[Haskell-cafe] Haskell, Queries and Monad Comprehension

[Torsten Grust]

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.grust at uni-tuebingen.de |
  |                              www-db.informatik.uni-tuebingen.de |
  |               Database Systems - Universität Tübingen (Germany) |