forked from JavaTX/JavaCompilerCore
Parallelisierung mit Fork-Join Pool
This commit is contained in:
Florian Steurer
parent
8fa8fc8758
commit
7d75f18319
@ -1,605 +1,16 @@
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package de.dhbwstuttgart.typeinference.unify;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Collection;
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import java.util.HashSet;
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import java.util.LinkedHashSet;
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import java.util.LinkedList;
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import java.util.List;
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import java.util.Map.Entry;
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import java.util.Optional;
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import java.util.Set;
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import java.util.stream.Collectors;
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import java.util.concurrent.ForkJoinPool;
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import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
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import de.dhbwstuttgart.typeinference.unify.interfaces.IRuleSet;
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import de.dhbwstuttgart.typeinference.unify.interfaces.ISetOperations;
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import de.dhbwstuttgart.typeinference.unify.interfaces.IUnify;
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import de.dhbwstuttgart.typeinference.unify.model.ExtendsType;
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import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
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import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
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import de.dhbwstuttgart.typeinference.unify.model.SuperType;
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import de.dhbwstuttgart.typeinference.unify.model.TypeParams;
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import de.dhbwstuttgart.typeinference.unify.model.Unifier;
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import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
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import de.dhbwstuttgart.typeinference.unify.model.UnifyType;
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/**
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* Implementation of the type unification algorithm
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* @author Florian Steurer
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*/
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public class TypeUnify {
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/**
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* The implementation of setOps that will be used during the unification
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*/
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protected ISetOperations setOps = new GuavaSetOperations();
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/**
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* The implementation of the standard unify that will be used during the unification
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*/
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protected IUnify stdUnify = new MartelliMontanariUnify();
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/**
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* The implementation of the rules that will be used during the unification.
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*/
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protected IRuleSet rules = new RuleSet();
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/**
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* Computes all principal type unifiers for a set of constraints.
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* @param eq The set of constraints
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* @param fc The finite closure
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* @return The set of all principal type unifiers
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*/
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public Set<Set<UnifyPair>> unify(Set<UnifyPair> eq, IFiniteClosure fc) {
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/*
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* Step 1: Repeated application of reduce, adapt, erase, swap
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*/
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Set<UnifyPair> eq0 = applyTypeUnificationRules(eq, fc);
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/*
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* Step 2 and 3: Create a subset eq1s of pairs where both sides are TPH and eq2s of the other pairs
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*/
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Set<UnifyPair> eq1s = new HashSet<>();
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Set<UnifyPair> eq2s = new HashSet<>();
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splitEq(eq0, eq1s, eq2s);
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/*
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* Step 4: Create possible typings
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*
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* "Manche Autoren identifizieren die Paare (a, (b,c)) und ((a,b),c)
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* mit dem geordneten Tripel (a,b,c), wodurch das kartesische Produkt auch assoziativ wird." - Wikipedia
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*/
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// There are up to 10 toplevel set. 8 of 10 are the result of the
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// cartesian product of the sets created by pattern matching.
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List<Set<Set<UnifyPair>>> topLevelSets = new ArrayList<>();
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if(eq1s.size() != 0) { // Do not add empty sets or the cartesian product will always be empty.
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Set<Set<UnifyPair>> wrap = new HashSet<>();
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wrap.add(eq1s);
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topLevelSets.add(wrap); // Add Eq1'
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}
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// Add the set of [a =. Theta | (a=. Theta) in Eq2']
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Set<UnifyPair> bufferSet = eq2s.stream()
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.filter(x -> x.getPairOp() == PairOperator.EQUALSDOT && x.getLhsType() instanceof PlaceholderType)
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.collect(Collectors.toSet());
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if(bufferSet.size() != 0) { // Do not add empty sets or the cartesian product will always be empty.
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Set<Set<UnifyPair>> wrap = new HashSet<>();
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wrap.add(bufferSet);
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topLevelSets.add(wrap);
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eq2s.removeAll(bufferSet);
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}
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// Sets that originate from pair pattern matching
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// Sets of the "second level"
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Set<UnifyPair> undefinedPairs = new HashSet<>();
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Set<Set<Set<Set<UnifyPair>>>> secondLevelSets = calculatePairSets(eq2s, fc, undefinedPairs);
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// If pairs occured that did not match one of the cartesian product cases,
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// those pairs are contradictory and the unification is impossible.
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if(!undefinedPairs.isEmpty())
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return new HashSet<>();
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/* Up to here, no cartesian products are calculated.
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* filters for pairs and sets can be applied here */
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// Sub cartesian products of the second level (pattern matched) sets
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// "the big (x)"
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// TODO Optimierungsmöglichkeit: Parallelisierung der Schleife möglich (scheint sich nicht zu lohnen)
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for(Set<Set<Set<UnifyPair>>> secondLevelSet : secondLevelSets) {
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List<Set<Set<UnifyPair>>> secondLevelSetList = new ArrayList<>(secondLevelSet);
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Set<List<Set<UnifyPair>>> cartResult = setOps.cartesianProduct(secondLevelSetList);
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// Flatten and add to top level sets
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Set<Set<UnifyPair>> flat = new HashSet<>();
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for(List<Set<UnifyPair>> s : cartResult) {
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Set<UnifyPair> flat1 = new HashSet<>();
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for(Set<UnifyPair> s1 : s)
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flat1.addAll(s1);
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flat.add(flat1);
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}
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topLevelSets.add(flat);
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}
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// Cartesian product over all (up to 10) top level sets
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Set<Set<Set<UnifyPair>>> eqPrimeSet = setOps.cartesianProduct(topLevelSets)
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.stream().map(x -> new HashSet<>(x))
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.collect(Collectors.toCollection(HashSet::new));
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//System.out.println(result);
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Set<Set<UnifyPair>> eqPrimePrimeSet = new HashSet<>();
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// TODO parallelisierung möglich (scheint sich nicht zu lohnen)
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/*
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* Die Parallelisierung über parallelStream() ist langsamer als die serielle Ausführung,
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* vermutlich wird zuviel thread-overhead erzeugt.
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* Vermutlich ist die beste Lösung hier ein Fork-Join-Framework.
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*/
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for(Set<Set<UnifyPair>> setToFlatten : eqPrimeSet) {
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// Flatten the cartesian product
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Set<UnifyPair> eqPrime = new HashSet<>();
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setToFlatten.stream().forEach(x -> eqPrime.addAll(x));
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/*
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* Step 5: Substitution
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*/
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Optional<Set<UnifyPair>> eqPrimePrime = rules.subst(eqPrime);
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/*
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* Step 6 a) Restart for pairs where subst was applied
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* b) Build the union over everything
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*/
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if (eqPrime.equals(eq))
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eqPrimePrimeSet.add(eqPrime);
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else if(eqPrimePrime.isPresent())
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eqPrimePrimeSet.addAll(this.unify(eqPrimePrime.get(), fc));
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else
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eqPrimePrimeSet.addAll(this.unify(eqPrime, fc));
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}
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/*
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* Step 7: Filter empty sets;
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*/
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return eqPrimePrimeSet.stream().filter(x -> isSolvedForm(x)).collect(Collectors.toCollection(HashSet::new));
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}
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/**
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* Checks whether a set of pairs is in solved form.
