#include <booleanExpression.h>

Public Types
enum	BinaryOperator { BinaryOperator::EqualTo, BinaryOperator::NotEqualTo, BinaryOperator::LessThan, BinaryOperator::LessThanOrEqualTo, BinaryOperator::GreaterThan, BinaryOperator::GreaterThanOrEqualTo, BinaryOperator::And, BinaryOperator::Or }

enum	UnaryOperator { UnaryOperator::Not }

using	BinaryVisitor = TfFunctionRef< void(SdfBooleanExpression const &, BinaryOperator, SdfBooleanExpression const &)>

using	UnaryVisitor = TfFunctionRef< void(SdfBooleanExpression const &, UnaryOperator)>

using	VariableVisitor = TfFunctionRef< void(TfToken const &)>

using	ConstantVisitor = TfFunctionRef< void(VtValue const &)>

using	VariableCallback = TfFunctionRef< VtValue(TfToken const &)>

using	NameTransform = TfFunctionRef< TfToken(TfToken const &)>

Public Member Functions
	SdfBooleanExpression ()=default
	Constructs an empty expression. More...

SDF_API	SdfBooleanExpression (std::string const &text)

SDF_API bool	IsEmpty () const

SDF_API std::string	GetText () const

SDF_API std::string const &	GetParseError () const

SDF_API std::set< TfToken >	GetVariableNames () const
	Provides the collection of variable names referenced by the expression. More...

SDF_API void	Visit (VariableVisitor variable, ConstantVisitor constant, BinaryVisitor binary, UnaryVisitor unary) const
	Invokes one of the given callbacks based on the type of the expression. More...

SDF_API bool	Evaluate (VariableCallback const &variableCallback) const

SDF_API SdfBooleanExpression	RenameVariables (NameTransform const &transform) const

	TF_DECLARE_REF_PTRS (_Node)

Static Public Member Functions
static SDF_API SdfBooleanExpression	MakeVariable (TfToken const &variableName)

static SDF_API SdfBooleanExpression	MakeConstant (VtValue const &value)

static SDF_API SdfBooleanExpression	MakeBinaryOp (SdfBooleanExpression lhs, BinaryOperator op, SdfBooleanExpression rhs)

static SDF_API SdfBooleanExpression	MakeUnaryOp (SdfBooleanExpression expression, UnaryOperator op)

static SDF_API bool	Validate (std::string const &expression, std::string *errorMessage=nullptr)

Friends
SDF_API friend std::ostream &	operator<< (std::ostream &, SdfBooleanExpression const &)

Detailed Description

Objects of this class represent expressions that can be evaluated to produce a boolean value. See Sdf_Page_BooleanExpressions for more details.

Definition at line 29 of file booleanExpression.h.

Member Typedef Documentation

using SdfBooleanExpression::BinaryVisitor = TfFunctionRef<void(SdfBooleanExpression const&, BinaryOperator, SdfBooleanExpression const&)>

The Visit() method will invoke this callback if the receiver represents a binary operator applied to two subexpressions.

Given the expression width > 10.0, the callback would be invoked with the arguments:

argument	value
lhs	SdfBooleanExpression representing `width`
op	BinaryOperator::GreaterThan
rhs	SdfBooleanExpression representing `10.0`

See Also: MakeBinaryOp()

Definition at line 144 of file booleanExpression.h.

using SdfBooleanExpression::ConstantVisitor = TfFunctionRef<void(VtValue const&)>

The Visit() method will invoke this callback if the receiver represents a constant.

See Also: MakeConstant()

Definition at line 169 of file booleanExpression.h.

using SdfBooleanExpression::NameTransform = TfFunctionRef<TfToken(TfToken const&)>

Encapsulates a transformation that may be applied to a variable name. Used by RenameVariables().

Definition at line 187 of file booleanExpression.h.

using SdfBooleanExpression::UnaryVisitor = TfFunctionRef<void(SdfBooleanExpression const&, UnaryOperator)>

The Visit() method will invoke this callback if the receiver represents an operator applied to a single subexpression

Given the expression !(width > 10.0), the callback would be invoked with the arguments:

argument	value
expression	SdfBooleanExpression representing `width > 10.0`
op	UnaryOp::Not

See Also: MakeUnaryOp()

Definition at line 157 of file booleanExpression.h.

using SdfBooleanExpression::VariableCallback = TfFunctionRef<VtValue (TfToken const&)>

Provides the current value for a given variable. Used by Evaluate() when evaluating the expression.

Definition at line 179 of file booleanExpression.h.

using SdfBooleanExpression::VariableVisitor = TfFunctionRef<void(TfToken const&)>

The Visit() method will invoke this callback if the receiver represents a variable.

