Re: [Haskell-cafe] Haskell, Queries and Monad Comprehension
I would be intrested in seeing this! Could you paste or upload it somewhere? 2010/5/24 C. McCann c...@uptoisomorphism.net: 2010/5/23 Günther Schmidt gue.schm...@web.de: is there anybody currently using Haskell to construct or implement a query language? I've a half-baked, type-indexed (in HList style) implementation of relational algebra lying around somewhere, if that counts as a query language. I was experimenting with using it as a sort of abstract collection interface, which actually worked rather nicely I think, but I didn't have time to flesh it out completely. In particular, only very simple queries and limited kinds of relation composition were supported. Definitely just toy code, though, and dreadfully inefficient; if you're looking for an actual implementation meaning usable interface to an external persistence layer then disregard this. - C. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell, Queries and Monad Comprehension
Günther, On May 24, 2010, at 03:20 , Günther Schmidt wrote: Hi all, is there anybody currently using Haskell to construct or implement a query language? I have read a couple of papers on Monad Comprehension Calculus and similar but none using Haskell nor any other existing programming language to build an actual implementation. Most papers give some sort of Pseudo code, but I couldn't find any meat. we are currently underway building the second version (as in: done right this time) of Ferry, a query compiler that (1) accepts queries over ordered, nested lists, (2) compiles these queries into an intermediate algebraic form, then (3) emits (small bundles of) SQL queries that evaluate the input query over your off-the-shelf RDBMS. We've used Ferry's first version to build new LINQ to SQL providers for Microsoft's LINQ as well as a new code generator for Phil Wadler's Links. The Ferry compiler itself is built in Haskell. Surf to www.ferry-lang.org for more information, screencasts, papers, talks, and contact us for more details. We will be happy to share Ferry's Haskell code once in digestable shape (soon). Cheers, --Torsten -- | Prof. Dr. Torsten Grust torsten.gr...@uni-tuebingen.de | | www-db.informatik.uni-tuebingen.de | | Database Systems - Universität Tübingen (Germany) | ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell, Queries and Monad Comprehension
Hello Torsten, well thank you for taking the time and answering that. It seems that the one thing I am good for, as far as contributions to this list go, is coaxing answers out of our Functional Pros. :) That is good news then, I was getting frustrated reading fantastic papers which eventually were nothing more than teasers. So, will Ferry then be usable from within Haskell? Best regards Günther Am 25.05.10 21:28, schrieb Torsten Grust: Günther, we are currently underway building the second version (as in: done right this time) of Ferry, a query compiler that (1) accepts queries over ordered, nested lists, (2) compiles these queries into an intermediate algebraic form, then (3) emits (small bundles of) SQL queries that evaluate the input query over your off-the-shelf RDBMS. We've used Ferry's first version to build new LINQ to SQL providers for Microsoft's LINQ as well as a new code generator for Phil Wadler's Links. The Ferry compiler itself is built in Haskell. Surf to www.ferry-lang.org for more information, screencasts, papers, talks, and contact us for more details. We will be happy to share Ferry's Haskell code once in digestable shape (soon). Cheers, --Torsten On May 24, 2010, at 03:20 , Günther Schmidt wrote: Hi all, is there anybody currently using Haskell to construct or implement a query language? I have read a couple of papers on Monad Comprehension Calculus and similar but none using Haskell nor any other existing programming language to build an actual implementation. Most papers give some sort of Pseudo code, but I couldn't find any meat. Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell, Queries and Monad Comprehension
Hi Günther, On May 25, 2010, at 21:37 , Günther Schmidt wrote: Hello Torsten, well thank you for taking the time and answering that. It seems that the one thing I am good for, as far as contributions to this list go, is coaxing answers out of our Functional Pros. :) That is good news then, I was getting frustrated reading fantastic papers which eventually were nothing more than teasers. So, will Ferry then be usable from within Haskell? Ferry is much more about the compilation of queries (over list-based data models) than the invention of some new query syntax. We thus are mostly after embeddings of queries into existing host languages. Such embeddings exist for -- C#(Ferry-based LINQ to SQL) -- Links (new Ferry-based SQL code generator) -- Ruby (in the works, provides a much richer and arguably more seamless embedding of queries over Ruby arrays as well as relational tables than does ARel or ActiveRevord's find_by* methods). There's some interesting connection between the compilation techniques employed by Ferry and Data Parallel Haskell. I talked to Simon Peyton Jones and he suggested to attempt a Haskell embedding. So, Haskell: not yet. But conceivable. Cheers, --Torsten Am 25.05.10 21:28, schrieb Torsten Grust: Günther, we are currently underway building the second version (as in: done right this time) of Ferry, a query compiler that (1) accepts queries over ordered, nested lists, (2) compiles these queries into an intermediate algebraic form, then (3) emits (small bundles of) SQL queries that evaluate the input query over your off-the-shelf RDBMS. We've used Ferry's first version to build new LINQ to SQL providers for Microsoft's LINQ as well as a new code generator for Phil Wadler's Links. The Ferry compiler itself is built in Haskell. Surf to www.ferry-lang.org for more information, screencasts, papers, talks, and contact us for more details. We will be happy to share Ferry's Haskell code once in digestable shape (soon). Cheers, --Torsten On May 24, 2010, at 03:20 , Günther Schmidt wrote: Hi all, is there anybody currently using Haskell to construct or implement a query language? I have read a couple of papers on Monad Comprehension Calculus and similar but none using Haskell nor any other existing programming language to build an actual implementation. Most papers give some sort of Pseudo code, but I couldn't find any meat. Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe -- | Prof. Dr. Torsten Grust torsten.gr...@uni-tuebingen.de | | www-db.informatik.uni-tuebingen.de | | Database Systems - Universität Tübingen (Germany) | ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell, Queries and Monad Comprehension
On Mon, May 24, 2010 at 03:20:41AM +0200, Günther Schmidt wrote: Hi all, is there anybody currently using Haskell to construct or implement a query language? Do you mean, HaskellDB? Cheers, -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Haskell, Queries and Monad Comprehension
2010/5/23 Günther Schmidt gue.schm...@web.de: is there anybody currently using Haskell to construct or implement a query language? I've a half-baked, type-indexed (in HList style) implementation of relational algebra lying around somewhere, if that counts as a query language. I was experimenting with using it as a sort of abstract collection interface, which actually worked rather nicely I think, but I didn't have time to flesh it out completely. In particular, only very simple queries and limited kinds of relation composition were supported. Definitely just toy code, though, and dreadfully inefficient; if you're looking for an actual implementation meaning usable interface to an external persistence layer then disregard this. - C. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Haskell, Queries and Monad Comprehension
Hi all, is there anybody currently using Haskell to construct or implement a query language? I have read a couple of papers on Monad Comprehension Calculus and similar but none using Haskell nor any other existing programming language to build an actual implementation. Most papers give some sort of Pseudo code, but I couldn't find any meat. Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
