- template-haskell - Haskell.org

Re: [Template-haskell] types.
by Keean Schupke 20 Feb '05

20 Feb '05

Last mail seemed to get lost (think I forgot to CC it to the list): would this work with: $(something [d| f a = a + 1 |]) Such that I can reference the reified type of 'f' from inside 'something'. 'something' would be imported from another file. I am using ghc-6.4 Keean. Sean Seefried wrote: > > On 18/02/2005, at 8:11 PM, Keean Schupke wrote: > >> Is it possible to get at type information from TH? I am thinking of >> something >> like the following: >> >> f a = a + 1 >> >> {- ghc derives the type: f :: Integral a => a -> a -} >> >> Can I get at this derives type information? It would be very useful >> for the project I am working on... can I just reify the type of the >> function? >> > > The answer to this question is a little tricky - it's yes with a few > caveats. Firstly, the Q monad can be "run" in two contexts - within > the IO monad and with in the TcM monad of the GHC compiler. You can't > you `reify' to get type information in the former context. > Secondly, you can only reify the type of something that has been > imported from another module. No go on the reifying something > declared within the module you're reifying in. > > I have two pieces of sample code that demonstrate the Q monad being > run within the TcM monad and within the IO monad. The first one > works, the second doesn't. They are attached. > > These built in an old version of GHC 6.3. They should compile and run > in GHC 6.5 without *too* much difficulty although I haven't tested it. > > Cheers, > > Sean >

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types.
by Keean Schupke 18 Feb '05

18 Feb '05

Is it possible to get at type information from TH? I am thinking of something like the following: f a = a + 1 {- ghc derives the type: f :: Integral a => a -> a -} Can I get at this derives type information? It would be very useful for the project I am working on... can I just reify the type of the function? Keean.

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parse to THSyntax
by WANG Meng 28 Jan '05

28 Jan '05

Hi All, I am trying to develop a Haskll like DSEL using template haskell. I am just wondering whether there is any parser built to parse Haskell source to THSnytax? -W-M- @ @ | \_/

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RE: [Template-haskell] example of derive using Template Haskell?
by Simon Peyton-Jones 24 Jan '05

24 Jan '05

| unfortunately, a LOT has appears to have changed | since 6.2.2. For example, Language.Haskell.TH | doesn't exist in 6.2.2. Instead I have | Language.Haskell.THSyntax. And TyConI doesn't | exist yet either. | | | I'm inclined to believe that moving forward on | Template Haskell with 6.2.2 is pointless. Is | there any way of obtaining a build of 6.3 for | windows (or even better 6.4RC1!)? You may well be right. Template Haskell is in its infancy, relative to most of GHC, and its interface has changed substantially between 6.2 and 6.4. 6.4 will be out in weeks not months. It's our top priority. Simon

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example of derive using Template Haskell?
by S. Alexander Jacobson 20 Jan '05

20 Jan '05

Does [d|...] work in 6.2.2 and if so, how do I enable it? This code gives a syntax error: {-# OPTIONS -fglasgow-exts #-} module Tth where import Language.Haskell.THSyntax import Language.Haskell.Syntax fooFunc = [d|funD "foo" [clause [] (normalB $ litE $ StringL "bar") [] ] |] goo = [|2|] --- {-# OPTIONS -fglasgow-exts #-} import Tth foo = $(goo) $(fooFunc) If I eliminate the d in "[d|" I get an error about Dec conflicting with Exp. I can actually use template Haskell in 6.2.2, can anyone provide an example of deriving a class? -Alex- ______________________________________________________________ S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com

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RE: [Template-haskell] example of derive using Template Haskell?
by Simon Peyton-Jones 17 Jan '05

17 Jan '05

6.4 should be out "soon". I.e. in January I hope. It's hard to finish though! Simon | -----Original Message----- | From: template-haskell-bounces(a)haskell.org [mailto:template-haskell-bounces@haskell.org] On | Behalf Of S. Alexander Jacobson | Sent: 14 January 2005 03:53 | To: Sean Seefried | Cc: template-haskell(a)haskell.org | Subject: Re: [Template-haskell] example of derive using Template Haskell? | | Uhm. Ok, so I guess the question is then... | What is acceptable in 6.2 or is 6.4 coming out | soon? | | -Alex- | | On Fri, 14 Jan 2005, Sean Seefried wrote: | | > | > On 14/01/2005, at 7:22 AM, S. Alexander Jacobson wrote: | > | >> This is really great. Do you have an example of use of each of these | >> functions? | >> | >> e.g. do I do: | >> | >> $(derive [Int,String,MyTime]) | >> or | >> | >> $(derive ["Int","String","MyTime"]) | > | > Oh dear, I've just realised a problem. This code only works with GHC 6.3. | > Template Haskell has changed a lot since GHC 6.2. | > | > What you should type is | > | > $(derive [ ''Int, ''String, ''MyTime ]) | > | > The '' syntax means "get the name of this type". There is also a single quote | > syntax ' which means "get the name of this variable". This is new syntax | > introduced with Template Haskell. | > | > Sean | > | > | | ______________________________________________________________ | S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com | _______________________________________________ | template-haskell mailing list | template-haskell(a)haskell.org | http://www.haskell.org/mailman/listinfo/template-haskell

