Re: [Haskell-cafe] Relational Algebra library: first version on GitHub
Hey Ertugrul, You are absolutely right and the first item on my todo list is to add better examples. Paul On Sun, Jul 22, 2012 at 5:24 AM, Ertugrul Söylemez e...@ertes.de wrote: Hello there Paul, Paul Visschers m...@paulvisschers.net wrote: A couple of weeks ago I asked if there was interest in a library that implements a type-safe relational algebra. The response was positive, so I have spruced up the code I had a bit and created a repository on GitHub at: https://github.com/PaulVisschers/relational-algebra It is a very rudimentary version. The code is not documented and there is only a very basic example database in Test.hs. It might be helpful to look at HaskellDB's PrimQuery and PrimExpr, as this library is mostly a direct copy from that (but typed). I will add some decent examples of expressions and queries shortly. If you check it out, please comment on it and let me know if you want to contribute. Since this is going to be my first release, any feedback is welcome. Well, the demonstration could be a bit more comprehensive. I would be very interested in seeing queries, especially nontrivial ones with joins and such. Would you mind writing a more comprehensive demonstration? Greets, Ertugrul -- Not to be or to be and (not to be or to be and (not to be or to be and (not to be or to be and ... that is the list monad. ___ 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
[Haskell-cafe] Relational Algebra library: first version on GitHub
Hello, A couple of weeks ago I asked if there was interest in a library that implements a type-safe relational algebra. The response was positive, so I have spruced up the code I had a bit and created a repository on GitHub at: https://github.com/PaulVisschers/relational-algebra It is a very rudimentary version. The code is not documented and there is only a very basic example database in Test.hs. It might be helpful to look at HaskellDB's PrimQuery and PrimExpr, as this library is mostly a direct copy from that (but typed). I will add some decent examples of expressions and queries shortly. If you check it out, please comment on it and let me know if you want to contribute. Since this is going to be my first release, any feedback is welcome. Paul Visschers ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Relational Algebra library: first version on GitHub
Hello there Paul, Paul Visschers m...@paulvisschers.net wrote: A couple of weeks ago I asked if there was interest in a library that implements a type-safe relational algebra. The response was positive, so I have spruced up the code I had a bit and created a repository on GitHub at: https://github.com/PaulVisschers/relational-algebra It is a very rudimentary version. The code is not documented and there is only a very basic example database in Test.hs. It might be helpful to look at HaskellDB's PrimQuery and PrimExpr, as this library is mostly a direct copy from that (but typed). I will add some decent examples of expressions and queries shortly. If you check it out, please comment on it and let me know if you want to contribute. Since this is going to be my first release, any feedback is welcome. Well, the demonstration could be a bit more comprehensive. I would be very interested in seeing queries, especially nontrivial ones with joins and such. Would you mind writing a more comprehensive demonstration? Greets, Ertugrul -- Not to be or to be and (not to be or to be and (not to be or to be and (not to be or to be and ... that is the list monad. signature.asc Description: PGP signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Relational Algebra library: first version on GitHub
Great / thanks!!! This will be incredibly helpful for some of my present work. :-) On Saturday, July 21, 2012, Paul Visschers wrote: Hello, A couple of weeks ago I asked if there was interest in a library that implements a type-safe relational algebra. The response was positive, so I have spruced up the code I had a bit and created a repository on GitHub at: https://github.com/PaulVisschers/relational-algebra It is a very rudimentary version. The code is not documented and there is only a very basic example database in Test.hs. It might be helpful to look at HaskellDB's PrimQuery and PrimExpr, as this library is mostly a direct copy from that (but typed). I will add some decent examples of expressions and queries shortly. If you check it out, please comment on it and let me know if you want to contribute. Since this is going to be my first release, any feedback is welcome. Paul Visschers ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Relational Algebra
Hi all, has anybody already developed an EDSL for relational algebra? HaskellDB does that, but its current implementation only allows for generating SQL, are there other implementations? Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Relational Algebra
has anybody already developed an EDSL for relational algebra? HaskellDB does that, but its current implementation only allows for generating SQL, are there other implementations? Hello Günther, Ganesh did something called squiggle a while ago: http://code.haskell.org/squiggle/unstable/ I've done something similar but it's not published or hosted anywhere, so no link. Can upload it to code.haskell.org if you're interested. Both of our projects just generate SQL though, AFAIK. Was there something else you wanted to generate? Alistair ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Relational Algebra
Hi Alistair, Both of our projects just generate SQL though, AFAIK. Was there something else you wanted to generate? I wish I could provide a clear answer to that myself, truth is I'm not certain myself at the moment. All this is related to a rl problem I have, it concerns the business logic of the app I wrote. I hindsight it occurred to me that the algorithm can be abstractly expressed in terms of relational algebra for which I need an EDSL. One concrete implementation could then be an interpreter / compiler to SQL, if I choose to use a database backend, and another implementation could be a interpretor to in-memory data structures (maps, whathaveyou), or a debugger to see if I have got the abstract algorithm right. I had made very good experience with HaskellDB, it was a great help, but the DSL of HaskellDB immediately translates to SQL, it's hardwired to do so. With the newer techniques for designing EDSLs (finally tagless in particular), I'm considering to roll one myself, and I suppose I'll also need HList to do so too. Quite a number of people on this list also use Haskell for rl applications, so I reason that someone must already have tried something similar. Günther ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Relational Algebra post
Cool! That goes on my list for further study. (I have a work-in-progress of something similar for description logics.) #g -- At 15:01 22/10/04 -0700, Brian Beckman wrote: Content-class: urn:content-classes:message Content-Type: multipart/alternative; boundary=_=_NextPart_001_01C4B882.A1CF3A2A on my blog (http://weblogs.asp.net/brianbechttp://weblogs.asp.net/brianbec) , i've posted a couple of Haskell gadgets. One is a simulator for the relational algebra of database theory. The other is just an expansion of one of Paul Hudak's derivations of State monads. ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe Graham Klyne For email: http://www.ninebynine.org/#Contact ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
