Programming with Partially Specified Collections

Enumerated collections (e.g. lists, sets, etc.) provided by programming languages are usually defined by completely and precisely enumerating all their constituent elements. Conversely, in (constraint) logic programming languages it is common to deal with partially specified collections where either some elements or some parts of the collection are left unknown. In this paper we claim that partially specified collections (in particular, lists and sets) can be conveniently exploited in a wider setting, even in the context of more conventional languages using a library-based approach. We prove this claim by showing a number of simple examples using Java and the Java library JSetL.