Represents an abstract class which is the base of concrete symbolic-expression classes. More...

#include <symbolic_expression_cell.h>

Inheritance diagram for dlinear::drake::symbolic::ExpressionCell:

Public Member Functions
ExpressionKind	get_kind () const
	Returns expression kind.

size_t	get_hash () const
	Returns hash value.

const Variables &	GetVariables () const
	Collects variables in expression.

virtual bool	EqualTo (const ExpressionCell &c) const =0
	Checks structural equality.

virtual bool	Less (const ExpressionCell &c) const =0
	Provides lexicographical ordering between expressions.

bool	is_polynomial () const
	Checks if this symbolic expression is convertible to Polynomial.

bool	include_ite () const
	Returns true if this symbolic expression includes an ITE (If-Then-Else) expression.

virtual mpq_class	Evaluate (const Environment &env) const =0
	Evaluates under a given environment (by default, an empty environment).

virtual Expression	Expand ()=0
	Expands out products and positive integer powers in expression.

virtual Expression	Substitute (const ExpressionSubstitution &expr_subst, const FormulaSubstitution &formula_subst)=0
	Returns an Expression obtained by replacing all occurrences of the variables in `s` in the current expression cell with the corresponding expressions in `s`.

virtual Expression	Differentiate (const Variable &x) const =0
	Differentiates this symbolic expression with respect to the variable `var`.

virtual std::ostream &	Display (std::ostream &os) const =0
	Outputs string representation of expression into output stream `os`.

unsigned	use_count () const
	Returns the reference count of this cell.

	ExpressionCell (const ExpressionCell &e)=delete
	Copy-constructs an ExpressionCell from an lvalue.

	ExpressionCell (ExpressionCell &&e)=delete
	Move-constructs an ExpressionCell from an rvalue.

ExpressionCell &	operator= (ExpressionCell &&e)=delete
	Move-assigns (DELETED).

ExpressionCell &	operator= (const ExpressionCell &e)=delete
	Copy-assigns (DELETED).

virtual void	UpdateHash ()
	Update the cached hash value.

Protected Member Functions
	ExpressionCell (ExpressionKind k)
	Constructs ExpressionCell of kind `k`.

	ExpressionCell (ExpressionKind k, bool is_poly)
	Constructs ExpressionCell of kind `k` with `hash`, `is_poly`, and `include_ite`.

	ExpressionCell (ExpressionKind k, bool is_poly, bool include_ite)
	Constructs ExpressionCell of kind `k` with `hash`, `is_poly`, and `include_ite`.

	ExpressionCell (ExpressionKind k, bool is_poly, bool include_ite, Variables variables)
	Constructs ExpressionCell of kind `k` with `hash`, `is_poly`, and `include_ite`.

	ExpressionCell (ExpressionKind k, bool is_poly, bool include_ite, Variables variables, size_t hash)
	Constructs ExpressionCell of kind `k` with `hash`, `is_poly`, and `include_ite`.

virtual	~ExpressionCell ()=default
	Default destructor.

Expression	GetExpression ()
	Returns an expression pointing to this ExpressionCell.

Private Attributes
std::optional< Variables >	variables_
	Cached variables contained in the expression.

Detailed Description

Represents an abstract class which is the base of concrete symbolic-expression classes.

Note: It provides virtual function, ExpressionCell::Display, because operator<< is not allowed to be a virtual function.

Definition at line 26 of file symbolic_expression_cell.h.

Constructor & Destructor Documentation

◆ ExpressionCell() [1/2]

dlinear::drake::symbolic::ExpressionCell::ExpressionCell ( const ExpressionCell & e )

delete

Copy-constructs an ExpressionCell from an lvalue.

(DELETED)

◆ ExpressionCell() [2/2]

dlinear::drake::symbolic::ExpressionCell::ExpressionCell ( ExpressionCell && e )

delete

Move-constructs an ExpressionCell from an rvalue.

(DELETED)

Member Function Documentation

◆ Differentiate()

virtual Expression dlinear::drake::symbolic::ExpressionCell::Differentiate ( const Variable & x ) const

pure virtual

Differentiates this symbolic expression with respect to the variable var.

Exceptions

std::runtime_error if it is not differentiable.

◆ Evaluate()

virtual mpq_class dlinear::drake::symbolic::ExpressionCell::Evaluate ( const Environment & env ) const

pure virtual

Evaluates under a given environment (by default, an empty environment).

Exceptions

std::runtime_error if NaN is detected during evaluation.

Implemented in dlinear::drake::symbolic::BinaryExpressionCell, dlinear::drake::symbolic::ExpressionAdd, dlinear::drake::symbolic::ExpressionConstant, dlinear::drake::symbolic::ExpressionIfThenElse, dlinear::drake::symbolic::ExpressionInfty, dlinear::drake::symbolic::ExpressionMul, dlinear::drake::symbolic::ExpressionNaN, dlinear::drake::symbolic::ExpressionUninterpretedFunction, dlinear::drake::symbolic::ExpressionVar, and dlinear::drake::symbolic::UnaryExpressionCell.

◆ Expand()

virtual Expression dlinear::drake::symbolic::ExpressionCell::Expand ( )

pure virtual

Expands out products and positive integer powers in expression.

Exceptions

std::runtime_error if NaN is detected during expansion.

◆ Substitute()

virtual Expression dlinear::drake::symbolic::ExpressionCell::Substitute	(	const ExpressionSubstitution &	expr_subst,
		const FormulaSubstitution &	formula_subst )

pure virtual

Returns an Expression obtained by replacing all occurrences of the variables in s in the current expression cell with the corresponding expressions in s.

Exceptions

std::runtime_error if NaN is detected during substitution.

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

third_party/com_github_robotlocomotion_drake/dlinear/symbolic/symbolic_expression_cell.h

Public Member Functions

Protected Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ ExpressionCell() [1/2]

◆ ExpressionCell() [2/2]

Member Function Documentation

◆ Differentiate()

◆ Evaluate()

◆ Expand()

◆ Substitute()