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ASF GitHub Bot commented on FLINK-7147: --------------------------------------- Github user tedyu commented on a diff in the pull request: https://github.com/apache/flink/pull/4296#discussion_r135366609 --- Diff: flink-libraries/flink-cep/src/main/java/org/apache/flink/cep/nfa/compiler/NFACompiler.java --- @@ -526,18 +551,32 @@ private boolean isPatternOptional(Pattern<T, ?> pattern) { return createGroupPatternState((GroupPattern) currentPattern, sinkState, proceedState, isOptional); } - final IterativeCondition<T> trueFunction = getTrueFunction(); - final State<T> singletonState = createState(currentPattern.getName(), State.StateType.Normal); // if event is accepted then all notPatterns previous to the optional states are no longer valid final State<T> sink = copyWithoutTransitiveNots(sinkState); singletonState.addTake(sink, takeCondition); + // if no element accepted the previous nots are still valid. + final IterativeCondition<T> proceedCondition = getTrueFunction(); + // for the first state of a group pattern, its PROCEED edge should point to the following state of // that group pattern and the edge will be added at the end of creating the NFA for that group pattern if (isOptional && !headOfGroup(currentPattern)) { - // if no element accepted the previous nots are still valid. - singletonState.addProceed(proceedState, trueFunction); + if (currentPattern.getQuantifier().hasProperty(Quantifier.QuantifierProperty.GREEDY)) { + final IterativeCondition<T> untilCondition = + (IterativeCondition<T>) currentPattern.getUntilCondition(); + if (untilCondition != null) { + singletonState.addProceed( + originalStateMap.get(proceedState.getName()), + new AndCondition<>(proceedCondition, untilCondition)); + } + singletonState.addProceed(proceedState, + untilCondition != null --- End diff -- Redundant check - see line 568 > Support greedy quantifier in CEP > -------------------------------- > > Key: FLINK-7147 > URL: https://issues.apache.org/jira/browse/FLINK-7147 > Project: Flink > Issue Type: Sub-task > Components: CEP, Table API & SQL > Reporter: Dian Fu > Assignee: Dian Fu > > Greedy quantifier will try to match the token as many times as possible. For > example, for pattern {{a b* c}} (skip till next is used) and inputs {{a b1 b2 > c}}, if the quantifier for {{b}} is greedy, it will only output {{a b1 b2 c}}. -- This message was sent by Atlassian JIRA (v6.4.14#64029)