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CfC: GPCE'05 - Generative Programming and Component Engineering
by Eelco Visser 06 Jan '05

06 Jan '05

FIRST CALL FOR CONTRIBUTIONS ---------------------------------------------------------------------- 4th International Conference on Generative Programming and Component Engineering (GPCE'05) Sep 29 - Oct 1, 2005, Tallinn (Estonia) http://www.gpce.org/05 Sponsored by ACM SIGPLAN, in cooperation with ACM SIGSOFT co-located with ICFP'05 and TFP'05 ---------------------------------------------------------------------- Consult http://www.gpce.org/05 for UP-TO-DATE and DETAILED information AVAILABLE: Calls for WORKSHOP and TUTORIAL PROPOSALS FORTHCOMING: Calls for papers and demonstrations (by mid January) ---------------------------------------------------------------------- IMPORTANT DATES * Feb 25, 2005: Submission of workshop and tutorial proposals * Mar 18, 2005: Notification for workshop and tutorial proposals * Apr 10, 2005: Submission of abstracts (only for papers) * Apr 15, 2005: Submission of papers and demos * May 30, 2005: Notification for papers and demos * Sep 27-28, 2005: GPCE workshops and tutorials * Sep 29 - Oct 1, 2005: GPCE papers and demos ---------------------------------------------------------------------- SCOPE. Generative and component approaches have the potential to revolutionize software development in a similar way as automation and components revolutionized manufacturing. Generative Programming (developing programs that synthesize other programs), Component Engineering (raising the level of modularization and analysis in application design), and Domain-Specific Languages (elevating program specifications to compact domain-specific notations that are easier to write and maintain) are key technologies for automating program development. GPCE arose as a joint conference, merging the conference on Generative and Component-Based Software Engineering (GCSE) and the workshop on Semantics, Applications, and Implementation of Program Generation (SAIG). The goal of GPCE is to provide a meeting place for researchers and practitioners interested in cutting edge approaches to software development. We aim to foster further cross-fertilization between the software engineering research community and the programming languages community, in addition to supporting the original research goals of both the GCSE and the SAIG communities. ---------------------------------------------------------------------- TOPICS. GPCE seeks contributions both in software engineering and in programming languages related (but not limited) to: * Generative programming - Reuse, meta-programming, partial evaluation, multi-stage and multi-level languages, step-wise refinement - Semantics, type systems, symbolic computation, linking and explicit substitution, in-lining and macros, templates, program transformation - Runtime code generation, compilation, active libraries, synthesis from specifications, development methods, generation of non-code artifacts, formal methods, reflection * Generative techniques for - Product lines and architectures - Embedded systems - Model-driven architecture * Component-based software engineering - Reuse, distributed platforms, distributed systems, evolution, analysis and design patterns, development methods, formal methods * Integration of generative and component-based approaches * Domain engineering and domain analysis - Domain-specific languages (DSLs) including visual and UML-based DSLs * Separation of concerns - Aspect-oriented and feature-oriented programming, - Intentional programming and multi-dimensional separation of concerns * Industrial applications ---------------------------------------------------------------------- Contributions to GPCE should belong to the following categories: WORKSHOPS providing intensive collaborative environments, where generative and component technologists meet to discuss (and solve) challenging problems facing the field. TUTORIALS giving a deeper or broader insight than conventional lectures (they are expected to extend over a half or a full day). Tutorials can be on any theme from or related to the topics above: surveys, experience reports or specialized research topics. However, a tutorial is expected to attract a reasonable number of participants (at least 10). PAPERS reporting research results and/or experience related to the topics above (PC co-chairs can advise on appropriateness). We especially encouraged original high-quality reports on applications to real-world problems, relating ideas and concepts from several topics, or bridging the gap between theory and practice. DEMOS covering novel tools, techniques or ideas; work in progress; or proven techniques used in real world scenarios. Demos will be selected based on technical content, practical or academic relevance, and their feasibility w.r.t. the infrastructure locally available. Presentations must focus on the technical content (product marketing would be inappropriate). ---------------------------------------------------------------------- ORGANIZATION General Chair * Eugenio Moggi (Genova University, Italy) Program Committee Chairs * Robert Glueck (University of Copenhagen, Denmark) * Michael Lowry (NASA, USA) Publicity Chair * Eelco Visser (Utrecht University, The Netherlands) Workshops and Tutorials Chairs * Jeff Gray (University of Alabama at Birmingham, USA) * Andrew Malton (Waterloo University, Canada) Local Arrangements Chair * Tarmo Uustalu (Institute of Cybernetics, Tallinn) ----------------------------------------------------------------------

