Roadmap

Make type-system sound (early Jan)

See #139

Roy's type-system is currently unsound, particularly around the implementation of structural subtyping. The type-system needs to be rewritten to become constraint-based so that subtype constraints can be introduced using row polymorphism.

A WIP branch is here:

https://github.com/pufuwozu/roy/tree/constraints

Add rank-N types (end of Jan)

This will be important for a properly factored standard library. I am not sure how to implement this feature.

Add higher-order modules (end of February)

I've been convinced that polymorphic modules are extremely useful in a purely functional language. For more information on how useful this is:

http://precog.com/blog-precog-2/entry/existential-types-ftw

Write standard library (end of March)

Roy needs a good implementation of The Typeclassopedia. Tony Morris has written one here:

https://github.com/tonymorris/lens-proposal

Add automatic lens generation (end of March)

See #92

Lenses make nested data updating easy. There's no reason why the compiler can't automatically create lenses for user-defined data structures.

See Tony Morris' paper on asymmetric lenses:

http://dl.dropbox.com/u/7810909/media/doc/lenses.pdf