#include </home/runner/work/Sleipnir/Sleipnir/include/sleipnir/autodiff/expression.hpp>

Public Types
using	Scalar = Scalar_
	Scalar type alias.

Public Member Functions
constexpr	Expression ()=default
	Constructs a constant expression with a value of zero.

constexpr	Expression (Scalar value)

constexpr	Expression (ExpressionPtr< Scalar > lhs)

constexpr	Expression (ExpressionPtr< Scalar > lhs, ExpressionPtr< Scalar > rhs)

constexpr bool	is_constant (Scalar constant) const

virtual Scalar	value (Scalar lhs, Scalar rhs) const =0

virtual ExpressionType	type () const =0

virtual std::string_view	name () const =0

virtual Scalar	grad_l (Scalar lhs, Scalar rhs) const

virtual Scalar	grad_r (Scalar lhs, Scalar rhs) const

virtual ExpressionPtr< Scalar >	grad_expr_l (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs) const

virtual ExpressionPtr< Scalar >	grad_expr_r (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs) const

Public Attributes
Scalar	val {0}
	The value of the expression node.

Scalar	adjoint {0}
	The adjoint of the expression node, used during autodiff.

ExpressionPtr< Scalar >	adjoint_expr

std::array< ExpressionPtr< Scalar >, 2 >	args {nullptr, nullptr}
	Expression arguments.

int32_t	scratch = -1

uint32_t	ref_count = 0
	Reference count for intrusive shared pointer.

Friends
ExpressionPtr< Scalar >	operator* (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)

ExpressionPtr< Scalar >	operator/ (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)

ExpressionPtr< Scalar >	operator+ (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)

ExpressionPtr< Scalar >	operator+= (ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)

ExpressionPtr< Scalar >	operator- (const ExpressionPtr< Scalar > &lhs, const ExpressionPtr< Scalar > &rhs)

ExpressionPtr< Scalar >	operator- (const ExpressionPtr< Scalar > &lhs)

ExpressionPtr< Scalar >	operator+ (const ExpressionPtr< Scalar > &lhs)

Detailed Description

template<typename Scalar_>
struct slp::detail::Expression< Scalar_ >

An autodiff expression node.

Template Parameters

Scalar Scalar type.

Constructor & Destructor Documentation

◆ Expression() [1/3]

template<typename Scalar_ >

constexpr slp::detail::Expression< Scalar_ >::Expression ( Scalar value )

inlineexplicitconstexpr

Constructs a nullary expression (an operator with no arguments).

Parameters

value The expression value.

◆ Expression() [2/3]

template<typename Scalar_ >

constexpr slp::detail::Expression< Scalar_ >::Expression ( ExpressionPtr< Scalar > lhs )

inlineexplicitconstexpr

Constructs an unary expression (an operator with one argument).

Parameters

lhs	Unary operator's operand.

◆ Expression() [3/3]

template<typename Scalar_ >

constexpr slp::detail::Expression< Scalar_ >::Expression	(	ExpressionPtr< Scalar >	lhs,
		ExpressionPtr< Scalar >	rhs
	)

inlineconstexpr

Constructs a binary expression (an operator with two arguments).

Parameters

lhs	Binary operator's left operand.
rhs	Binary operator's right operand.

Member Function Documentation

◆ grad_expr_l()

template<typename Scalar_ >

virtual ExpressionPtr< Scalar > slp::detail::Expression< Scalar_ >::grad_expr_l	(	const ExpressionPtr< Scalar > &	lhs,
		const ExpressionPtr< Scalar > &	rhs
	)		const

inlinevirtual

Returns ∂/∂l as an Expression.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.

Returns: ∂/∂l as an Expression.

◆ grad_expr_r()

template<typename Scalar_ >

virtual ExpressionPtr< Scalar > slp::detail::Expression< Scalar_ >::grad_expr_r	(	const ExpressionPtr< Scalar > &	lhs,
		const ExpressionPtr< Scalar > &	rhs
	)		const

inlinevirtual

Returns ∂/∂r as an Expression.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.

Returns: ∂/∂r as an Expression.

Reimplemented in slp::detail::BinaryMinusExpression< Scalar, T >, slp::detail::BinaryPlusExpression< Scalar, T >, slp::detail::MaxExpression< Scalar >, slp::detail::MinExpression< Scalar >, slp::detail::PowExpression< Scalar, T >, slp::detail::DivExpression< Scalar, T >, slp::detail::MultExpression< Scalar, T >, slp::detail::HypotExpression< Scalar >, and slp::detail::Atan2Expression< Scalar >.

◆ grad_l()

template<typename Scalar_ >

virtual Scalar slp::detail::Expression< Scalar_ >::grad_l	(	Scalar	lhs,
		Scalar	rhs
	)		const

inlinevirtual

Returns ∂/∂l as a Scalar.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.

Returns: ∂/∂l as a Scalar.

◆ grad_r()

template<typename Scalar_ >

virtual Scalar slp::detail::Expression< Scalar_ >::grad_r	(	Scalar	lhs,
		Scalar	rhs
	)		const

inlinevirtual

Returns ∂/∂r as a Scalar.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.