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Template Haskell in 6.4
by Simon Peyton-Jones 23 Dec '04

23 Dec '04

Dear Template Haskell folk I think I've reached the end of my urgent to-do list for Template Haskell in GHC 6.4. Can any of you build the HEAD and try it out? In particular, I think most of the dust has settled on the new Name data type. The worst feature at the moment is that if the programmer constructs an utterly bogus piece of TH syntax, and then splices it in, there's an abysmal error message (emitted by hsSyn/Convert.lhs). The point is that TH.Syntax allows many syntactically ill-formed programs (e.g. putting a forall type in a context) and that simply crashes the conversion from TH.Syntax -> HsSyn What is needed is for someone to take hsSyn/Convert in hand, and give it proper error messages. The conversion process is not unlike the renamer -- it may fail for many programmer reasons, and then it should produce a decent error message. Any volunteers? It's not difficult... Simon

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RE: [Template-haskell] Re: template-haskell names in 6.3
by Simon Peyton-Jones 23 Dec '04

23 Dec '04

Fair point. I'll make them print identically for now, and we can see if anyone has difficulty. Simon | -----Original Message----- | From: template-haskell-bounces(a)haskell.org [mailto:template-haskell-bounces@haskell.org] On | Behalf Of Duncan Coutts | Sent: 22 December 2004 22:35 | To: Simon Peyton-Jones | Cc: template-haskell(a)haskell.org | Subject: RE: [Template-haskell] Re: template-haskell names in 6.3 | | On Tue, 2004-12-21 at 17:05 +0000, Simon Peyton-Jones wrote: | > There is a difference between the result of calling mkName, and a quoted | > name e.g 'map. The former is dynamically bound and the latter is | > lexically bound. | > | > Because there's a difference, I've made them print differently in the | > pretty printer | > | > Foo.baz for the dynamically bound one | > Foo:baz for the lexically scoped one | > | > This might break someone's code. Maybe they should both print as | > "Foo.baz"? | | Since lexically scoped is the normal situation perhaps it should get the | ordinary Foo.baz syntax and the dynamically bound variables should get | the other syntax. | | Actually, for non-qualified variables there is still no syntactic | difference between dynamically and statically scoped ones so it begs the | question of why a syntactic difference is needed for the qualified case | (or perhaps if a syntactic difference in the non-qualified would be a | good idea). | | Duncan | | _______________________________________________ | template-haskell mailing list | template-haskell(a)haskell.org | http://www.haskell.org/mailman/listinfo/template-haskell

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RE: [Template-haskell] Re: template-haskell names in 6.3
by Simon Peyton-Jones 22 Dec '04

22 Dec '04

Dear Template Haskell folk I've now arranged that nameBase (mkName "Foo.baz") == "baz" nameModule (MkName "Foo.baz") == "Foo" as you might expect. There is a difference between the result of calling mkName, and a quoted name e.g 'map. The former is dynamically bound and the latter is lexically bound. Because there's a difference, I've made them print differently in the pretty printer Foo.baz for the dynamically bound one Foo:baz for the lexically scoped one This might break someone's code. Maybe they should both print as "Foo.baz"? There is no Haddock documentation to speak of in the TH libraries. Would someone (Ian?) like to add some? Simon | -----Original Message----- | From: Keean Schupke [mailto:k.schupke@imperial.ac.uk] | Sent: 21 December 2004 15:31 | To: Simon Peyton-Jones | Cc: template-haskell(a)haskell.org | Subject: Re: [Template-haskell] Re: template-haskell names in 6.3 | | It won't make a difference right now, so you can leave it out for now, | but I think it should work... | | Keean. | | Simon Peyton-Jones wrote: | | >aha, that's a good question. | > | >Hmm. It probably ought to work (though it won't today). Would it make | >a difference? | > | >S | > | >| -----Original Message----- | >| From: Keean Schupke [mailto:k.schupke@imperial.ac.uk] | >| Sent: 21 December 2004 14:03 | >| To: Simon Peyton-Jones | >| Cc: template-haskell(a)haskell.org | >| Subject: Re: [Template-haskell] Re: template-haskell names in 6.3 | >| | >| So does this work? | >| | >| nameModule (mkName "Foo.Bar") | >| | >| Keean. | > | > | >

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