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 for an answer stream providing higher level filtering facilities as well as unification and join operations.

Author:

Kasper Piskorski

Field Summary

Fields

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

Constructor Summary

Constructors

Constructor and Description
QueryAnswerStream()

Method Summary

Modifier and Type	Method and Description
static boolean	entityTypeFilter(Map<VarName,Concept> answer, Set<TypeAtom> types)
static <T> java.util.stream.Stream<T>	join(java.util.function.BiFunction<T,T,java.util.stream.Stream<T>> function, java.util.stream.Stream<T> s1, java.util.stream.Stream<T> s2) perform a lazy join operation on two streams (stream and stream2)
static java.util.stream.Stream<Map<VarName,Concept>>	join(java.util.stream.Stream<Map<VarName,Concept>> stream, java.util.stream.Stream<Map<VarName,Concept>> stream2) lazy stream join
static Map<VarName,Concept>	joinOperator(Map<VarName,Concept> m1, Map<VarName,Concept> m2)
static boolean	knownFilter(Map<VarName,Concept> answer, java.util.stream.Stream<Map<VarName,Concept>> known)
static boolean	nonEqualsFilter(Map<VarName,Concept> answer, Set<NotEquals> atoms)
static java.util.stream.Stream<Map<VarName,Concept>>	permuteOperator(Map<VarName,Concept> answer, Set<Map<VarName,VarName>> unifierSet)
static boolean	subFilter(Map<VarName,Concept> answer, Set<IdPredicate> subs)
static java.util.stream.Stream<Map<VarName,Concept>>	unify(java.util.stream.Stream<Map<VarName,Concept>> answers, Map<VarName,VarName> unifiers) unify answer stream by applying unifiers
static Map<VarName,Concept>	varFilterOperator(Map<VarName,Concept> answer, Set<VarName> vars)

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<Map<VarName,Concept>,Set<VarName>,java.util.stream.Stream<Map<VarName,Concept>>> varFilterFunction

permuteFunction

public static final java.util.function.BiFunction<Map<VarName,Concept>,Set<Map<VarName,VarName>>,java.util.stream.Stream<Map<VarName,Concept>>> permuteFunction

joinFunction

public static final java.util.function.BiFunction<Map<VarName,Concept>,Map<VarName,Concept>,java.util.stream.Stream<Map<VarName,Concept>>> joinFunction

Constructor Detail

QueryAnswerStream

public QueryAnswerStream()

Method Detail

varFilterOperator

public static Map<VarName,Concept> varFilterOperator(Map<VarName,Concept> answer,
                                                     Set<VarName> vars)

knownFilter

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

nonEqualsFilter

public static boolean nonEqualsFilter(Map<VarName,Concept> answer,
                                      Set<NotEquals> atoms)

subFilter

public static boolean subFilter(Map<VarName,Concept> answer,
                                Set<IdPredicate> subs)

entityTypeFilter

public static boolean entityTypeFilter(Map<VarName,Concept> answer,
                                       Set<TypeAtom> types)

permuteOperator

public static java.util.stream.Stream<Map<VarName,Concept>> permuteOperator(Map<VarName,Concept> answer,
                                                                            Set<Map<VarName,VarName>> unifierSet)

joinOperator

public static Map<VarName,Concept> joinOperator(Map<VarName,Concept> m1,
                                                Map<VarName,Concept> m2)

unify

public static java.util.stream.Stream<Map<VarName,Concept>> unify(java.util.stream.Stream<Map<VarName,Concept>> answers,
                                                                  Map<VarName,VarName> unifiers)

unify answer stream by applying unifiers

Parameters:

answers - stream of answers to be unified

unifiers - to apply on stream elements

Returns:

unified answer stream

join

public static java.util.stream.Stream<Map<VarName,Concept>> join(java.util.stream.Stream<Map<VarName,Concept>> stream,
                                                                 java.util.stream.Stream<Map<VarName,Concept>> stream2)

lazy stream join

Parameters:

stream - left stream operand

stream2 - right stream operand

Returns:

joined stream

join

public static <T> java.util.stream.Stream<T> join(java.util.function.BiFunction<T,T,java.util.stream.Stream<T>> function,
                                                  java.util.stream.Stream<T> s1,
                                                  java.util.stream.Stream<T> s2)

perform a lazy join operation on two streams (stream and stream2)

Parameters:

function - joining function

s1 - left operand of join operation

s2 - right operand of join operation

Returns:

joined stream