Discus

Disciple is an explicitly lazy dialect of Haskell which supports destructive update, computational effects, type directed field projections and some other useful things.

Disciple vs Haskell

• Strict EvaluationOrder is the default, laziness is introduced explicitly.
• Type directed FieldProjections complement type classing.
• All data objects support DestructiveUpdate.
• The EffectSystem tracks what computational effects are being used in a program, without the need for state monads.
• The ClassSystem ensures that effects and destructive update play nicely with laziness.
• ClosureTyping is used to track data sharing, and to preserve soundness in the presence of PolymorphicUpdate.

Some example code, and it's output.

The Disciplined Disciple Compiler

• Uses a typed core language which includes effect, closure, region and mutability information. (example)
• This extended type information is used to allow code-transformation style optimizations in the presence of side effects and mutable objects.
• Produces standard C99, so is highly portable.
• Compiles cleanly on linux-x86 and darwin-x86 (tested on Mac OS X 10.5.2)
• Is in a usable alpha state.

Get the Source

Use darcs to get the repo from haskell.org

   darcs get http://code.haskell.org/~benl/disciple-alpha1

Alternatively, download the source tar-ball from Google code

   http://code.google.com/p/disciple/downloads

Check the ReleaseNotes and INSTALL instructions.

Contact the Maintainers

• If you've tripped over a bug then please add it to the Issues List.
• You can also post in http://groups.google.com/group/disciple-cafe
• Or send mail to Ben.Lippmeier@anu.edu.au