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* @param eqPrimePrime The set of pair
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* @return True if in solved form, false otherwise.
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*/
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protected boolean isSolvedForm(Set<UnifyPair> eqPrimePrime) {
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for(UnifyPair pair : eqPrimePrime) {
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UnifyType lhsType = pair.getLhsType();
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UnifyType rhsType = pair.getRhsType();
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if(!(lhsType instanceof PlaceholderType))
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return false;
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// If operator is not equals, both sides must be placeholders
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if(pair.getPairOp() != PairOperator.EQUALSDOT && !(rhsType instanceof PlaceholderType))
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return false;
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}
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return true;
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}
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/**
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* Repeatedly applies type unification rules to a set of equations.
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* This is step one of the unification algorithm.
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* @return The set of pairs that results from repeated application of the inference rules.
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*/
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protected Set<UnifyPair> applyTypeUnificationRules(Set<UnifyPair> eq, IFiniteClosure fc) {
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/*
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* Rule Application Strategy:
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*
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* 1. Swap all pairs and erase all erasable pairs
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* 2. Apply all possible rules to a single pair, then move it to the result set.
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* Iterating over pairs first, then iterating over rules prevents the application
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* of rules to a "finished" pair over and over.
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* 2.1 Apply all rules repeatedly except for erase rules. If
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* the application of a rule creates new pairs, check immediately
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* against the erase rules.
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*/
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LinkedHashSet<UnifyPair> targetSet = new LinkedHashSet<UnifyPair>();
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LinkedList<UnifyPair> eqQueue = new LinkedList<>();
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/*
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* Swap all pairs and erase all erasable pairs
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*/
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eq.forEach(x -> swapAddOrErase(x, fc, eqQueue));
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/*
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* Apply rules until the queue is empty
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*/
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while(!eqQueue.isEmpty()) {
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UnifyPair pair = eqQueue.pollFirst();
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// ReduceUp, ReduceLow, ReduceUpLow
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Optional<UnifyPair> opt = rules.reduceUpLow(pair);
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opt = opt.isPresent() ? opt : rules.reduceLow(pair);
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opt = opt.isPresent() ? opt : rules.reduceUp(pair);
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opt = opt.isPresent() ? opt : rules.reduceWildcardLow(pair);
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opt = opt.isPresent() ? opt : rules.reduceWildcardLowRight(pair);
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opt = opt.isPresent() ? opt : rules.reduceWildcardUp(pair);
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opt = opt.isPresent() ? opt : rules.reduceWildcardUpRight(pair);
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opt = opt.isPresent() ? opt : rules.reduceWildcardLowUp(pair);
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opt = opt.isPresent() ? opt : rules.reduceWildcardUpLow(pair);
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opt = opt.isPresent() ? opt : rules.reduceWildcardLeft(pair);
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// Reduce TPH
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opt = opt.isPresent() ? opt : rules.reduceTph(pair);
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// One of the rules has been applied
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if(opt.isPresent()) {
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swapAddOrErase(opt.get(), fc, eqQueue);
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continue;
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}
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// Reduce1, Reduce2, ReduceExt, ReduceSup, ReduceEq
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Optional<Set<UnifyPair>> optSet = rules.reduce1(pair, fc);
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optSet = optSet.isPresent() ? optSet : rules.reduce2(pair);
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optSet = optSet.isPresent() ? optSet : rules.reduceExt(pair, fc);
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optSet = optSet.isPresent() ? optSet : rules.reduceSup(pair, fc);
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optSet = optSet.isPresent() ? optSet : rules.reduceEq(pair);
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// ReduceTphExt, ReduceTphSup
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optSet = optSet.isPresent() ? optSet : rules.reduceTphExt(pair);
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optSet = optSet.isPresent() ? optSet : rules.reduceTphSup(pair);
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// One of the rules has been applied
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if(optSet.isPresent()) {
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optSet.get().forEach(x -> swapAddOrErase(x, fc, eqQueue));
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continue;
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}
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// Adapt, AdaptExt, AdaptSup
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opt = rules.adapt(pair, fc);
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opt = opt.isPresent() ? opt : rules.adaptExt(pair, fc);
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opt = opt.isPresent() ? opt : rules.adaptSup(pair, fc);
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// One of the rules has been applied
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if(opt.isPresent()) {
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swapAddOrErase(opt.get(), fc, eqQueue);
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continue;
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}
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// None of the rules has been applied
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targetSet.add(pair);
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}
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return targetSet;
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}
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/**
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* Applies the rule swap to a pair if possible. Then adds the pair to the set if no erase rule applies.
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* If an erase rule applies, the pair is not added (erased).
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* @param pair The pair to swap and add or erase.
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* @param collection The collection to which the pairs are added.
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*/
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protected void swapAddOrErase(UnifyPair pair, IFiniteClosure fc, Collection<UnifyPair> collection) {
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Optional<UnifyPair> opt = rules.swap(pair);
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UnifyPair pair2 = opt.isPresent() ? opt.get() : pair;
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if(rules.erase1(pair2, fc) || rules.erase3(pair2) || rules.erase2(pair2, fc))
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return;
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collection.add(pair2);
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}
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/**
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* Splits the equation eq into a set eq1s where both terms are type variables,
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* and a set eq2s where one of both terms is not a type variable.
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* @param eq Set of pairs to be splitted.
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* @param eq1s Subset of eq where both terms are type variables.
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* @param eq2s eq/eq1s.
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*/
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protected void splitEq(Set<UnifyPair> eq, Set<UnifyPair> eq1s, Set<UnifyPair> eq2s) {
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for(UnifyPair pair : eq)
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if(pair.getLhsType() instanceof PlaceholderType && pair.getRhsType() instanceof PlaceholderType)
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eq1s.add(pair);
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else
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eq2s.add(pair);
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}
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/**
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* Creates sets of pairs specified in the fourth step. Does not calculate cartesian products.
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* @param undefined All pairs that did not match one of the 8 cases are added to this set.
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* @return The set of the eight cases (without empty sets). Each case is a set, containing sets generated
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* from the pairs that matched the case. Each generated set contains singleton sets or sets with few elements
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* (as in case 1 where sigma is added to the innermost set).
