#include <BindLink.h>

Inheritance diagram for opencog::BindLink:

Collaboration diagram for opencog::BindLink:

Public Member Functions
	BindLink (const HandleSeq &, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	BindLink (Link &l)

bool	imply (PatternMatchCallback &, bool check_connectivity=true)

const Handle &	get_implicand (void)

Public Member Functions inherited from opencog::PatternLink
	PatternLink (const HandleSeq &, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	PatternLink (const Handle &body, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	PatternLink (const Handle &varcdecls, const Handle &body, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	PatternLink (Link &l)

	PatternLink (const std::set< Handle > &vars, const VariableTypeMap &typemap, const HandleSeq &component, const std::set< Handle > &optionals)

	PatternLink (const std::set< Handle > &, const HandleSeq &)

const Variables &	get_variables (void) const

const Handle &	get_body (void) const

const Pattern &	get_pattern (void)

bool	satisfy (PatternMatchCallback &) const

void	debug_print (void) const

Public Member Functions inherited from opencog::Link
	Link (Type t, const HandleSeq &oset, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	Link (Type t, const Handle &h, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	Link (Type t, const Handle &ha, const Handle &hb, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	Link (Type t, const Handle &ha, const Handle &hb, const Handle &hc, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	Link (Type t, const Handle &ha, const Handle &hb, const Handle &hc, const Handle &hd, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

	Link (Link &l)

	~Link ()

Arity	getArity () const

const HandleSeq &	getOutgoingSet () const

Handle	getOutgoingAtom (Arity pos) const throw (RuntimeException)

template<class T >
bool	foreach_outgoing (bool(T::cb)(const Handle &), T data)

std::string	toString (std::string indent="")

std::string	toShortString (std::string indent="")

bool	isSource (Handle) const throw (InvalidParamException)

bool	isSource (size_t) const throw (IndexErrorException, InvalidParamException)

bool	isTarget (Handle) const throw (InvalidParamException)

bool	isTarget (size_t) const throw (IndexErrorException, InvalidParamException)

virtual bool	operator== (const Atom &) const

virtual bool	operator!= (const Atom &) const

Public Member Functions inherited from opencog::Atom
virtual	~Atom ()

Type	getType () const

bool	isType (Type t, bool subclass) const

Handle	getHandle ()

AttentionValuePtr	getAttentionValue ()

void	setAttentionValue (AttentionValuePtr)
	Sets the AttentionValue object of the atom. More...

AttentionValue::sti_t	getSTI ()
	Handy-dandy convenience getters for attention values. More...

AttentionValue::lti_t	getLTI ()

AttentionValue::vlti_t	getVLTI ()

void	setSTI (AttentionValue::sti_t stiValue)

void	setLTI (AttentionValue::lti_t ltiValue)

void	incVLTI ()

void	decVLTI ()

TruthValuePtr	getTruthValue ()

void	setTruthValue (TruthValuePtr)
	Sets the TruthValue object of the atom. More...

void	merge (TruthValuePtr)

Handle	tvmerge (TruthValuePtr tv)

size_t	getIncomingSetSize ()
	Get the size of the incoming set. More...

IncomingSet	getIncomingSet ()

template<typename OutputIterator >
OutputIterator	getIncomingSet (OutputIterator result)

template<class T >
bool	foreach_incoming (bool(T::cb)(const Handle &), T data)

template<typename OutputIterator >
OutputIterator	getIncomingSetByType (OutputIterator result, Type type, bool subclass=false)

IncomingSet	getIncomingSetByType (Type type, bool subclass=false)

Protected Member Functions
void	init (void)

void	extract_variables (const HandleSeq &oset)

	BindLink (Type, const HandleSeq &, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