See Also: MakeVariable()

Definition at line 163 of file booleanExpression.h.

Member Enumeration Documentation

enum SdfBooleanExpression::BinaryOperator

strong

Operators for combining two subexpressions.

See Also: MakeBinaryOp

Enumerator
EqualTo	The `==` operator.
NotEqualTo	The `!=` operator.
LessThan	The `<` operator.
LessThanOrEqualTo	The `<=` operator.
GreaterThan	The `>` operator.
GreaterThanOrEqualTo	The `>=` operator.
And	The `&&` operator.
Or	The `\|\|` operator.

Definition at line 70 of file booleanExpression.h.

enum SdfBooleanExpression::UnaryOperator

strong

Operators applied to a single subexpression.

See Also: MakeUnaryOp

Enumerator
Not	The `!` operator.

Definition at line 113 of file booleanExpression.h.

Constructor & Destructor Documentation

SdfBooleanExpression::SdfBooleanExpression ( )

default

Constructs an empty expression.

SDF_API SdfBooleanExpression::SdfBooleanExpression ( std::string const & text )

explicit

Constructs an expression by parsing a string representation. If an error occurs while parsing the string, the result will be an empty expression. See also GetParseError().

Member Function Documentation

SDF_API bool SdfBooleanExpression::Evaluate ( VariableCallback const & variableCallback ) const

Evaluates the expression. If the expression contains any variables, variableCallback will be invoked to determine their current values.

SDF_API std::string const& SdfBooleanExpression::GetParseError ( ) const

Return parsing errors as a string if this expression was constructed from a string and parse errors were encountered.

SDF_API std::string SdfBooleanExpression::GetText ( ) const

Provides a string representation that can be parsed by SdfBooleanExpression(std::string const&). If the expression was constructed from a string, the existing formatting will be preserved.

SDF_API std::set<TfToken> SdfBooleanExpression::GetVariableNames ( ) const

Provides the collection of variable names referenced by the expression.

SDF_API bool SdfBooleanExpression::IsEmpty ( ) const

An expression is empty if it was default constructed or if there was a problem parsing its string representation.

static SDF_API SdfBooleanExpression SdfBooleanExpression::MakeBinaryOp	(	SdfBooleanExpression	lhs,
		BinaryOperator	op,
		SdfBooleanExpression	rhs
	)

static

Constructs an expression that applies the provided operator to the result of the two provided subexpressions.

The expression width > 10.0 would be constructed with the arguments:

argument	value
lhs	`SdfBooleanExpression::MakeVariable(TfToken("width"));`
op	BinaryOperator::GreaterThan
rhs	`SdfBooleanExpression::MakeConstant(VtValue(10.0));`

See Also: BinaryVisitor

static SDF_API SdfBooleanExpression SdfBooleanExpression::MakeConstant ( VtValue const & value )

static

Constructs an expression wrapping a constant value.

See Also: ConstantVisitor

static SDF_API SdfBooleanExpression SdfBooleanExpression::MakeUnaryOp	(	SdfBooleanExpression	expression,
		UnaryOperator	op
	)

static

Constructs an expression that applies the provided operator to the result of the provided subexpression.

The expression !(width > 10.0) would be constructed with the arguments:

argument	value
expression	SdfBooleanExpression representing `width > 10.0`
op	UnaryOp::Not

See Also: UnaryVisitor

static SDF_API SdfBooleanExpression SdfBooleanExpression::MakeVariable ( TfToken const & variableName )

static

Constructs an expression representing a variable.

See Also: VariableVisitor

SDF_API SdfBooleanExpression SdfBooleanExpression::RenameVariables ( NameTransform const & transform ) const

Applies the provided transform to each variable name and returns the resulting expression.

SdfBooleanExpression::TF_DECLARE_REF_PTRS ( _Node )

static SDF_API bool SdfBooleanExpression::Validate	(	std::string const &	expression,
		std::string *	errorMessage = `nullptr`
	)

static

Determines if the provided string can be parsed as an expression. Returns true if the expression is valid, otherwise returns false. If the string is not a valid expression, errorMessage (if non-null) will be filled with an explanatory error message.

SDF_API void SdfBooleanExpression::Visit	(	VariableVisitor	variable,
		ConstantVisitor	constant,
		BinaryVisitor	binary,
		UnaryVisitor	unary
	)		const

Invokes one of the given callbacks based on the type of the expression.

Friends And Related Function Documentation

SDF_API friend std::ostream& operator<<	(	std::ostream &	,
		SdfBooleanExpression const &
	)

friend

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

pxr/usd/sdf/booleanExpression.h

Public Types

Public Member Functions

Static Public Member Functions

Friends

Detailed Description

Member Typedef Documentation

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Friends And Related Function Documentation