Status of ScalaQL?

Dmitry,

On the one hand I have to mention that the ScalaQL prototype [1] is not
ready for everyday use, while at the same time I want to stress that the
ideas behind ScalaQL seem more appropriate than ever. Not an easy task to
draft this reply.

There is no technical roadblock to making ScalaQL a fine ORM solution, in
fact work in that direction (but also not ready for every day use) has been
made recently [2]. The limiting factor is the proverbial lack of development
resources for this specialized solution.

I’m quite busy with The Scala Compiler Corner [3], but if I were still a PhD
student, I might consider bringing ScalaQL to the next level (of usability)
and field a paper at the upcoming Intnl Conf on Objects and Databases [4].

Any PhD students reading this thread? ;-)

Miguel

[1] ScalaQL, http://www.sts.tu-harburg.de/people/mi.garcia/ScalaQL

[2] ORM for ScalaQL, http://www.wen-k.com/msc/

[3] http://www.sts.tu-harburg.de/people/mi.garcia/ScalaCompilerCorner

[4] 3rd Intnl Conf on Objects and Databases, http://www.icoodb2010.org/

"Dmitry Grigoriev" wrote in
message news:4B7BB641.80205@dimgel.ru...
> Hello,
>
> The question is probably to Miguel Garcia. I'd like to use ScalaQL in my
> applications, but currently it looks not ready for such usage. You said
> it's just proof of concept and is unsupported. Can you share your future
> plans about it? Thanks.
>

Hi Miguel,

On Wed, Feb 17, 2010 at 9:39 AM, Miguel Garcia wrote:
> I’m quite busy with The Scala Compiler Corner [3]

A very useful resource, of course. The bit about parallelizing the
Scala compiler is quite interesting, I believe that it would improve
productivity a great deal (for people with multi-core machines
anyway). Regarding ""No plans to make javac concurrent that I know
of", I think the following link is more relevant:

http://blogs.sun.com/jjg/entry/towards_a_multi_threaded_javac

Best,
Ismael

Hello Miguel,

Thank you for answering.

> The limiting factor is the proverbial lack of development resources
for this specialized solution.

Unfortunately, I'm neither PhD student nor compiler geek, so I'm not of
much use to you here. Not sure yet, but maybe I'll start digging into
and will be able to contribute as kind of tester or user tutorial
article writer. Would you mind if I'll ask questions in this mailing list?

> [1] ScalaQL, http://www.sts.tu-harburg.de/people/mi.garcia/ScalaQL

You tested it with Scala 2.7.4, I hope I'll be able to use it with
2.7.7, but what about upcoming 2.8?

> Would you mind if I'll ask questions in this mailing list?

Questions help me in figuring out where the sources or documentation can be
improved.

> You tested it with Scala 2.7.4, I hope I'll be able to use it with
> 2.7.7, but what about upcoming 2.8?

The Collections framework was revamped in 2.8, as explained at:

Fighting Bit Rot with Types (Experience Report: Scala Collections)
by Martin Odersky, EPFL and Adriaan Moors, K.U.Leuven.
FSTTCS 2009, IIT Kanpur, India, December 15 to 17, 2009
http://drops.dagstuhl.de/opus/volltexte/2009/2338/pdf/09005.OderskyM.233...

and the ScalaQL prototype depends on an old version of Kiama,
http://code.google.com/p/kiama/ . While Kiama is a great tool for all things
language processing, the functionality used by ScalaQL could be easily
provided by the parser combinators in the Scala library (thus making ScalaQL
easier to configure).

As to LINQ, its syntax hasn't changed since the release of ScalaQL, but the
upcoming C# 4.0 will typecheck some LINQ queries previously deemed
non-valid. C# is for all practical purposes the reference implementation of
LINQ and thus ScalaQL should follow that as "correct LINQ behavior". Both
the C# 3.0 spec and the delta for C# 4.0 can be downloaded from links listed
at http://antlrcsharp.codeplex.com/

In a nutshell, the feature of C# 4.0 that makes for better typing of LINQ is
site-def variance spec, an old trick of Scala. In the delta document, look
for the section containing:

Hello Miguel,

> [1] ScalaQL, http://www.sts.tu-harburg.de/people/mi.garcia/ScalaQL

I attached to this message a small bash script that downloads zip
archives, builds ScalaQL and compiles ScalaQLTest. All-in-one, without
Eclipse. Good alternative to long "How to build the source code"
instruction. Just copy script to empty directory, edit SCALA_HOME inside
it and run it.