Returns: ∂/∂r as a Scalar.

Reimplemented in slp::detail::MaxExpression< Scalar >, slp::detail::MinExpression< Scalar >, slp::detail::PowExpression< Scalar, T >, slp::detail::DivExpression< Scalar, T >, slp::detail::MultExpression< Scalar, T >, slp::detail::HypotExpression< Scalar >, slp::detail::Atan2Expression< Scalar >, slp::detail::BinaryMinusExpression< Scalar, T >, and slp::detail::BinaryPlusExpression< Scalar, T >.

◆ is_constant()

template<typename Scalar_ >

constexpr bool slp::detail::Expression< Scalar_ >::is_constant ( Scalar constant ) const

inlineconstexpr

Returns true if the expression is the given constant.

Parameters

constant The constant.

Returns: True if the expression is the given constant.

◆ name()

template<typename Scalar_ >

virtual std::string_view slp::detail::Expression< Scalar_ >::name ( ) const

pure virtual

Returns the name of this expression.

Returns: The name of this expression.

◆ type()

template<typename Scalar_ >

virtual ExpressionType slp::detail::Expression< Scalar_ >::type ( ) const

pure virtual

Returns the type of this expression (constant, linear, quadratic, or nonlinear).

Returns: The type of this expression.

◆ value()

template<typename Scalar_ >

virtual Scalar slp::detail::Expression< Scalar_ >::value	(	Scalar	lhs,
		Scalar	rhs
	)		const

pure virtual

Either nullary operator with no arguments, unary operator with one argument, or binary operator with two arguments. This operator is used to update the node's value.

Parameters

lhs	Left argument to binary operator.
rhs	Right argument to binary operator.

Returns: The node's value.

Friends And Related Symbol Documentation

◆ operator*

template<typename Scalar_ >

ExpressionPtr< Scalar > operator*	(	const ExpressionPtr< Scalar > &	lhs,
		const ExpressionPtr< Scalar > &	rhs
	)

friend

Expression-Expression multiplication operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

◆ operator+ [1/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator+ ( const ExpressionPtr< Scalar > & lhs )

friend

Unary plus operator.

Parameters

lhs	Operand of unary plus.

◆ operator+ [2/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator+	(	const ExpressionPtr< Scalar > &	lhs,
		const ExpressionPtr< Scalar > &	rhs
	)

friend

Expression-Expression addition operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

◆ operator+=

template<typename Scalar_ >

ExpressionPtr< Scalar > operator+=	(	ExpressionPtr< Scalar > &	lhs,
		const ExpressionPtr< Scalar > &	rhs
	)

friend

Expression-Expression compound addition operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

◆ operator- [1/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator- ( const ExpressionPtr< Scalar > & lhs )

friend

Unary minus operator.

Parameters

lhs	Operand of unary minus.

◆ operator- [2/2]

template<typename Scalar_ >

ExpressionPtr< Scalar > operator-	(	const ExpressionPtr< Scalar > &	lhs,
		const ExpressionPtr< Scalar > &	rhs
	)

friend

Expression-Expression subtraction operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

◆ operator/

template<typename Scalar_ >

ExpressionPtr< Scalar > operator/	(	const ExpressionPtr< Scalar > &	lhs,
		const ExpressionPtr< Scalar > &	rhs
	)

friend

Expression-Expression division operator.

Parameters

lhs	Operator left-hand side.
rhs	Operator right-hand side.

Member Data Documentation

◆ adjoint_expr

template<typename Scalar_ >

ExpressionPtr<Scalar> slp::detail::Expression< Scalar_ >::adjoint_expr

The adjoint of the expression node, used during gradient expression tree generation.

◆ scratch

template<typename Scalar_ >

int32_t slp::detail::Expression< Scalar_ >::scratch = -1

Scratch space for various graph algorithms.

In expression_graph.hpp's topological_sort(), scratch counts incoming edges for this node, offset by -1 so -1 means no edges.

In Hessian and Jacobian constructors, scratch represents this expression's column in a Jacobian, or -1 otherwise.

They share a default state of -1 to avoid extra assignments.

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

/home/runner/work/Sleipnir/Sleipnir/include/sleipnir/autodiff/expression.hpp

Public Types

Public Member Functions

Public Attributes

Friends

Detailed Description

Constructor & Destructor Documentation

◆ Expression() [1/3]

◆ Expression() [2/3]

◆ Expression() [3/3]

Member Function Documentation

◆ grad_expr_l()

◆ grad_expr_r()

◆ grad_l()

◆ grad_r()

◆ is_constant()

◆ name()

◆ type()

◆ value()

Friends And Related Symbol Documentation

◆ operator*

◆ operator+ [1/2]

◆ operator+ [2/2]

◆ operator+=

◆ operator- [1/2]

◆ operator- [2/2]

◆ operator/

Member Data Documentation

◆ adjoint_expr

◆ scratch