Add to ORKGDataflow languages provide natural support for specifying constraints between objects in dynamic applications, where programs need to react efficiently to changes of their envi-ronment. Researchers have long investigated how to take ad-vantage of dataflow constraints by embedding them into pro-cedural languages. Previous mixed imperative/dataflow sys-tems, however, require syntactic extensions or libraries of ad hoc data types for binding the imperative program to the dataflow solver. In this paper we propose a novel approach that smoothly combines the two paradigms without placing undue burden on the programmer. In our framework, programmers can define ordinary statements of the imperative host language that enforce constraints between obj...