Evolog Modules: Permit external atom interpretations to return Set<List<Term>> rather than just Set<List<ConstantTerm>> so we can have module interpretations returning function terms

Author: madmike200590

alpha-api/src/main/java/at/ac/tuwien/kr/alpha/api/common/fixedinterpretations/PredicateInterpretation.java

@@ -37,10 +37,11 @@
 
 @FunctionalInterface
 public interface PredicateInterpretation {
-	Set<List<ConstantTerm<?>>> TRUE = singleton(emptyList());
-	Set<List<ConstantTerm<?>>> FALSE = emptySet();
+
+	Set<List<Term>> TRUE = singleton(emptyList());
+	Set<List<Term>> FALSE = emptySet();
 
 	String EVALUATE_RETURN_TYPE_NAME_PREFIX = Set.class.getName() + "<" + List.class.getName() + "<" + ConstantTerm.class.getName();
 
-	Set<List<ConstantTerm<?>>> evaluate(List<Term> terms);
+	Set<List<Term>> evaluate(List<Term> terms);
 }

alpha-commons/src/main/java/at/ac/tuwien/kr/alpha/commons/externals/BindingMethodPredicateInterpretation.java

@@ -52,7 +52,7 @@ public BindingMethodPredicateInterpretation(Method method) {
 
 	@Override
 	@SuppressWarnings("unchecked")
-	public Set<List<ConstantTerm<?>>> evaluate(List<Term> terms) {
+	public Set<List<Term>> evaluate(List<Term> terms) {
 		if (terms.size() != method.getParameterCount()) {
 			throw new IllegalArgumentException(
 					"Parameter count mismatch when calling " + method.getName() + ". " +
@@ -90,7 +90,7 @@ public Set<List<ConstantTerm<?>>> evaluate(List<Term> terms) {
 		}
 
 		try {
-			return (Set<List<ConstantTerm<?>>>) method.invoke(null, arguments);
+			return (Set<List<Term>>) method.invoke(null, arguments);
 		} catch (IllegalAccessException | InvocationTargetException ex) {
 			throw new RuntimeException("Error invoking method " + method + "with args [" + StringUtils.join(arguments) + "], expection is: " + ex.getMessage());
 		}

alpha-commons/src/main/java/at/ac/tuwien/kr/alpha/commons/externals/Externals.java

@@ -29,6 +29,7 @@
 import at.ac.tuwien.kr.alpha.api.externals.Predicate;
 import at.ac.tuwien.kr.alpha.api.programs.atoms.Atom;
 import at.ac.tuwien.kr.alpha.api.programs.terms.ConstantTerm;
+import at.ac.tuwien.kr.alpha.api.programs.terms.Term;
 import at.ac.tuwien.kr.alpha.commons.Predicates;
 import at.ac.tuwien.kr.alpha.commons.programs.atoms.Atoms;
 import at.ac.tuwien.kr.alpha.commons.programs.terms.Terms;
@@ -114,7 +115,7 @@ public static <T, U> PredicateInterpretation processPredicate(java.util.function
 		return new BinaryPredicateInterpretation<>(predicate);
 	}
 
-	public static PredicateInterpretation processPredicate(java.util.function.Supplier<Set<List<ConstantTerm<?>>>> supplier) {
+	public static PredicateInterpretation processPredicate(java.util.function.Supplier<Set<List<Term>>> supplier) {
 		return new SuppliedPredicateInterpretation(supplier);
 	}
 

alpha-commons/src/main/java/at/ac/tuwien/kr/alpha/commons/externals/NonBindingPredicateInterpretation.java

@@ -51,7 +51,7 @@ public NonBindingPredicateInterpretation() {
 	}
 
 	@Override
-	public Set<List<ConstantTerm<?>>> evaluate(List<Term> terms) {
+	public Set<List<Term>> evaluate(List<Term> terms) {
 		if (terms.size() != arity) {
 			throw new IllegalArgumentException("Exactly " + arity + " term(s) required.");
 		}

alpha-commons/src/main/java/at/ac/tuwien/kr/alpha/commons/externals/PredicateInterpretationImpl.java

