Discus

Disciple is an explicitly lazy dialect of Haskell which supports destructive update, computational effects, type directed field projections and allied functional goodness.

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 FurtherReading.

Some example code showing most of the extensions, and its output, core and C-code

The Disciplined Disciple Compiler

• Uses a typed core language which includes effect, closure, region and mutability information.
• This extended type information is used to allow code-transformation style optimizations in the presence of side effects and mutable objects.
• Compiles via standard C99, so is highly portable.
• Tested on linux-{x86, x86_64} and darwin-{x86, x86_64} (tested on 10.5.4)
• Is an active research project, but will compile some programs if you're nice to it.

Get the Source

Get the latest stable release (alpha 1.1) with darcs:

    darcs get http://code.haskell.org/ddc/ddc-alpha

For thrill-seekers, the development branch (which usually builds ok) is:

    darcs get http://code.haskell.org/ddc/ddc-head 

Check the ReleaseNotes and INSTALL and HACKING instructions.

Hackery

• If you've tripped over a bug then please add a New Ticket.
• Or check out the Development Wiki
• You can also post in http://groups.google.com/group/disciple-cafe.
• Or send mail to Ben.Lippmeier (wibble) anu.edu.au
• Or ask in #disciplined on irc.freenode.net