Revert "Merge pull request opencog#2500 from linas/anchor-link"

Linking results to the AnchorNode idea now seems like a bad idea,
in retrospect.  The ideas in opencog#2911 seem superior. So trash the
AnchorNode support in the query subsystem.

FWIW, if this kind of thing was wanted, a better solution would
be a new kind of Value, that dequeued from a QueueValue, and
plopped the results onto an AnchorNode. ***This*** is the real
reason for stripping away this code: its not generic enough.

This reverts commit 46dea8e, reversing
changes made to 5ec84bb.

examples/pattern-matcher/README.md

@@ -84,7 +84,6 @@ Basic Examples
 The first five examples provide a basic introduction to basic
 pattern matching.
 
-* `anchor.scm`       -- Obtaining results incrementally.
 * `satisfaction.scm` -- Determining satisfiability of a query.
 * `unify.scm`        -- Basic term unification.
 * `glob.scm`         -- Matching multiple atoms at once.

opencog/atoms/core/Variables.cc

@@ -354,7 +354,7 @@ static const GlobInterval& default_interval(Type t)
 			 var_def_interval;
 }
 
-const GlobInterval Variables::get_interval(const Handle& var) const
+const GlobInterval& Variables::get_interval(const Handle& var) const
 {
 	const auto& decl = _typemap.find(var);
 
@@ -668,10 +668,34 @@ Handle Variables::get_vardecl() const
 
 	if (_ordered)
 		return HandleCast(createVariableList(std::move(vardecls)));
-
 	return HandleCast(createVariableSet(std::move(vardecls)));
 }
 
+void Variables::validate_vardecl(const HandleSeq& oset)
+{
+	for (const Handle& h: oset)
+	{
+		Type t = h->get_type();
+		if (VARIABLE_NODE == t or GLOB_NODE == t)
+		{
+			varset.insert(h);
+			varseq.emplace_back(h);
+		}
+		else if (TYPED_VARIABLE_LINK == t)
+		{
+			get_vartype(h);
+		}
+		else
+		{
+			throw InvalidParamException(TRACE_INFO,
+				"Expected a VariableNode or a TypedVariableLink, got: %s"
+				"\nVariableList is %s",
+					nameserver().getTypeName(t).c_str(),
+					to_string().c_str());
+		}
+	}
+}
+
 /* ================================================================= */
 
 std::string Variables::to_string(const std::string& indent) const

opencog/atoms/core/Variables.h

@@ -68,8 +68,13 @@ struct Variables : public FreeVariables
 	/// _typemap holds back-ponters to TypedVariableLinkPtrs
 	VariableTypeMap _typemap;
 
+<<<<<<< HEAD
 	/// Anchor, if present, else undefined.
 	Handle _anchor;
+=======
+	// See VariableList.cc for comments
+	void get_vartype(const Handle&);
+>>>>>>> parent of 46dea8ea1 (Merge pull request #2500 from linas/anchor-link)
 
 	// Validate the variable decls
 	void validate_vardecl(const Handle&);

opencog/atoms/pattern/BindLink.cc

@@ -69,16 +69,6 @@ ValuePtr BindLink::execute(AtomSpace* as, bool silent)
 	OC_ASSERT(qv->is_closed(), "Unexpected queue state!");
 	HandleSeq rslt(qv->to_handle_seq());
 
-	// If there is an anchor, then attach results to the anchor.
-	// Otherwise, create a SetLink and return that.
-	if (_variables._anchor and as)
-	{
-		for (const Handle& h: rslt)
-			as->add_link(MEMBER_LINK, h, _variables._anchor);
-
-		return _variables._anchor;
-	}
-
 	// The result_set contains a list of the grounded expressions.
 	// (The order of the list has no significance, so it's really a set.)
 	// Put the set into a SetLink, cache it, and return that.

opencog/atoms/pattern/DualLink.cc

@@ -79,21 +79,6 @@ ValuePtr DualLink::execute(AtomSpace* as, bool silent)
 	if (nullptr == as) as = _atom_space;
 	Recognizer reco(as);
 	reco.satisfy(PatternLinkCast(get_handle()));
-
-	// If there is an anchor, then attach results to the anchor.
-	// Otherwise, create a SetLink and return that.
-	// XXX FIXME ... at this time, there is no documented way of
-	// squeezing an AnchorLink into a DualLink.  So the below
-	// if-statement is never taken. Some additional design work
-	// is needed.
-	if (_variables._anchor and as)
-	{
-		for (const Handle& h : reco._rules)
-			as->add_link(MEMBER_LINK, h, _variables._anchor);
-
-		return _variables._anchor;
-	}
-
 	return as->add_atom(createUnorderedLink(reco._rules, SET_LINK));
 }
 

opencog/atoms/pattern/GetLink.cc

@@ -53,16 +53,6 @@ ValuePtr GetLink::execute(AtomSpace* as, bool silent)
 	OC_ASSERT(qv->is_closed(), "Unexpected queue state!");
 	HandleSet hs(qv->to_handle_set());
 
-	// If there is an anchor, then attach results to the anchor.
-	// Otherwise, create a SetLink and return that.
-	if (_variables._anchor and as)
-	{
-		for (const Handle& h : hs)
-			as->add_link(MEMBER_LINK, h, _variables._anchor);
-
-		return _variables._anchor;
-	}
-
 	// Create the satisfying set, and cache it.
 	Handle satset(createUnorderedLink(std::move(hs), SET_LINK));
 

opencog/atoms/pattern/SatisfactionLink.cc

@@ -52,12 +52,6 @@ TruthValuePtr SatisfactionLink::evaluate(AtomSpace* as, bool silent)
 	Satisfier sater(as);
 	sater.satisfy(PatternLinkCast(get_handle()));
 
-	// If there is an anchor, then attach results to the anchor.
-	if (_variables._anchor and as)
-	{
-		as->add_link(MEMBER_LINK, sater._ground, _variables._anchor);
-	}
-
 	return sater._result;
 }
 

tests/query/CMakeLists.txt

@@ -59,7 +59,6 @@ ADD_CXXTEST(RecognizerUTest)
 ADD_CXXTEST(ArcanaUTest)
 ADD_CXXTEST(SubstitutionUTest)
 ADD_CXXTEST(GetLinkUTest)
-ADD_CXXTEST(AnchorUTest)
 ADD_CXXTEST(NotLinkUTest)
 ADD_CXXTEST(GetStateUTest)
 ADD_CXXTEST(ClassicalBooleanUTest)
@@ -150,7 +149,6 @@ TARGET_LINK_LIBRARIES(SparseUTest
 )
 
 # -------------------------------------------------------------
-
 # Run only the tests in this subdirectory
 ADD_CUSTOM_TARGET (qtest
 	DEPENDS tests