Deriving Declarations From Programs

. A constraint-based method for deriving type declarations from program statements is described. The relation between declarations and a correctly typed program can be characterized by means of instance constraints and the present paper describes experiences using constraint solving techniques to synthesize the type declarations inherent in a given program. Such a facility may turn out to be useful from the viewpoint of programming methodology. It may suggests an integration of an experimental and "untyped" style with the higher degree of robustness gained with typed languages. 1 Introduction Type declarations in programming languages are praised because it leads to more robust programs and it is a common observation that many programming errors are detected by the type checker or even by the programmer himself, when he is designing the declarations. On the other hand, it can be argued that the additional burden of writing type declarations does not fit with the fast and experimental ..