@@ -28,22 +28,21 @@
 package at.ac.tuwien.kr.alpha.commons.externals;
 
 import at.ac.tuwien.kr.alpha.api.common.fixedinterpretations.BindingPredicateInterpretation;
-import at.ac.tuwien.kr.alpha.api.programs.terms.ConstantTerm;
 import at.ac.tuwien.kr.alpha.api.programs.terms.Term;
 
 import java.util.List;
 import java.util.Set;
 import java.util.function.Supplier;
 
 public class SuppliedPredicateInterpretation implements BindingPredicateInterpretation {
-	private final Supplier<Set<List<ConstantTerm<?>>>> supplier;
+	private final Supplier<Set<List<Term>>> supplier;
 
-	public SuppliedPredicateInterpretation(Supplier<Set<List<ConstantTerm<?>>>> supplier) {
+	public SuppliedPredicateInterpretation(Supplier<Set<List<Term>>> supplier) {
 		this.supplier = supplier;
 	}
 
 	@Override
-	public Set<List<ConstantTerm<?>>> evaluate(List<Term> terms) {
+	public Set<List<Term>> evaluate(List<Term> terms) {
 		if (!terms.isEmpty()) {
 			throw new IllegalArgumentException("Can only be used without any arguments.");
 		}

alpha-commons/src/main/java/at/ac/tuwien/kr/alpha/commons/externals/SuppliedPredicateInterpretation.java

@@ -127,7 +127,8 @@ public List<Substitution> getSatisfyingSubstitutions(Substitution partialSubstit
 		for (Term t : input) {
 			substitutes.add(t.substitute(partialSubstitution));
 		}
-		Set<List<ConstantTerm<?>>> results = getAtom().getInterpretation().evaluate(substitutes);
+		Set<List<Term>> results = getAtom().getInterpretation().evaluate(substitutes);
+		// TODO verify all results are ground
 		if (results == null) {
 			throw new NullPointerException("Predicate " + getPredicate().getName() + " returned null. It must return a Set.");
 		}
@@ -160,10 +161,10 @@ public List<Substitution> getSatisfyingSubstitutions(Substitution partialSubstit
 	 * @return true iff no list in externalMethodResult equals the external atom's output term
 	 *         list as substituted by the grounder, false otherwise
 	 */
-	private boolean isNegatedLiteralSatisfied(Set<List<ConstantTerm<?>>> externalMethodResult) {
+	private boolean isNegatedLiteralSatisfied(Set<List<Term>> externalMethodResult) {
 		List<Term> externalAtomOutTerms = this.getAtom().getOutput();
 		boolean outputMatches;
-		for (List<ConstantTerm<?>> resultTerms : externalMethodResult) {
+		for (List<Term> resultTerms : externalMethodResult) {
 			outputMatches = true;
 			for (int i = 0; i < externalAtomOutTerms.size(); i++) {
 				if (!resultTerms.get(i).equals(externalAtomOutTerms.get(i))) {
@@ -182,10 +183,10 @@ private boolean isNegatedLiteralSatisfied(Set<List<ConstantTerm<?>>> externalMet
 		return true;
 	}
 
-	private List<Substitution> buildSubstitutionsForOutputs(Substitution partialSubstitution, Set<List<ConstantTerm<?>>> outputs) {
+	private List<Substitution> buildSubstitutionsForOutputs(Substitution partialSubstitution, Set<List<Term>> outputs) {
 		List<Substitution> retVal = new ArrayList<>();
 		List<Term> externalAtomOutputTerms = this.getAtom().getOutput();
-		for (List<ConstantTerm<?>> bindings : outputs) {
+		for (List<Term> bindings : outputs) {
 			if (bindings.size() < externalAtomOutputTerms.size()) {
 				throw new RuntimeException(
 						"Predicate " + getPredicate().getName() + " returned " + bindings.size() + " terms when at least " + externalAtomOutputTerms.size()