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 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.
   
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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.
 
* 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 effects and destructive update play nicely with laziness.
 
   
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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], and it's [http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/nbody.png output].
 
   
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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. ([http://cs.anu.edu.au/people/Ben.Lippmeier/project/disciple/src/NBody.dump-core-reconstruct.dc example])
 
 
* 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
* 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 [http://darcs.net darcs] to get the repo from [http://www.haskell.org haskell.org]
 
darcs get http://code.haskell.org/~benl/disciple-alpha1
 
 
Alternatively, get the source tar-ball from Google code
 
[http://code.google.com/p/disciple/downloads]
 
 
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