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*/
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protected Set<Set<Set<Set<UnifyPair>>>> calculatePairSets(Set<UnifyPair> eq2s, IFiniteClosure fc, Set<UnifyPair> undefined) {
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List<Set<Set<Set<UnifyPair>>>> result = new ArrayList<>(8);
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// Init all 8 cases
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for(int i = 0; i < 8; i++)
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result.add(new HashSet<>());
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for(UnifyPair pair : eq2s) {
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PairOperator pairOp = pair.getPairOp();
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UnifyType lhsType = pair.getLhsType();
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UnifyType rhsType = pair.getRhsType();
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// Case 1: (a <. Theta')
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if(pairOp == PairOperator.SMALLERDOT && lhsType instanceof PlaceholderType)
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result.get(0).add(unifyCase1((PlaceholderType) pair.getLhsType(), pair.getRhsType(), fc));
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// Case 2: (a <.? ? ext Theta')
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else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof PlaceholderType && rhsType instanceof ExtendsType)
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result.get(1).add(unifyCase2((PlaceholderType) pair.getLhsType(), (ExtendsType) pair.getRhsType(), fc));
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// Case 3: (a <.? ? sup Theta')
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else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof PlaceholderType && rhsType instanceof SuperType)
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result.get(2).add(unifyCase3((PlaceholderType) lhsType, (SuperType) rhsType, fc));
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// Case 4 was replaced by an inference rule
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// Case 4: (a <.? Theta')
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//else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof PlaceholderType)
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// result.get(3).add(unifyCase4((PlaceholderType) lhsType, rhsType, fc));
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// Case 5: (Theta <. a)
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else if(pairOp == PairOperator.SMALLERDOT && rhsType instanceof PlaceholderType)
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result.get(4).add(unifyCase5(lhsType, (PlaceholderType) rhsType, fc));
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// Case 6 was replaced by an inference rule.
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// Case 6: (? ext Theta <.? a)
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//else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof ExtendsType && rhsType instanceof PlaceholderType)
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// result.get(5).add(unifyCase6((ExtendsType) lhsType, (PlaceholderType) rhsType, fc));
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// Case 7 was replaced by an inference rule
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// Case 7: (? sup Theta <.? a)
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//else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof SuperType && rhsType instanceof PlaceholderType)
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// result.get(6).add(unifyCase7((SuperType) lhsType, (PlaceholderType) rhsType, fc));
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// Case 8: (Theta <.? a)
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else if(pairOp == PairOperator.SMALLERDOTWC && rhsType instanceof PlaceholderType)
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result.get(7).add(unifyCase8(lhsType, (PlaceholderType) rhsType, fc));
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// Case unknown: If a pair fits no other case, then the type unification has failed.
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// Through application of the rules, every pair should have one of the above forms.
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// Pairs that do not have one of the aboves form are contradictory.
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else
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undefined.add(pair);
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}
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// Filter empty sets or sets that only contain an empty set.
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return result.stream().map(x -> x.stream().filter(y -> y.size() > 0).collect(Collectors.toCollection(HashSet::new)))
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.filter(x -> x.size() > 0).collect(Collectors.toCollection(HashSet::new));
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}
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/**
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* Cartesian product Case 1: (a <. Theta')
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*/
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protected Set<Set<UnifyPair>> unifyCase1(PlaceholderType a, UnifyType thetaPrime, IFiniteClosure fc) {
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Set<Set<UnifyPair>> result = new HashSet<>();
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Set<UnifyType> cs = fc.getAllTypesByName(thetaPrime.getName());
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cs.add(thetaPrime);
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for(UnifyType c : cs) {
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Set<UnifyType> thetaQs = fc.getChildren(c).stream().collect(Collectors.toCollection(HashSet::new));
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thetaQs.add(thetaPrime);
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Set<UnifyType> thetaQPrimes = new HashSet<>();
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TypeParams cParams = c.getTypeParams();
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if(cParams.size() == 0)
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thetaQPrimes.add(c);
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else {
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ArrayList<Set<UnifyType>> candidateParams = new ArrayList<>();
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for(UnifyType param : cParams)
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candidateParams.add(fc.grArg(param));
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for(TypeParams tp : permuteParams(candidateParams))
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thetaQPrimes.add(c.setTypeParams(tp));
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}
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for(UnifyType tqp : thetaQPrimes) {
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Optional<Unifier> opt = stdUnify.unify(tqp, thetaPrime);
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if (!opt.isPresent())
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continue;
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Unifier unifier = opt.get();
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unifier.swapPlaceholderSubstitutions(thetaPrime.getTypeParams());
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Set<UnifyPair> substitutionSet = new HashSet<>();
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for (Entry<PlaceholderType, UnifyType> sigma : unifier)
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substitutionSet.add(new UnifyPair(sigma.getKey(), sigma.getValue(), PairOperator.EQUALSDOT));
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List<UnifyType> freshTphs = new ArrayList<>();
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||||
for (UnifyType tq : thetaQs) {
|
||||
Set<UnifyType> smaller = fc.smaller(unifier.apply(tq));
|
||||
for(UnifyType theta : smaller) {
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
|
||||
for(int i = 0; i < theta.getTypeParams().size(); i++) {
|
||||
if(freshTphs.size()-1 < i)
|
||||
freshTphs.add(PlaceholderType.freshPlaceholder());
|
||||
resultPrime.add(new UnifyPair(freshTphs.get(i), theta.getTypeParams().get(i), PairOperator.SMALLERDOTWC));
|
||||
}
|
||||
|
||||
UnifyType freshTheta = theta.setTypeParams(new TypeParams(freshTphs.toArray(new UnifyType[0])));
|
||||
resultPrime.add(new UnifyPair(a, freshTheta, PairOperator.EQUALSDOT));
|
||||
resultPrime.addAll(substitutionSet);
|
||||
result.add(resultPrime);
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 2: (a <.? ? ext Theta')
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase2(PlaceholderType a, ExtendsType extThetaPrime, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
|
||||
UnifyType aPrime = PlaceholderType.freshPlaceholder();
|
||||
UnifyType extAPrime = new ExtendsType(aPrime);
|
||||
UnifyType thetaPrime = extThetaPrime.getExtendedType();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, thetaPrime, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, extAPrime, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(aPrime, thetaPrime, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 3: (a <.? ? sup Theta')
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase3(PlaceholderType a, SuperType subThetaPrime, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
|
||||
UnifyType aPrime = PlaceholderType.freshPlaceholder();
|
||||
UnifyType supAPrime = new SuperType(aPrime);
|
||||
UnifyType thetaPrime = subThetaPrime.getSuperedType();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(thetaPrime, a, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, supAPrime, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(thetaPrime, aPrime, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 4: (a <.? Theta')
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase4(PlaceholderType a, UnifyType thetaPrime, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, thetaPrime, PairOperator.EQUALSDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 5: (Theta <. a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase5(UnifyType theta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
for(UnifyType thetaS : fc.greater(theta)) {
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
|
||||
UnifyType[] freshTphs = new UnifyType[thetaS.getTypeParams().size()];
|
||||
for(int i = 0; i < freshTphs.length; i++) {
|
||||
freshTphs[i] = PlaceholderType.freshPlaceholder();
|
||||
resultPrime.add(new UnifyPair(thetaS.getTypeParams().get(i), freshTphs[i], PairOperator.SMALLERDOTWC));
|
||||
}
|
||||
|
||||
resultPrime.add(new UnifyPair(a, thetaS.setTypeParams(new TypeParams(freshTphs)), PairOperator.EQUALSDOT));
|
||||
result.add(resultPrime);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 6: (? ext Theta <.? a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase6(ExtendsType extTheta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
UnifyType freshTph = PlaceholderType.freshPlaceholder();
|
||||
UnifyType extFreshTph = new ExtendsType(freshTph);
|
||||
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, extFreshTph, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(extTheta.getExtendedType(), freshTph, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 7: (? sup Theta <.? a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase7(SuperType supTheta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
|
||||
UnifyType aPrime = PlaceholderType.freshPlaceholder();
|
||||
UnifyType supAPrime = new SuperType(aPrime);
|
||||
UnifyType theta = supTheta.getSuperedType();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, supAPrime, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(aPrime, theta, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 8: (Theta <.? a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase8(UnifyType theta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
//for(UnifyType thetaS : fc.grArg(theta)) {
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, theta, PairOperator.EQUALSDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
UnifyType freshTph = PlaceholderType.freshPlaceholder();
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, new ExtendsType(freshTph), PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(theta, freshTph, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, new SuperType(freshTph), PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(freshTph, theta, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
//}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Takes a set of candidates for each position and computes all possible permutations.