Protected Member Functions inherited from opencog::PatternLink
void	extract_variables (const HandleSeq &oset)

void	init_scoped_variables (const Handle &hvar)

void	unbundle_clauses (const Handle &body)

void	validate_clauses (std::set< Handle > &vars, HandleSeq &clauses)

void	extract_optionals (const std::set< Handle > &vars, const std::vector< Handle > &component)

void	unbundle_virtual (const std::set< Handle > &vars, const HandleSeq &clauses, HandleSeq &concrete_clauses, HandleSeq &virtual_clauses, std::set< Handle > &black_clauses)

void	trace_connectives (const std::set< Type > &, const HandleSeq &clauses)

void	make_connectivity_map (const HandleSeq &)

void	check_connectivity (const std::vector< HandleSeq > &)

void	make_map_recursive (const Handle &, const Handle &)

void	make_term_trees ()

void	make_term_tree_recursive (const Handle &, const Handle &, PatternTermPtr &)

void	init (void)

void	common_init (void)

void	setup_components (void)
	The second half of the common initialization sequence. More...

	PatternLink (Type, const HandleSeq &, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

Protected Member Functions inherited from opencog::Atom
	Atom (Type t, TruthValuePtr tv=TruthValue::DEFAULT_TV(), AttentionValuePtr av=AttentionValue::DEFAULT_AV())

void	keep_incoming_set ()

void	drop_incoming_set ()

void	insert_atom (LinkPtr)
	Add an atom to the incoming set. More...

void	remove_atom (LinkPtr)
	Remove an atom from the incoming set. More...

Protected Attributes
Handle	_implicand
	The rewrite term. More...

Protected Attributes inherited from opencog::PatternLink
Handle	_body

Variables	_varlist

Pattern	_pat

HandleSeq	_fixed

size_t	_num_virts

HandleSeq	_virtual

size_t	_num_comps

std::vector< HandleSeq >	_components

std::vector< std::set< Handle > >	_component_vars

HandleSeq	_component_patterns

Protected Attributes inherited from opencog::Link
HandleSeq	_outgoing

Protected Attributes inherited from opencog::Atom
UUID	_uuid

AtomTable *	_atomTable

Type	_type

char	_flags

TruthValuePtr	_truthValue

AttentionValuePtr	_attentionValue

std::mutex	_mtx

InSetPtr	_incoming_set

Additional Inherited Members
Protected Types inherited from opencog::Atom
typedef std::shared_ptr< InSet >	InSetPtr

Static Protected Member Functions inherited from opencog::PatternLink
static void	prt (const Handle &h)

Detailed Description

Definition at line 33 of file BindLink.h.

Constructor & Destructor Documentation

BindLink::BindLink	(	Type	t,
		const HandleSeq &	hseq,
		TruthValuePtr	tv = `TruthValue::DEFAULT_TV()`,
		AttentionValuePtr	av = `AttentionValue::DEFAULT_AV()`
	)

protected

Definition at line 49 of file BindLink.cc.

References init().

BindLink::BindLink	(	const HandleSeq &	hseq,
		TruthValuePtr	tv = `TruthValue::DEFAULT_TV()`,
		AttentionValuePtr	av = `AttentionValue::DEFAULT_AV()`
	)

Definition at line 42 of file BindLink.cc.

References init().

BindLink::BindLink ( Link & l )

Definition at line 56 of file BindLink.cc.

References opencog::classserver(), opencog::Atom::getType(), opencog::ClassServer::getTypeName(), init(), and python.undocumented.blocksworld::t.

Member Function Documentation

void BindLink::extract_variables ( const HandleSeq & oset )

protected

Find and unpack variable declarations, if any; otherwise, just find all free variables.

On top of that initialize _body and _implicand with the clauses and the rewrite rule.

Definition at line 78 of file BindLink.cc.

References opencog::PatternLink::_body, _implicand, opencog::PatternLink::_varlist, opencog::FreeLink::get_vars(), and opencog::PatternLink::init_scoped_variables().

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const Handle& opencog::BindLink::get_implicand ( void )

inline

Definition at line 58 of file BindLink.h.

