EventScript: An event-processing language based on regular expressions with actions

EventScript is a simple but powerful language for programming reactive processes. A stream of incoming events is matched against a regular expression. Actions embedded within the regular expression are executed in response to the matching of patterns of events. These actions include assigning computed values to vari-ables and emitting output events. The definition of EventScript presented a number of novel and interesting language-design choices. EventScript has an efficient implementation, and has been used in a development environment for complex event-based applications. We have used EventScript to program both small examples and large industrial applications. Readers of EventScript programs find them easy to understand, and are com-fortable with the familiar model of matching regular expressions. Copyright © 2008 ACM.