|
||||
* @param candidates The length of the list determines the number of type params. Each set
|
||||
* contains the candidates for the corresponding position.
|
||||
*/
|
||||
protected Set<TypeParams> permuteParams(ArrayList<Set<UnifyType>> candidates) {
|
||||
Set<TypeParams> result = new HashSet<>();
|
||||
permuteParams(candidates, 0, result, new UnifyType[candidates.size()]);
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Takes a set of candidates for each position and computes all possible permutations.
|
||||
* @param candidates The length of the list determines the number of type params. Each set
|
||||
* contains the candidates for the corresponding position.
|
||||
* @param idx Idx for the current permutatiton.
|
||||
* @param result Set of all permutations found so far
|
||||
* @param current The permutation of type params that is currently explored
|
||||
*/
|
||||
private void permuteParams(ArrayList<Set<UnifyType>> candidates, int idx, Set<TypeParams> result, UnifyType[] current) {
|
||||
if(candidates.size() == idx) {
|
||||
result.add(new TypeParams(Arrays.copyOf(current, current.length)));
|
||||
return;
|
||||
}
|
||||
|
||||
Set<UnifyType> localCandidates = candidates.get(idx);
|
||||
|
||||
for(UnifyType t : localCandidates) {
|
||||
current[idx] = t;
|
||||
permuteParams(candidates, idx+1, result, current);
|
||||
}
|
||||
TypeUnifyTask unifyTask = new TypeUnifyTask(eq, fc);
|
||||
ForkJoinPool pool = new ForkJoinPool();
|
||||
pool.invoke(unifyTask);
|
||||
return unifyTask.join();
|
||||
}
|
||||
}
|
||||
|
||||
631
src/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
Normal file
631
src/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
Normal file
@ -0,0 +1,631 @@
|
||||
package de.dhbwstuttgart.typeinference.unify;
|
||||
|
||||
import java.util.ArrayList;
|
||||
import java.util.Arrays;
|
||||
import java.util.Collection;
|
||||
import java.util.HashSet;
|
||||
import java.util.LinkedHashSet;
|
||||
import java.util.LinkedList;
|
||||
import java.util.List;
|
||||
import java.util.Map.Entry;
|
||||
import java.util.Optional;
|
||||
import java.util.Set;
|
||||
import java.util.concurrent.RecursiveTask;
|
||||
import java.util.stream.Collectors;
|
||||
|
||||
import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
|
||||
import de.dhbwstuttgart.typeinference.unify.interfaces.IRuleSet;
|
||||
import de.dhbwstuttgart.typeinference.unify.interfaces.ISetOperations;
|
||||
import de.dhbwstuttgart.typeinference.unify.interfaces.IUnify;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.ExtendsType;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.PairOperator;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.PlaceholderType;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.SuperType;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.TypeParams;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.Unifier;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.UnifyPair;
|
||||
import de.dhbwstuttgart.typeinference.unify.model.UnifyType;
|
||||
|
||||
|
||||
/**
|
||||
* Implementation of the type unification algorithm
|
||||
* @author Florian Steurer
|
||||
*/
|
||||
public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>> {
|
||||
|
||||
/**
|
||||
* The implementation of setOps that will be used during the unification
|
||||
*/
|
||||
protected ISetOperations setOps = new GuavaSetOperations();
|
||||
|
||||
/**
|
||||
* The implementation of the standard unify that will be used during the unification
|
||||
*/
|
||||
protected IUnify stdUnify = new MartelliMontanariUnify();
|
||||
|
||||
/**
|
||||
* The implementation of the rules that will be used during the unification.
|
||||
*/
|
||||
protected IRuleSet rules = new RuleSet();
|
||||
|
||||
protected Set<UnifyPair> eq;
|
||||
|
||||
protected IFiniteClosure fc;
|
||||
|
||||
public TypeUnifyTask(Set<UnifyPair> eq, IFiniteClosure fc) {
|
||||
this.eq = eq;
|
||||
this.fc = fc;
|
||||
}
|
||||
|
||||
@Override
|
||||
protected Set<Set<UnifyPair>> compute() {
|
||||
return unify(eq, fc);
|
||||
}
|
||||
|
||||
/**
|
||||
* Computes all principal type unifiers for a set of constraints.
|
||||
* @param eq The set of constraints
|
||||
* @param fc The finite closure
|
||||
* @return The set of all principal type unifiers
|
||||
*/
|
||||
public Set<Set<UnifyPair>> unify(Set<UnifyPair> eq, IFiniteClosure fc) {
|
||||
/*
|
||||
* Step 1: Repeated application of reduce, adapt, erase, swap
|
||||
*/
|
||||
Set<UnifyPair> eq0 = applyTypeUnificationRules(eq, fc);
|
||||
|
||||
/*
|
||||
* Step 2 and 3: Create a subset eq1s of pairs where both sides are TPH and eq2s of the other pairs
|
||||
*/
|
||||
Set<UnifyPair> eq1s = new HashSet<>();
|
||||
Set<UnifyPair> eq2s = new HashSet<>();
|
||||
splitEq(eq0, eq1s, eq2s);
|
||||
|
||||
/*
|
||||
* Step 4: Create possible typings
|
||||
*
|
||||
* "Manche Autoren identifizieren die Paare (a, (b,c)) und ((a,b),c)
|
||||
* mit dem geordneten Tripel (a,b,c), wodurch das kartesische Produkt auch assoziativ wird." - Wikipedia
|
||||
*/
|
||||
|
||||
// There are up to 10 toplevel set. 8 of 10 are the result of the
|
||||
// cartesian product of the sets created by pattern matching.
|
||||
List<Set<Set<UnifyPair>>> topLevelSets = new ArrayList<>();
|
||||
|
||||
if(eq1s.size() != 0) { // Do not add empty sets or the cartesian product will always be empty.
