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https://issues.apache.org/jira/browse/FLINK-3414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15402000#comment-15402000
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Till Rohrmann commented on FLINK-3414:
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Hi [~ivan.mushketyk], great to hear that you want to work on this issue.
The Scala support was partly added with FLINK-3708. However, we didn't add a
Scala DSL for the pattern definition yet. This means having a more succinct way
to specify in a more scalaesque way. The design for this language would be the
first step and should be discussed prior to starting the implementation.
The symbol "->" means "followedBy" and "||" is the or operator. The DSL example
does not have to represent the result of the design. It was intended to be an
inspiration how a future DSL could look like. So feel free to come up with your
own operator names to represent the different Pattern API concepts.
> Add Scala API for CEP's pattern definition
> ------------------------------------------
>
> Key: FLINK-3414
> URL: https://issues.apache.org/jira/browse/FLINK-3414
> Project: Flink
> Issue Type: Improvement
> Components: CEP
> Affects Versions: 1.0.0
> Reporter: Till Rohrmann
> Priority: Minor
>
> Currently, the CEP library only supports a Java API to specify complex event
> patterns. In order to make it a bit less verbose for Scala users, it would be
> nice to also add a Scala API for the CEP library.
> A Scala API would also allow to pass Scala's anonymous functions as filter
> conditions or as a select function, for example, or to use partial functions
> to distinguish between different events.
> Furthermore, the Scala API could be designed to feel a bit more like a DSL:
> {code}
> begin "start" where _.id >= 42 -> "middle_1" as classOf[Subclass] ||
> "middle_2" where _.name equals "foobar" -> "end" where x => x.id <= x.volume
> {code}
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