Difference between revisions of "Discus"

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[[Image:Ddc-alpha1-logo.png|DDC|center]]
 
[[Image:Ddc-alpha1-logo.png|DDC|center]]
   
Disciple is an explicitly lazy dialect of [http://www.haskell.org Haskell] which supports destructive update, computational effects, type directed field projections and allied functional goodness.
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Disciple is a dialect of Haskell that uses strict evaluation as the default and supports destructive update of arbitrary data structures. Disciple includes region, effect and closure typing, and this extra information provides a handle on the operational behaviour of code that isn't available in other languages.
   
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Programs can be written in either a pure/functional or effecful/imperative style, and one of our goals is to provide both styles coherently in the same language. The two styles can be mixed safely, for example: when using laziness the type system guarantees that computations with visible side effects are not suspended. Many Haskell programs are also Disciple programs, or will run with minor changes.
== Disciple vs Haskell ==
 
* Strict [[DDC/EvaluationOrder|EvaluationOrder]] is the default, laziness is introduced explicitly.
 
* Type directed [[DDC/FieldProjections|FieldProjections]] complement type classing.
 
* All data objects support [[DDC/DestructiveUpdate|DestructiveUpdate]].
 
* The [[DDC/EffectSystem|EffectSystem]] tracks what computational effects are being used in a program, without the need for state monads.
 
* The [[DDC/ClassSystem|ClassSystem]] ensures that effects and destructive update play nicely with laziness.
 
* [[DDC/ClosureTyping|ClosureTyping]] is used to track data sharing, and to preserve soundness in the presence of [[DDC/PolymorphicUpdate|PolymorphicUpdate]].
 
* Some [[DDC/FurtherReading|FurtherReading]].
 
   
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DDC is still in the "research prototype" stage, meaning that it will compile programs if you are nice to it, but expect compiler panics and missing features. You'll get panics due to ungraceful handling of errors in the source code, but valid programs should compile ok.
Some example [http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/src/NBody-Main.ds code] showing most of the extensions, and its [http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/nbody.png output],
 
[http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/src/NBody.dump-core-reconstruct.dc core] and [http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/src/NBody.ddc.c C-code]
 
   
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== More Information ==
== The Disciplined Disciple Compiler ==
 
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* Please see http://disciple.ouroborus.net for further information.
* Uses a typed core language which includes effect, closure, region and mutability information.
 
 
* You can also post in http://groups.google.com/group/disciple-cafe.
* This extended type information is used to allow code-transformation style optimizations in the presence of side effects and mutable objects.
 
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* Or ask in #disciplined on irc.freenode.net
* Compiles via standard C99, so is highly portable.
 
* Compiles cleanly under linux-{x86, x86_64} and darwin-{x86, x86_64} (tested on 10.5.4)
 
* Is in a usable alpha state.
 
 
== Get the Source ==
 
Get the latest stable release (alpha 1.1) with [http://darcs.net 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
 
 
Alternatively, download the source tar-ball from Google code
 
[http://code.google.com/p/disciple/downloads http://code.google.com/p/disciple/downloads]
 
 
Check the [[DDC/ReleaseNotes-Alpha1.1|ReleaseNotes]] and [http://code.haskell.org/ddc/ddc-head/INSTALL INSTALL] and [http://code.haskell.org/ddc/ddc-head/doc/HACKING HACKING] instructions.
 
 
== Contact the Maintainers ==
 
* If you've tripped over a bug then please add it to the [http://code.google.com/p/disciple/issues Issues List].
 
* You can also post in http://groups.google.com/group/disciple-cafe
 
* Or send mail to Ben.Lippmeier (wibble) anu.edu.au
 

Revision as of 12:33, 3 December 2010

DDC

Disciple is a dialect of Haskell that uses strict evaluation as the default and supports destructive update of arbitrary data structures. Disciple includes region, effect and closure typing, and this extra information provides a handle on the operational behaviour of code that isn't available in other languages.

Programs can be written in either a pure/functional or effecful/imperative style, and one of our goals is to provide both styles coherently in the same language. The two styles can be mixed safely, for example: when using laziness the type system guarantees that computations with visible side effects are not suspended. Many Haskell programs are also Disciple programs, or will run with minor changes.

DDC is still in the "research prototype" stage, meaning that it will compile programs if you are nice to it, but expect compiler panics and missing features. You'll get panics due to ungraceful handling of errors in the source code, but valid programs should compile ok.

More Information