|
||||
Set<Set<UnifyPair>> wrap = new HashSet<>();
|
||||
wrap.add(eq1s);
|
||||
topLevelSets.add(wrap); // Add Eq1'
|
||||
}
|
||||
|
||||
// Add the set of [a =. Theta | (a=. Theta) in Eq2']
|
||||
Set<UnifyPair> bufferSet = eq2s.stream()
|
||||
.filter(x -> x.getPairOp() == PairOperator.EQUALSDOT && x.getLhsType() instanceof PlaceholderType)
|
||||
.collect(Collectors.toSet());
|
||||
|
||||
if(bufferSet.size() != 0) { // Do not add empty sets or the cartesian product will always be empty.
|
||||
Set<Set<UnifyPair>> wrap = new HashSet<>();
|
||||
wrap.add(bufferSet);
|
||||
topLevelSets.add(wrap);
|
||||
eq2s.removeAll(bufferSet);
|
||||
}
|
||||
|
||||
// Sets that originate from pair pattern matching
|
||||
// Sets of the "second level"
|
||||
Set<UnifyPair> undefinedPairs = new HashSet<>();
|
||||
Set<Set<Set<Set<UnifyPair>>>> secondLevelSets = calculatePairSets(eq2s, fc, undefinedPairs);
|
||||
|
||||
// If pairs occured that did not match one of the cartesian product cases,
|
||||
// those pairs are contradictory and the unification is impossible.
|
||||
if(!undefinedPairs.isEmpty())
|
||||
return new HashSet<>();
|
||||
|
||||
/* Up to here, no cartesian products are calculated.
|
||||
* filters for pairs and sets can be applied here */
|
||||
|
||||
// Sub cartesian products of the second level (pattern matched) sets
|
||||
// "the big (x)"
|
||||
for(Set<Set<Set<UnifyPair>>> secondLevelSet : secondLevelSets) {
|
||||
List<Set<Set<UnifyPair>>> secondLevelSetList = new ArrayList<>(secondLevelSet);
|
||||
Set<List<Set<UnifyPair>>> cartResult = setOps.cartesianProduct(secondLevelSetList);
|
||||
|
||||
// Flatten and add to top level sets
|
||||
Set<Set<UnifyPair>> flat = new HashSet<>();
|
||||
for(List<Set<UnifyPair>> s : cartResult) {
|
||||
Set<UnifyPair> flat1 = new HashSet<>();
|
||||
for(Set<UnifyPair> s1 : s)
|
||||
flat1.addAll(s1);
|
||||
flat.add(flat1);
|
||||
}
|
||||
topLevelSets.add(flat);
|
||||
}
|
||||
|
||||
// Cartesian product over all (up to 10) top level sets
|
||||
Set<Set<Set<UnifyPair>>> eqPrimeSet = setOps.cartesianProduct(topLevelSets)
|
||||
.stream().map(x -> new HashSet<>(x))
|
||||
.collect(Collectors.toCollection(HashSet::new));
|
||||
//System.out.println(result);
|
||||
|
||||
Set<Set<UnifyPair>> eqPrimePrimeSet = new HashSet<>();
|
||||
|
||||
Set<TypeUnifyTask> forks = new HashSet<>();
|
||||
for(Set<Set<UnifyPair>> setToFlatten : eqPrimeSet) {
|
||||
// Flatten the cartesian product
|
||||
Set<UnifyPair> eqPrime = new HashSet<>();
|
||||
setToFlatten.stream().forEach(x -> eqPrime.addAll(x));
|
||||
|
||||
/*
|
||||
* Step 5: Substitution
|
||||
*/
|
||||
Optional<Set<UnifyPair>> eqPrimePrime = rules.subst(eqPrime);
|
||||
|
||||
|
||||
/*
|
||||
* Step 6 a) Restart (fork) for pairs where subst was applied
|
||||
*/
|
||||
Set<TypeUnifyTask> restart = new HashSet<>();
|
||||
|
||||
if (eqPrime.equals(eq))
|
||||
eqPrimePrimeSet.add(eqPrime);
|
||||
else if(eqPrimePrime.isPresent()) {
|
||||
TypeUnifyTask fork = new TypeUnifyTask(eqPrimePrime.get(), fc);
|
||||
forks.add(fork);
|
||||
fork.fork();
|
||||
}
|
||||
//eqPrimePrimeSet.addAll(this.unify(eqPrimePrime.get(), fc));
|
||||
else {
|
||||
TypeUnifyTask fork = new TypeUnifyTask(eqPrime, fc);
|
||||
forks.add(fork);
|
||||
fork.fork();
|
||||
// eqPrimePrimeSet.addAll(this.unify(eqPrime, fc));
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Step 6 b) Build the union over everything.
|
||||
*/
|
||||
|
||||
// TODO Parallel stream und synced set?
|
||||
for(TypeUnifyTask fork : forks)
|
||||
eqPrimePrimeSet.addAll(fork.join());
|
||||
|
||||
/*
|
||||
* Step 7: Filter empty sets;
|
||||
*/
|
||||
return eqPrimePrimeSet.stream().filter(x -> isSolvedForm(x)).collect(Collectors.toCollection(HashSet::new));
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* Checks whether a set of pairs is in solved form.
|
||||
* @param eqPrimePrime The set of pair
|
||||
* @return True if in solved form, false otherwise.
|
||||
*/
|
||||
protected boolean isSolvedForm(Set<UnifyPair> eqPrimePrime) {
|
||||
for(UnifyPair pair : eqPrimePrime) {
|
||||
UnifyType lhsType = pair.getLhsType();
|
||||
UnifyType rhsType = pair.getRhsType();
|
||||
|
||||
if(!(lhsType instanceof PlaceholderType))
|
||||
return false;
|
||||
|
||||
// If operator is not equals, both sides must be placeholders
|
||||
if(pair.getPairOp() != PairOperator.EQUALSDOT && !(rhsType instanceof PlaceholderType))
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
/**
|
||||
* Repeatedly applies type unification rules to a set of equations.
|
||||
* This is step one of the unification algorithm.
|
||||
* @return The set of pairs that results from repeated application of the inference rules.
|
||||
*/
|
||||
protected Set<UnifyPair> applyTypeUnificationRules(Set<UnifyPair> eq, IFiniteClosure fc) {
|
||||
|
||||
/*
|
||||
* Rule Application Strategy:
|
||||
*
|
||||
* 1. Swap all pairs and erase all erasable pairs
|
||||
* 2. Apply all possible rules to a single pair, then move it to the result set.
|
||||
* Iterating over pairs first, then iterating over rules prevents the application
|
||||
* of rules to a "finished" pair over and over.
|
||||
* 2.1 Apply all rules repeatedly except for erase rules. If
|
||||
* the application of a rule creates new pairs, check immediately
|
||||
* against the erase rules.
