Cartesian product as Stream

This commit is contained in:
JanUlrich 2021-01-07 20:47:10 +01:00
parent 2f37bb7313
commit 0dc8a53fca
6 changed files with 229 additions and 1 deletions

10
pom.xml
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@ -118,7 +118,15 @@ http://maven.apache.org/maven-v4_0_0.xsd">
</descriptorRefs>
</configuration>
</plugin>
</plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>9</source>
<target>9</target>
</configuration>
</plugin>
</plugins>
</build>
<repositories>
<repository>

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@ -6,6 +6,7 @@ import java.util.Collection;
import java.util.HashSet;
import java.util.Set;
//TODO: Remove this class
public class Constraint<A> extends HashSet<A> {
private static final long serialVersionUID = 1L;
private Boolean isInherited = false;//wird nur für die Method-Constraints benoetigt

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@ -0,0 +1,107 @@
package de.dhbwstuttgart.typeinference.constraints;
import java.util.*;
import java.util.function.BinaryOperator;
import java.util.function.Consumer;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
public class ConstraintSet2 {
Set<OderConstraint> oderConstraints = new HashSet<>();
public ConstraintSet2(Set<OderConstraint> constraints){
if(constraints.isEmpty())throw new RuntimeException("Empty constraint set");
this.oderConstraints = constraints;
}
@Override
public String toString(){
BinaryOperator<String> b = (x,y) -> x+y;
return "ODER:" + this.oderConstraints.stream().reduce("", (x,y) -> x.toString()+ "\n" +y, b);
}
private class ConstraintSpliterator implements Spliterator<Set<Pair>> {
private List<OderConstraint> constraints;
private long i = 0;
private long max = 0;
private List<Integer> sizes;
private List<Long> bases = new ArrayList<>();
ConstraintSpliterator(List<OderConstraint> constraints){
this.constraints = constraints;
sizes = constraints.stream().map(OderConstraint::getSize).collect(Collectors.toList());
long base = 1;
for(int size : sizes){
bases.add(base);
base *= size;
}
i = 0;
max = estimateSize() - 1;
}
ConstraintSpliterator(List<OderConstraint> constraints, long start, long end){
this(constraints);
i = start;
max = end;
}
@Override
public boolean tryAdvance(Consumer<? super Set<Pair>> consumer) {
if(i > max) return false;
consumer.accept(get(i));
i++;
return true;
}
private Set<Pair> get(long num){
Set<Pair> ret = new HashSet<>();
Iterator<Long> baseIt = bases.iterator();
for(OderConstraint constraint : constraints){
ret.addAll(constraint.get((int) ((num/baseIt.next())%constraint.getSize())));
}
return ret;
}
@Override
public Spliterator<Set<Pair>> trySplit() {
if(max - i < 2) return null;
long middle = i + ((max- i) / 2);
long maxOld = max;
max = middle - 1;
return new ConstraintSpliterator(constraints, middle, maxOld);
}
@Override
public long estimateSize() {
long ret = 1;
for (int size : sizes)ret*=size;
return ret;
}
@Override
public int characteristics() {
return ORDERED | SIZED | IMMUTABLE | NONNULL;
}
}
public Stream<Set<Pair>> cartesianProductParallel(){
return StreamSupport.stream(new ConstraintSpliterator(oderConstraints.stream().collect(Collectors.toList())), true);
}
/*
public Map<String, TypePlaceholder> generateTPHMap() {
HashMap<String, TypePlaceholder> ret = new HashMap<>();
constraints.map((Pair p) -> {
if (p.TA1 instanceof TypePlaceholder) {
ret.put(((TypePlaceholder) p.TA1).getName(), (TypePlaceholder) p.TA1);
}
if (p.TA2 instanceof TypePlaceholder) {
ret.put(((TypePlaceholder) p.TA2).getName(), (TypePlaceholder) p.TA2);
}
return null;
});
return ret;
}
*/
}

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@ -0,0 +1,26 @@
package de.dhbwstuttgart.typeinference.constraints;
import java.util.HashSet;
import java.util.Set;
public class ConstraintSetBuilder {
private Set<Pair> undConstraints = new HashSet<>();
private Set<OderConstraint> oderConstraints = new HashSet<>();
private boolean done = false;
public void addUndConstraint(Pair p){
undConstraints.add(p);
}
public void addOderConstraint(OderConstraint orConstraint) {
oderConstraints.add(orConstraint);
}
public ConstraintSet2 build(){
if(done)throw new RuntimeException("Trying to build cartesian product twice");
this.done = true;
if(!undConstraints.isEmpty())
oderConstraints.add(new OderConstraint(Set.of(undConstraints)));
return new ConstraintSet2(oderConstraints);
}
}

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@ -0,0 +1,24 @@
package de.dhbwstuttgart.typeinference.constraints;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
public class OderConstraint {
private final List<Set<Pair>> cons;
public OderConstraint(Set<Set<Pair>> orCons){
if(orCons.isEmpty())throw new RuntimeException("Empty constraint set");
for(Set<Pair> c : orCons){
if(c.isEmpty())throw new RuntimeException("Empty constraint set");
}
this.cons = orCons.stream().collect(Collectors.toList());
}
public int getSize(){
return cons.size();
}
public Set<Pair> get(int l) {
return cons.get(l);
}
}

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@ -0,0 +1,62 @@
package typeinference;
import de.dhbwstuttgart.parser.NullToken;
import de.dhbwstuttgart.syntaxtree.type.TypePlaceholder;
import de.dhbwstuttgart.typeinference.constraints.ConstraintSetBuilder;
import de.dhbwstuttgart.typeinference.constraints.OderConstraint;
import de.dhbwstuttgart.typeinference.constraints.Pair;
import org.junit.Test;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
public class ConstraintSetTests {
@Test
public void cartesianProductTestSingleConstraint(){
ConstraintSetBuilder builder = new ConstraintSetBuilder();
builder.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()))));
List<Set<Pair>> result = builder.build().cartesianProductParallel().collect(Collectors.toList());
assert result.size() == 1;
}
@Test
public void cartesianProductTestSingleOderConstraint(){
ConstraintSetBuilder builder = new ConstraintSetBuilder();
builder.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
List<Set<Pair>> result = builder.build().cartesianProductParallel().collect(Collectors.toList());
assert result.size() == 2;
}
@Test
public void cartesianProductTestTwoOderConstraint(){
ConstraintSetBuilder builder = new ConstraintSetBuilder();
builder.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
builder.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
List<Set<Pair>> result = builder.build().cartesianProductParallel().collect(Collectors.toList());
assert result.size() == 4;
}
@Test
public void cartesianProductTestThreeOderConstraint(){
ConstraintSetBuilder builder = new ConstraintSetBuilder();
builder.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
builder.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
builder.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()))));
List<Set<Pair>> result = builder.build().cartesianProductParallel().collect(Collectors.toList());
assert result.size() == 4;
ConstraintSetBuilder builder2 = new ConstraintSetBuilder();
builder2.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
builder2.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
builder2.addOderConstraint(new OderConstraint(Set.of(Set.of(generatePair()), Set.of(generatePair()))));
List<Set<Pair>> result2 = builder2.build().cartesianProductParallel().collect(Collectors.toList());
assert result2.stream().map( a -> a.stream().map(p -> p.TA1.toString()).reduce("", (x, y)-> x+" "+y)).collect(Collectors.toSet()).size() == 8;
assert result2.size() == 8;
}
public Pair generatePair(){
return new Pair(TypePlaceholder.fresh(new NullToken()), TypePlaceholder.fresh(new NullToken()));
}
}