References _implicand.

bool BindLink::imply	(	PatternMatchCallback &	pmc,
		bool	check_conn = `true`
	)

Ground (solve) a pattern; perform unification. That is, find one or more groundings for the variables occuring in a collection of clauses (a hypergraph). The hypergraph can be thought of as a a 'predicate' which becomes 'true' when a grounding exists.

The predicate is defined in terms of two hypergraphs: one is a hypergraph defining a pattern to be grounded, and the other is a list of bound variables in the first.

The bound variables are, by convention, VariableNodes. (The code in the pattern match engine doesn't care whether the variable nodes are actually of type VariableNode, and so can work with variables that are any kind of node. However, the default callbacks do check for this type. Thus, the restriction, by convention, that the variables must be of type VariableNode.) The list of bound variables is then assumed to be listed using the ListLink type. So, for example:

ListLink VariableNode "variable 1" VariableNode "another variable"

The pattern hypergraph is assumed to be a list of "clauses", where each "clause" should be thought of as the tree defined by the outgoing sets in it. The below assumes that the list of clauses is specified by means of an AndLink, so, for example:

AndLink
   SomeLink ....
   SomeOtherLink ...

The clauses are assumed to be connected by variables, i.e. each clause has a variable that also appears in some other clause. Even more strongly, it is assumed that there is just one connected component; the code below throws an error if there is more than one connected component. The reason for this is to avoid unintended combinatoric explosions: the grounding of any one (connected) component is completely independent of the grounding of any other component. So, if there are two components, and one has N groundings and the other has M groundings, then the two together trivially have MxN groundings. Its worse if there are 4, 4... components. Rather than stupidly reporting a result MxNx... times, we just throw an error, and let the user decide what to do.

The grounding proceeds by requiring each clause to match some part of the atomspace (i.e. of the universe of hypergraphs stored in the atomspace). When a solution is found, PatternMatchCallback::solution method is called, and it is passed two maps: one mapping the bound variables to their groundings, and the other mapping the pattern clauses to their corresponding grounded clauses.

Note: the pattern matcher itself doesn't use the atomspace, or care if the groundings live in the atomspace; it can search anything. However, the default callbacks do use the atomspace to find an initial starting point for the search, and thus the search defacto happens on the atomspace. This restriction can be lifted by tweaking the callback that initially launches the search.

At this time, the list of clauses is understood to be a single disjunct; that is, all of the clauses must be simultaneously satisfied. A future extension could allow the use of MatchOrLinks to support multiple exclusive disjuncts. See the README for more info. Evaluate a BindLink

Given a BindLink containing variable declarations, a predicate and an implicand, this method will "evaluate" the implication, matching the predicate, and creating a grounded implicand, assuming the predicate can be satisfied. Thus, for example, given the structure

BindLink ListLink VariableNode "$var0" VariableNode "$var1" AndList etc ...

Evaluation proceeds as decribed in the "do_imply()" function below. The whole point of the BindLink is to do nothing more than to indicate the bindings of the variables, and (optionally) limit the types of acceptable groundings for the variables.

Definition at line 315 of file PatternMatch.cc.

References opencog::PatternLink::_components, opencog::PatternLink::_virtual, and opencog::PatternLink::satisfy().

void BindLink::init ( void )

protected

Definition at line 33 of file BindLink.cc.

References opencog::PatternLink::_body, opencog::Link::_outgoing, opencog::PatternLink::_pat, opencog::PatternLink::common_init(), extract_variables(), opencog::Pattern::redex_name, opencog::PatternLink::setup_components(), and opencog::PatternLink::unbundle_clauses().

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Member Data Documentation

Handle opencog::BindLink::_implicand

protected

The rewrite term.

Definition at line 39 of file BindLink.h.

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

opencog/atoms/bind/BindLink.h
opencog/atoms/bind/BindLink.cc
opencog/query/PatternMatch.cc

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation