Structured synchronous reactive programming (SSRP) augments classical structured programming (SP) with continuous interaction with the environment.
We advocate SSRP as viable in multiple domains of reactive applications and propose a new abstraction mechanism for the synchronous language Céu:
"Organisms" extend objects with an execution body that composes multiple lines of execution to react to the environment independently.
Compositions bring structured reasoning to concurrency and can better describe state machines typical of reactive applications.
Organisms are subject to lexical scope and automatic memory management similar to stack-based allocation for local variables in SP.
We show that this model does not require garbage collection or a "free" primitive in the language, eliminating memory leaks by design.