Difference between revisions of "Discus"

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[[Image:Ddc-alpha1-logo.png|DDC|center]]
Disciple is an explicitly lazy dialect of [http://www.haskell.org Haskell] which uses supports destructive update, side effects, type directed field projections and some other useful things.
 
   
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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.
== Disciple vs Haskell ==
 
* Strict [[DDC/EvaluationOrder|EvaluationOrder]] is the default, laziness is introduced explicitly.
 
* All data objects support [[DDC/DestructiveUpdate|DestructiveUpdate]].
 
* Type directed [[DDC/FieldProjections|FieldProjections]] complement type classing.
 
* Supports a try-catch [[DDC/ExceptionMechanism|ExceptionMechanism]]
 
* The [[DDC/TypeSystem|TypeSystem]] ensures that side effects and destructive update play nicely with laziness.
 
   
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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.
Some example [http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/src/NBody-Main.ds code], and it's [http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/nbody.png output].
 
   
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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.
== The Disciplined Disciple Compiler (DDC) ==
 
* Uses a typed core language which includes effect, closure, region and mutability information. ([http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/src/NBody.dump-core-reconstruct.dc 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.
 
* Is in a usable alpha state.
 
   
== Get the Source ==
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== More Information ==
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* Please see http://disciple.ouroborus.net for further information.
Use [http://darcs.net darcs] to get the repo from [http://www.haskell.org haskell.org]
 
darcs get http://code.haskell.org/~benl/disciple-HEAD
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* You can also post in http://groups.google.com/group/disciple-cafe.
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* Or ask in #disciplined on irc.freenode.net
 
Check the [[DDC/ReleaseNotes-Alpha1|ReleaseNotes]] and [http://code.haskell.org/~benl/disciple-HEAD/INSTALL INSTALL] 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@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