If only one operand expression is of type string, then string conversion is now performed on the other operand to produce a string at runtime. For more details, see Additive operators.

The EPL language has been enhanced with some convenience methods for common operations such as checking if a string or sequence contains a specified substring or item, and determining if a string, sequence or dictionary is empty.

There is a method to get a sequence value with a fallback default if there is no value at the specified index:

There is also a powerful regular expression group search for strings that finds the first match and returns the text captured by each (...) group of the regular expression:

The following table lists all new methods:

For more information, see the API Reference for EPL (ApamaDoc) .

Instead of throwing an out of bounds exception, it is now possible to refer to items near the end of a sequence by specifying a negative index. For example, seq[-1] gives the last item in the sequence and seq[-2] gives the item before that. Negative sequence indexes can also be used in the sequence.remove() and sequence.insert() methods.

Note that negative values cannot be specified when accessing a sequence item using the any.getEntry() method.

It is no longer necessary to add an <any> cast around the first item in a sequence or dictionary literal that contains a mixture of different types. For example, the following sequence literal which produces a sequence<any>

can now be written more simply as

This simplifies the functional example given in EPL enhancements in 10.15.3: the <any> is no longer needed in the setFields call.

In EPL it is now possible to discard the return value of a function or expression and not assign it to a variable. This is useful if you only want the side effects of the function and do not need the return value. Be careful not to discard a return value that indicates important conditions that your program may need to use.

Previously, you had to write:

But now you can write:

See also Using an expression as a statement.

The com.apama.functional.Fn and com.apama.functional.Functional events now have a new method mapKeys which can return a dictionary container with modified keys. For more details, see Functional operators and the API Reference for EPL (ApamaDoc) .

The functional onTimeout action now returns the wait listener it creates so that it can be quit if needed. For more details, see Functional listeners.

EPL monitors are no longer terminated by default when an uncaught exception is thrown in some cases.

Programming errors and unexpected data in incoming events can cause an uncaught exception in EPL. This causes the monitor instance to be terminated, rendering the application unusable. To provide a better experience, exceptions thrown from listeners and stream listeners which are not caught no longer terminate the monitor instance. Instead, they just stop the handling of the current event.

Developers are still encouraged to correctly catch and handle the exceptions in their EPL. If an exception is thrown and not caught, it is still possible for the events to be lost and not correctly handled.

This is a change in behavior. Some users may be relying on this previous behavior, in combination with an ondie() action. EPL with an ondie() action retains the previous behavior of always terminating the monitor and calling ondie(). If you need to retain the previous behavior, you can add an empty ondie() action to your monitor.