reference wrapper of transformed expression

Implemented in cudf::ast::column_name_reference, cudf::ast::operation, cudf::ast::column_reference, and cudf::ast::literal.

may_evaluate_null() [1/2]

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

inline

Returns true if the expression may evaluate to null.

Parameters

left	The left operand of the expression (The same is used as right operand)
stream	CUDA stream used for device memory operations and kernel launches

Returns

true if the expression may evaluate to null, otherwise false

Definition at line 66 of file expressions.hpp.

may_evaluate_null() [2/2]

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

pure virtual

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

Implemented in cudf::ast::column_name_reference, cudf::ast::operation, cudf::ast::column_reference, and cudf::ast::literal.

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

• expressions.hpp