pl_search::PVar Class Reference

Represents a Prolog variable. More...

#include <pvar.hpp>

Inheritance diagram for pl_search::PVar:

Collaboration diagram for pl_search::PVar:

Public Member Functions
	PVar ()
	Constructs a PVar.
TermPtr	dereference () override
	Dereferences the variable to find the actual term it points to.
virtual bool	bind (const TermPtr &t)
	Binds the variable to a term.
void	reset (const TermPtr &t)
	Resets the variable to point at the supplied term.
bool	is_var () override
	Checks if the term is a variable.
bool	isLessThan (Term &other) const override
	Checks if the variable is less than another term.
int	getVarId () const
	Returns the variable ID.
std::string	repr () const override
	Returns a string representation of the term.
Public Member Functions inherited from pl_search::Term
virtual bool	unifyWith (Engine *engine, TermPtr t)
	A hook for unification of user-defined classes. Only override this method if you want to unify user-defined classes.
	Term ()
	Default constructor.
virtual	~Term ()
	Virtual destructor for proper cleanup.

Public Attributes
TermPtr	value
	The value of the variable.

Static Public Attributes
static int	id = 0
	Static member to generate unique IDs for variables.

Protected Member Functions
virtual bool	isEqualTo (Term &other) const override
	Checks if the term is equal to another term.
Term *	deref_term () override
	Similar to dereference but returning the "raw" pointer.

Protected Attributes
int	var_id
	The ID of the variable.

Detailed Description

Represents a Prolog variable.

PVar objects approximate Prolog variables. Variables can be bound to other terms. An unbound variable is represented by a PVar object with a null value.

Constructor & Destructor Documentation

PVar()

pl_search::PVar::PVar ( )

inline

Constructs a PVar.

Member Function Documentation

bind()

bool pl_search::PVar::bind ( const TermPtr &  t )

virtual

Binds the variable to a term.

Parameters

t	The term to bind to.

Returns

True if the binding is successful, false otherwise. Precondition: t has been dereferenced before the call (bind is only called from unify)

deref_term()

Term * pl_search::PVar::deref_term ( )

overrideprotectedvirtual

Similar to dereference but returning the "raw" pointer.

Returns

A pointer to the dereferenced term. WARNING: This should only be used for testing as it returns the raw pointer of a shared_ptr.

Reimplemented from pl_search::Term.

Reimplemented in pl_search::UpdatablePVar.

dereference()

TermPtr pl_search::PVar::dereference ( )

overridevirtual

Dereferences the variable to find the actual term it points to.

Returns

A pointer to the dereferenced term.

Reimplemented from pl_search::Term.

Reimplemented in pl_search::UpdatablePVar.

getVarId()

int pl_search::PVar::getVarId ( ) const

inline

Returns the variable ID.

Returns

The variable ID.

is_var()

bool pl_search::PVar::is_var ( )

overridevirtual

Checks if the term is a variable.

Returns

True if the term is a variable, false otherwise.

Reimplemented from pl_search::Term.

isEqualTo()

virtual bool pl_search::PVar::isEqualTo ( Term &  t ) const

inlineoverrideprotectedvirtual

Checks if the term is equal to another term.

Parameters

t	The term to compare to.

Returns

True if the terms are equal, false otherwise.

Implements pl_search::Term.

isLessThan()

bool pl_search::PVar::isLessThan ( Term &  t ) const

overridevirtual

Checks if the variable is less than another term.

Parameters

t	The term to compare to.

Returns

True if the variable is less than the other term, false otherwise.

Implements pl_search::Term.

repr()

std::string pl_search::PVar::repr ( ) const

inlineoverridevirtual

Returns a string representation of the term.

Returns

A string representation of the term.

Reimplemented from pl_search::Term.

reset()

void pl_search::PVar::reset

(

const TermPtr &

t

)

Resets the variable to point at the supplied term.

Parameters

t	The term to reset to.

Member Data Documentation

id

int pl_search::PVar::id = 0

static

Static member to generate unique IDs for variables.

value

TermPtr pl_search::PVar::value

The value of the variable.

var_id

int pl_search::PVar::var_id

protected

The ID of the variable.

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

• include/pl_search/pvar.hpp
• src/pvar.cpp