ai.grakn.graql.internal.reasoner.query

Class QueryAnswerStream

java.lang.Object

ai.grakn.graql.internal.reasoner.query.QueryAnswerStream

public class QueryAnswerStream
extends Object

Wrapper class providing higher level stream operations on answer streams

Author:

Kasper Piskorski

Field Summary

Fields

Modifier and Type	Field and Description
static java.util.function.BiFunction<Answer,Set<Unifier>,java.util.stream.Stream<Answer>>	permuteFunction
static java.util.function.BiFunction<Answer,Set<VarName>,java.util.stream.Stream<Answer>>	varFilterFunction

Constructor Summary

Constructors

Constructor and Description
QueryAnswerStream()

Method Summary

Modifier and Type	Method and Description
static boolean	entityTypeFilter(Answer answer, Set<TypeAtom> types)
static java.util.stream.Stream<Answer>	join(java.util.stream.Stream<Answer> stream, java.util.stream.Stream<Answer> stream2) lazy stream join
static java.util.stream.Stream<Answer>	join(java.util.stream.Stream<Answer> stream, java.util.stream.Stream<Answer> stream2, com.google.common.collect.ImmutableSet<VarName> joinVars, boolean explanation) lazy stream join with quasi- sideways information propagation
static java.util.stream.Stream<Answer>	joinWithInverse(java.util.stream.Stream<Answer> stream, java.util.stream.Stream<Answer> stream2, Map<javafx.util.Pair<VarName,Concept>,Set<Answer>> stream2InverseMap, com.google.common.collect.ImmutableSet<VarName> joinVars, boolean explanation) lazy stream join with fast lookup from inverse answer map
static boolean	knownFilter(Answer answer, java.util.stream.Stream<Answer> known)
static boolean	subFilter(Answer answer, Set<IdPredicate> subs)
static java.util.stream.Stream<Answer>	unify(java.util.stream.Stream<Answer> answers, Unifier unifier) unify answer stream by applying unifiers

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

varFilterFunction

public static final java.util.function.BiFunction<Answer,Set<VarName>,java.util.stream.Stream<Answer>> varFilterFunction

permuteFunction

public static final java.util.function.BiFunction<Answer,Set<Unifier>,java.util.stream.Stream<Answer>> permuteFunction

Constructor Detail

QueryAnswerStream

public QueryAnswerStream()

Method Detail

knownFilter

public static boolean knownFilter(Answer answer,
                                  java.util.stream.Stream<Answer> known)

subFilter

public static boolean subFilter(Answer answer,
                                Set<IdPredicate> subs)

entityTypeFilter

public static boolean entityTypeFilter(Answer answer,
                                       Set<TypeAtom> types)

unify

public static java.util.stream.Stream<Answer> unify(java.util.stream.Stream<Answer> answers,
                                                    Unifier unifier)

unify answer stream by applying unifiers

Parameters:

answers - stream of answers to be unified

unifier - to apply on stream elements

Returns:

unified answer stream

join

public static java.util.stream.Stream<Answer> join(java.util.stream.Stream<Answer> stream,
                                                   java.util.stream.Stream<Answer> stream2)

lazy stream join

Parameters:

stream - left stream operand

stream2 - right stream operand

Returns:

joined stream

join

public static java.util.stream.Stream<Answer> join(java.util.stream.Stream<Answer> stream,
                                                   java.util.stream.Stream<Answer> stream2,
                                                   com.google.common.collect.ImmutableSet<VarName> joinVars,
                                                   boolean explanation)

lazy stream join with quasi- sideways information propagation

Parameters:

stream - left stream operand

stream2 - right stream operand

joinVars - intersection on variables of two streams

Returns:

joined stream

joinWithInverse

public static java.util.stream.Stream<Answer> joinWithInverse(java.util.stream.Stream<Answer> stream,
                                                              java.util.stream.Stream<Answer> stream2,
                                                              Map<javafx.util.Pair<VarName,Concept>,Set<Answer>> stream2InverseMap,
                                                              com.google.common.collect.ImmutableSet<VarName> joinVars,
                                                              boolean explanation)

lazy stream join with fast lookup from inverse answer map

Parameters:

stream - left stream operand

stream2 - right stream operand

stream2InverseMap - inverse map of right operand from cache

joinVars - intersection on variables of two streams

Returns:

joined stream