Identifying Sub-sequences in Input Sequences

Purpose¶

This function attempts to find the next sub-sequence of the inputSequence that matches the regex pattern. It returns true if such a sub sequence exists, or returns false otherwise

Prerequisites¶

Save this sample. If there is no syntax error, the following messages would be shown on the console.

* Siddhi App RegexExecutionSample successfully deployed.

Executing the Sample¶

Start the Siddhi application by clicking on 'Run'.
If the Siddhi application starts successfully, the following messages would be shown on the console.
```
* RegexExecutionSample.siddhi - Started Successfully!
```

Testing the Sample¶

You can publish data event to the file, through event simulator.

Open event simulator by clicking on the second icon or press Ctrl+Shift+I.
In the Single Simulation tab of the panel, select values as follows:
- Siddhi App Name : RegexExecutionSample
- Stream Name : SweetProductionStream
Enter following values in the fields and send,
```
name: chocolate cake
startingIndex: 0
```
Enter following values in the fields and send
```
name: coffee cake
startingIndex: 0
```

Viewing the Results¶

Messages similar to the following would be shown on the console.

INFO {io.siddhi.core.stream.output.sink.LogSink} - RegexExecutionSample : ChocolateProductStream : Event{timestamp=1513759840093, data=[chocolate cake, true], isExpired=false}
INFO {io.siddhi.core.stream.output.sink.LogSink} - RegexExecutionSample : ChocolateProductStream : Event{timestamp=1513759907324, data=[coffee cake, false], isExpired=false}

@App:name("RegexExecutionSample")
@App:description('Finds if a sweet is a chocolate product.')

define stream SweetProductionStream (name string, startingIndex int);

@sink(type='log')
define stream ChocolateProductStream(name string, isAChocolateProduct bool);

from SweetProductionStream
select name, regex:find("^chocolate(\s*[a-zA-Z]+)", str:lower(name), startingIndex) as isAChocolateProduct
insert into ChocolateProductStream;