An extension of Hope implemented in the Alvey Flagship project at Imperial College. Hope+ has vectors, real numbers, best fit pattern matching, lazy data constructors, absolute set abstractions and constraints. It has a continuation-based I/O system with referential transparency and is capable of handling all common I/O tasks such as terminal and file I/O, signal handling and interprocess communications. It has modules and separate compilation.
["Hope+", N. Perry, Imperial College, IC/FPR/LANG/2.5.1/7, 1988.]