|
||||
*/
|
||||
|
||||
|
||||
LinkedHashSet<UnifyPair> targetSet = new LinkedHashSet<UnifyPair>();
|
||||
LinkedList<UnifyPair> eqQueue = new LinkedList<>();
|
||||
|
||||
/*
|
||||
* Swap all pairs and erase all erasable pairs
|
||||
*/
|
||||
eq.forEach(x -> swapAddOrErase(x, fc, eqQueue));
|
||||
|
||||
/*
|
||||
* Apply rules until the queue is empty
|
||||
*/
|
||||
while(!eqQueue.isEmpty()) {
|
||||
UnifyPair pair = eqQueue.pollFirst();
|
||||
|
||||
// ReduceUp, ReduceLow, ReduceUpLow
|
||||
Optional<UnifyPair> opt = rules.reduceUpLow(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceLow(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceUp(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceWildcardLow(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceWildcardLowRight(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceWildcardUp(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceWildcardUpRight(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceWildcardLowUp(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceWildcardUpLow(pair);
|
||||
opt = opt.isPresent() ? opt : rules.reduceWildcardLeft(pair);
|
||||
|
||||
// Reduce TPH
|
||||
opt = opt.isPresent() ? opt : rules.reduceTph(pair);
|
||||
|
||||
// One of the rules has been applied
|
||||
if(opt.isPresent()) {
|
||||
swapAddOrErase(opt.get(), fc, eqQueue);
|
||||
continue;
|
||||
}
|
||||
|
||||
// Reduce1, Reduce2, ReduceExt, ReduceSup, ReduceEq
|
||||
Optional<Set<UnifyPair>> optSet = rules.reduce1(pair, fc);
|
||||
optSet = optSet.isPresent() ? optSet : rules.reduce2(pair);
|
||||
optSet = optSet.isPresent() ? optSet : rules.reduceExt(pair, fc);
|
||||
optSet = optSet.isPresent() ? optSet : rules.reduceSup(pair, fc);
|
||||
optSet = optSet.isPresent() ? optSet : rules.reduceEq(pair);
|
||||
|
||||
// ReduceTphExt, ReduceTphSup
|
||||
optSet = optSet.isPresent() ? optSet : rules.reduceTphExt(pair);
|
||||
optSet = optSet.isPresent() ? optSet : rules.reduceTphSup(pair);
|
||||
|
||||
// One of the rules has been applied
|
||||
if(optSet.isPresent()) {
|
||||
optSet.get().forEach(x -> swapAddOrErase(x, fc, eqQueue));
|
||||
continue;
|
||||
}
|
||||
|
||||
// Adapt, AdaptExt, AdaptSup
|
||||
opt = rules.adapt(pair, fc);
|
||||
opt = opt.isPresent() ? opt : rules.adaptExt(pair, fc);
|
||||
opt = opt.isPresent() ? opt : rules.adaptSup(pair, fc);
|
||||
|
||||
// One of the rules has been applied
|
||||
if(opt.isPresent()) {
|
||||
swapAddOrErase(opt.get(), fc, eqQueue);
|
||||
continue;
|
||||
}
|
||||
|
||||
// None of the rules has been applied
|
||||
targetSet.add(pair);
|
||||
}
|
||||
|
||||
return targetSet;
|
||||
}
|
||||
|
||||
/**
|
||||
* Applies the rule swap to a pair if possible. Then adds the pair to the set if no erase rule applies.
|
||||
* If an erase rule applies, the pair is not added (erased).
|
||||
* @param pair The pair to swap and add or erase.
|
||||
* @param collection The collection to which the pairs are added.
|
||||
*/
|
||||
protected void swapAddOrErase(UnifyPair pair, IFiniteClosure fc, Collection<UnifyPair> collection) {
|
||||
Optional<UnifyPair> opt = rules.swap(pair);
|
||||
UnifyPair pair2 = opt.isPresent() ? opt.get() : pair;
|
||||
|
||||
if(rules.erase1(pair2, fc) || rules.erase3(pair2) || rules.erase2(pair2, fc))
|
||||
return;
|
||||
|
||||
collection.add(pair2);
|
||||
}
|
||||
|
||||
/**
|
||||
* Splits the equation eq into a set eq1s where both terms are type variables,
|
||||
* and a set eq2s where one of both terms is not a type variable.
|
||||
* @param eq Set of pairs to be splitted.
|
||||
* @param eq1s Subset of eq where both terms are type variables.
|
||||
* @param eq2s eq/eq1s.
|
||||
*/
|
||||
protected void splitEq(Set<UnifyPair> eq, Set<UnifyPair> eq1s, Set<UnifyPair> eq2s) {
|
||||
for(UnifyPair pair : eq)
|
||||
if(pair.getLhsType() instanceof PlaceholderType && pair.getRhsType() instanceof PlaceholderType)
|
||||
eq1s.add(pair);
|
||||
else
|
||||
eq2s.add(pair);
|
||||
}
|
||||
|
||||
/**
|
||||
* Creates sets of pairs specified in the fourth step. Does not calculate cartesian products.
|
||||
* @param undefined All pairs that did not match one of the 8 cases are added to this set.
|
||||
* @return The set of the eight cases (without empty sets). Each case is a set, containing sets generated
|
||||
* from the pairs that matched the case. Each generated set contains singleton sets or sets with few elements
|
||||
* (as in case 1 where sigma is added to the innermost set).
|
||||
*/
|
||||
protected Set<Set<Set<Set<UnifyPair>>>> calculatePairSets(Set<UnifyPair> eq2s, IFiniteClosure fc, Set<UnifyPair> undefined) {
|
||||
List<Set<Set<Set<UnifyPair>>>> result = new ArrayList<>(8);
|
||||
|
||||
// Init all 8 cases
|
||||
for(int i = 0; i < 8; i++)
|
||||
result.add(new HashSet<>());
|
||||
|
||||
for(UnifyPair pair : eq2s) {
|
||||
PairOperator pairOp = pair.getPairOp();
|
||||
UnifyType lhsType = pair.getLhsType();
|
||||
UnifyType rhsType = pair.getRhsType();
|
||||
|
||||
// Case 1: (a <. Theta')
|
||||
if(pairOp == PairOperator.SMALLERDOT && lhsType instanceof PlaceholderType)
|
||||
result.get(0).add(unifyCase1((PlaceholderType) pair.getLhsType(), pair.getRhsType(), fc));
|
||||
|
||||
// Case 2: (a <.? ? ext Theta')
|
||||
else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof PlaceholderType && rhsType instanceof ExtendsType)
|
||||
result.get(1).add(unifyCase2((PlaceholderType) pair.getLhsType(), (ExtendsType) pair.getRhsType(), fc));
|
||||
|
||||
// Case 3: (a <.? ? sup Theta')
|
||||
else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof PlaceholderType && rhsType instanceof SuperType)
|
||||
result.get(2).add(unifyCase3((PlaceholderType) lhsType, (SuperType) rhsType, fc));
|
||||
|
||||
// Case 4 was replaced by an inference rule
|
||||
// Case 4: (a <.? Theta')
|
||||
//else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof PlaceholderType)
|
||||
// result.get(3).add(unifyCase4((PlaceholderType) lhsType, rhsType, fc));
|
||||
|
||||
// Case 5: (Theta <. a)
|
||||
else if(pairOp == PairOperator.SMALLERDOT && rhsType instanceof PlaceholderType)
|
||||
result.get(4).add(unifyCase5(lhsType, (PlaceholderType) rhsType, fc));
|
||||
|
||||
// Case 6 was replaced by an inference rule.
