O'Haskell is a programming language derived from Haskell by the addition of concurrent reactive objects and subtyping. Because Haskell already encompasses an advanced type sy...
We extend classical first-order logic with subtyping by type predicates and type coercion. Type predicates assert that the value of a term belongs to a more special type than the ...
In the interest of designing a recursive module extension to ML that is as simple and general as possible, we propose a novel type system for general recursion over effectful expr...
The inclusion of Regular Expressions (REs) is the kernel of any type-checking algorithm for XML manipulation languages. XML applications would benefit from the extension of REs wi...
We show how to implement a calculus with higher-order subtyping and subkinding by replacing uses of implicit subsumption with explicit coercions. To ensure this can be done, a pol...