Abstract. We present a lightweight type-and-effect system for Java programs that features two major innovations over extant object-oriented effects systems: initialization effects, which are writes to an object's state while it is being constructed, and quiescing fields, which are fields that are never written after an object is constructed. We also present a novel taxonomy of degrees of method purity in object-oriented programs, which characterizes methods whose effects are confined to their receiver object. Finally, we find significant amounts of mostly-functional behavior in realistic Java programs: in the benchmarks we analyzed, between 48-53% of declared fields were identifiable as quiescing and between 24-78% of dynamic field reads were from quiescing fields.
Benton and Fischer present a lightweight type and effect system for Java, which characterises initialisation effects (i.e. writes to object state during construction) and quiesing fields (i.e. fields which are never written after construction) REF .
Mostly-Functional Behavior in Java Programs
VMCAI
Computer Science