|
||||
// Case 6: (? ext Theta <.? a)
|
||||
//else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof ExtendsType && rhsType instanceof PlaceholderType)
|
||||
// result.get(5).add(unifyCase6((ExtendsType) lhsType, (PlaceholderType) rhsType, fc));
|
||||
|
||||
// Case 7 was replaced by an inference rule
|
||||
// Case 7: (? sup Theta <.? a)
|
||||
//else if(pairOp == PairOperator.SMALLERDOTWC && lhsType instanceof SuperType && rhsType instanceof PlaceholderType)
|
||||
// result.get(6).add(unifyCase7((SuperType) lhsType, (PlaceholderType) rhsType, fc));
|
||||
|
||||
// Case 8: (Theta <.? a)
|
||||
else if(pairOp == PairOperator.SMALLERDOTWC && rhsType instanceof PlaceholderType)
|
||||
result.get(7).add(unifyCase8(lhsType, (PlaceholderType) rhsType, fc));
|
||||
// Case unknown: If a pair fits no other case, then the type unification has failed.
|
||||
// Through application of the rules, every pair should have one of the above forms.
|
||||
// Pairs that do not have one of the aboves form are contradictory.
|
||||
else
|
||||
undefined.add(pair);
|
||||
}
|
||||
|
||||
// Filter empty sets or sets that only contain an empty set.
|
||||
return result.stream().map(x -> x.stream().filter(y -> y.size() > 0).collect(Collectors.toCollection(HashSet::new)))
|
||||
.filter(x -> x.size() > 0).collect(Collectors.toCollection(HashSet::new));
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian product Case 1: (a <. Theta')
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase1(PlaceholderType a, UnifyType thetaPrime, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
|
||||
Set<UnifyType> cs = fc.getAllTypesByName(thetaPrime.getName());
|
||||
cs.add(thetaPrime);
|
||||
|
||||
for(UnifyType c : cs) {
|
||||
Set<UnifyType> thetaQs = fc.getChildren(c).stream().collect(Collectors.toCollection(HashSet::new));
|
||||
thetaQs.add(thetaPrime);
|
||||
Set<UnifyType> thetaQPrimes = new HashSet<>();
|
||||
TypeParams cParams = c.getTypeParams();
|
||||
if(cParams.size() == 0)
|
||||
thetaQPrimes.add(c);
|
||||
else {
|
||||
ArrayList<Set<UnifyType>> candidateParams = new ArrayList<>();
|
||||
|
||||
for(UnifyType param : cParams)
|
||||
candidateParams.add(fc.grArg(param));
|
||||
|
||||
for(TypeParams tp : permuteParams(candidateParams))
|
||||
thetaQPrimes.add(c.setTypeParams(tp));
|
||||
}
|
||||
|
||||
for(UnifyType tqp : thetaQPrimes) {
|
||||
Optional<Unifier> opt = stdUnify.unify(tqp, thetaPrime);
|
||||
if (!opt.isPresent())
|
||||
continue;
|
||||
|
||||
Unifier unifier = opt.get();
|
||||
unifier.swapPlaceholderSubstitutions(thetaPrime.getTypeParams());
|
||||
Set<UnifyPair> substitutionSet = new HashSet<>();
|
||||
for (Entry<PlaceholderType, UnifyType> sigma : unifier)
|
||||
substitutionSet.add(new UnifyPair(sigma.getKey(), sigma.getValue(), PairOperator.EQUALSDOT));
|
||||
|
||||
List<UnifyType> freshTphs = new ArrayList<>();
|
||||
for (UnifyType tq : thetaQs) {
|
||||
Set<UnifyType> smaller = fc.smaller(unifier.apply(tq));
|
||||
for(UnifyType theta : smaller) {
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
|
||||
for(int i = 0; i < theta.getTypeParams().size(); i++) {
|
||||
if(freshTphs.size()-1 < i)
|
||||
freshTphs.add(PlaceholderType.freshPlaceholder());
|
||||
resultPrime.add(new UnifyPair(freshTphs.get(i), theta.getTypeParams().get(i), PairOperator.SMALLERDOTWC));
|
||||
}
|
||||
|
||||
UnifyType freshTheta = theta.setTypeParams(new TypeParams(freshTphs.toArray(new UnifyType[0])));
|
||||
resultPrime.add(new UnifyPair(a, freshTheta, PairOperator.EQUALSDOT));
|
||||
resultPrime.addAll(substitutionSet);
|
||||
result.add(resultPrime);
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 2: (a <.? ? ext Theta')
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase2(PlaceholderType a, ExtendsType extThetaPrime, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
|
||||
UnifyType aPrime = PlaceholderType.freshPlaceholder();
|
||||
UnifyType extAPrime = new ExtendsType(aPrime);
|
||||
UnifyType thetaPrime = extThetaPrime.getExtendedType();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, thetaPrime, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, extAPrime, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(aPrime, thetaPrime, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 3: (a <.? ? sup Theta')
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase3(PlaceholderType a, SuperType subThetaPrime, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
|
||||
UnifyType aPrime = PlaceholderType.freshPlaceholder();
|
||||
UnifyType supAPrime = new SuperType(aPrime);
|
||||
UnifyType thetaPrime = subThetaPrime.getSuperedType();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(thetaPrime, a, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, supAPrime, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(thetaPrime, aPrime, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 4: (a <.? Theta')
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase4(PlaceholderType a, UnifyType thetaPrime, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, thetaPrime, PairOperator.EQUALSDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 5: (Theta <. a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase5(UnifyType theta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
for(UnifyType thetaS : fc.greater(theta)) {
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
|
||||
UnifyType[] freshTphs = new UnifyType[thetaS.getTypeParams().size()];
|
||||
for(int i = 0; i < freshTphs.length; i++) {
|
||||
freshTphs[i] = PlaceholderType.freshPlaceholder();
|
||||
resultPrime.add(new UnifyPair(thetaS.getTypeParams().get(i), freshTphs[i], PairOperator.SMALLERDOTWC));
|
||||
}
|
||||
|
||||
resultPrime.add(new UnifyPair(a, thetaS.setTypeParams(new TypeParams(freshTphs)), PairOperator.EQUALSDOT));
|
||||
result.add(resultPrime);
|
||||
}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 6: (? ext Theta <.? a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase6(ExtendsType extTheta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
UnifyType freshTph = PlaceholderType.freshPlaceholder();
|
||||
UnifyType extFreshTph = new ExtendsType(freshTph);
|
||||
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, extFreshTph, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(extTheta.getExtendedType(), freshTph, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 7: (? sup Theta <.? a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase7(SuperType supTheta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
|
||||
UnifyType aPrime = PlaceholderType.freshPlaceholder();
|
||||
UnifyType supAPrime = new SuperType(aPrime);
|
||||
UnifyType theta = supTheta.getSuperedType();
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, supAPrime, PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(aPrime, theta, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Cartesian Product Case 8: (Theta <.? a)
|
||||
*/
|
||||
protected Set<Set<UnifyPair>> unifyCase8(UnifyType theta, PlaceholderType a, IFiniteClosure fc) {
|
||||
Set<Set<UnifyPair>> result = new HashSet<>();
|
||||
//for(UnifyType thetaS : fc.grArg(theta)) {
|
||||
Set<UnifyPair> resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, theta, PairOperator.EQUALSDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
UnifyType freshTph = PlaceholderType.freshPlaceholder();
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, new ExtendsType(freshTph), PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(theta, freshTph, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
|
||||
resultPrime = new HashSet<>();
|
||||
resultPrime.add(new UnifyPair(a, new SuperType(freshTph), PairOperator.EQUALSDOT));
|
||||
resultPrime.add(new UnifyPair(freshTph, theta, PairOperator.SMALLERDOT));
|
||||
result.add(resultPrime);
|
||||
//}
|
||||
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Takes a set of candidates for each position and computes all possible permutations.
|
||||
* @param candidates The length of the list determines the number of type params. Each set
|
||||
* contains the candidates for the corresponding position.
|
||||
*/
|
||||
protected Set<TypeParams> permuteParams(ArrayList<Set<UnifyType>> candidates) {
|
||||
Set<TypeParams> result = new HashSet<>();
|
||||
permuteParams(candidates, 0, result, new UnifyType[candidates.size()]);
|
||||
return result;
|
||||
}
|
||||
|
||||
/**
|
||||
* Takes a set of candidates for each position and computes all possible permutations.
|
||||
* @param candidates The length of the list determines the number of type params. Each set
|
||||
* contains the candidates for the corresponding position.
|
||||
* @param idx Idx for the current permutatiton.
|
||||
* @param result Set of all permutations found so far
|
||||
* @param current The permutation of type params that is currently explored
|
||||
*/
|
||||
private void permuteParams(ArrayList<Set<UnifyType>> candidates, int idx, Set<TypeParams> result, UnifyType[] current) {
|
||||
if(candidates.size() == idx) {
|
||||
result.add(new TypeParams(Arrays.copyOf(current, current.length)));
|
||||
return;
|
||||
}
|
||||
|
||||
Set<UnifyType> localCandidates = candidates.get(idx);
|
||||
|
||||
for(UnifyType t : localCandidates) {
|
||||
current[idx] = t;
|
||||
permuteParams(candidates, idx+1, result, current);
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -792,52 +792,52 @@ public class UnifyTest extends TypeUnify {
|
||||
|
||||
}
|
||||
|
||||
@Test
|
||||
public void permuteParamsTest() {
|
||||
TypeFactory tf = new TypeFactory();
|
||||
ArrayList<Set<UnifyType>> candidates = new ArrayList<>();
|
||||
|
||||
UnifyType p11 = tf.getPlaceholderType("p11");
|
||||
UnifyType p12 = tf.getExtendsType(tf.getSimpleType("p12"));
|
||||
UnifyType p13 = tf.getSimpleType("p13");
|
||||
UnifyType p21 = tf.getPlaceholderType("p21");
|
||||
UnifyType p22 = tf.getPlaceholderType("p22");
|
||||
UnifyType p31 = tf.getSimpleType("p31", "T");
|
||||
|
||||
Set<UnifyType> p1 = new HashSet<>();
|
||||
p1.add(p11);
|
||||
p1.add(p12);
|
||||
p1.add(p13);
|
||||
|
||||
Set<UnifyType> p2 = new HashSet<>();
|
||||
p2.add(p21);
|
||||
p2.add(p22);
|
||||
|
||||
Set<UnifyType> p3 = new HashSet<>();
|
||||
p3.add(p31);
|
||||
|
||||
candidates.add(p1);
|
||||
candidates.add(p2);
|
||||
candidates.add(p3);
|
||||
|
||||
|
||||
/*
|
||||
* Expected Result:
|
||||
* {<x, y, z> | x in { p11, p12, p13}, y in { p21, p22 }, z in { p31 }}
|
||||
*/
|
||||
Set<TypeParams> expected = Arrays.stream(new TypeParams[] {
|
||||
new TypeParams(p11, p21, p31),
|
||||
new TypeParams(p11, p22, p31),
|
||||
new TypeParams(p12, p21, p31),
|
||||
new TypeParams(p12, p22, p31),
|
||||
new TypeParams(p13, p21, p31),
|
||||
new TypeParams(p13, p22, p31)
|
||||
}).collect(Collectors.toSet());
|
||||
|
||||
Set<TypeParams> actual = permuteParams(candidates);
|
||||
|
||||
Assert.assertEquals(expected, actual);
|
||||
}
|
||||
// @Test
|
||||
// public void permuteParamsTest() {
|
||||
// TypeFactory tf = new TypeFactory();
|
||||
// ArrayList<Set<UnifyType>> candidates = new ArrayList<>();
|
||||
//
|
||||
// UnifyType p11 = tf.getPlaceholderType("p11");
|
||||
// UnifyType p12 = tf.getExtendsType(tf.getSimpleType("p12"));
|
||||
// UnifyType p13 = tf.getSimpleType("p13");
|
||||
// UnifyType p21 = tf.getPlaceholderType("p21");
|
||||
// UnifyType p22 = tf.getPlaceholderType("p22");
|
||||
// UnifyType p31 = tf.getSimpleType("p31", "T");
|
||||
//
|
||||
// Set<UnifyType> p1 = new HashSet<>();
|
||||
// p1.add(p11);
|
||||
// p1.add(p12);
|
||||
// p1.add(p13);
|
||||
//
|
||||
// Set<UnifyType> p2 = new HashSet<>();
|
||||
// p2.add(p21);
|
||||
// p2.add(p22);
|
||||
//
|
||||
// Set<UnifyType> p3 = new HashSet<>();
|
||||
// p3.add(p31);
|
||||
//
|
||||
// candidates.add(p1);
|
||||
// candidates.add(p2);
|
||||
// candidates.add(p3);
|
||||
//
|
||||
//
|
||||
// /*
|
||||
// * Expected Result:
|
||||
// * {<x, y, z> | x in { p11, p12, p13}, y in { p21, p22 }, z in { p31 }}
|
||||
// */
|
||||
// Set<TypeParams> expected = Arrays.stream(new TypeParams[] {
|
||||
// new TypeParams(p11, p21, p31),
|
||||
// new TypeParams(p11, p22, p31),
|
||||
// new TypeParams(p12, p21, p31),
|
||||
// new TypeParams(p12, p22, p31),
|
||||
// new TypeParams(p13, p21, p31),
|
||||
// new TypeParams(p13, p22, p31)
|
||||
// }).collect(Collectors.toSet());
|
||||
//
|
||||
// Set<TypeParams> actual = permuteParams(candidates);
|
||||
//
|
||||
// Assert.assertEquals(expected, actual);
|
||||
// }
|
||||
|
||||
private Set<Set<UnifyPair>> filterGeneratedTPHsMultiple(Set<Set<UnifyPair>> set) {
|
||||
return set.stream().map(x -> filterGeneratedTPHs(x)).collect(Collectors.toSet());
|
||||
|
||||
Loading…
Reference in New Issue
Block a user