[racket] How to view source code of procedures? MIT scheme "pp" equivalent?

I think I have a much simpler approach for my purposes.  I can have a
(define-expression ...) macro that basically just stores the expression as
a quoted list.  This largely emulates c#'s expression trees, but with a lot
less hassle and ugly syntax.  I can then achieve the composition I desire
through quasiquoting/unquoting the expressions.  ie,

`(lambda (x) (and (> x 3) ,(some-other-expression x)))

I can then inspect the expression and translate it accordingly for various
source data (sql, xpath, files, vectors), etc.

A reread of
http://homepages.inf.ed.ac.uk/slindley/papers/practical-theory-of-linq.pdf
shows
that basically all they are doing is quoting and unquoting expressions and
then normalizing them for a particular runtime target.  Through this you
can achieve a lot of the composition and parametrization of queries that is
sorely lacking in sql.

I'll keep you posted, most likely via random SOS pings to this list :).

Thanks.


On Sun, Dec 29, 2013 at 10:16 AM, Matthias Felleisen
<matthias at ccs.neu.edu>wrote:

>
> On Dec 28, 2013, at 2:01 PM, Scott Klarenbach wrote:
>
> I'm playing around with the idea of a sort of "Language Integrated Query"
> like LINQ.  For example:
>
> > (sql (query 'my-table
>      #:where (λ (row) (> (hash-ref row 'id) 3))))
> "select * from my-table where id > 3"
>
>
> I understand your motivation now. See Greg's suggestions. I think they are
> right on.
>
> In another thread, I'd like to poll this list as to the benefits (if any)
> of such a linq-style approach.  I got inspired by this paper:
> http://homepages.inf.ed.ac.uk/slindley/papers/practical-theory-of-linq.pdf and
> really enjoyed the c# linq stuff I've played around with.  It may very well
> be; however, that this is not desired or useful,
>
>
>
> (1) Part of the Racket philosophy is not to exclude some approach because
> it is not desired or not considered useful. We welcome experimentations
> such as yours and when things fail, we re-consider our language. (No
> promise that we change it :-)
> (2) I think a DSL approach to DBs based on syntactic abstractions might be
> more useful.
>
> Keep us posted. Better yet, report on your experience at the next
> RacketCon.
>
>
>
> As an aside:
>
>
>> This might be a MIT misunderstanding about the relationship between
>> Scheme and the lambda calculus. It is certainly not possible in general and
>> I see no pragmatic use case for an approximation.
>>
>
> It would be really nice to print the source code of a known procedure on
> the repl, in order to get a quick view of what it does.  Or, the "pa"
> function which prints out the arguments of a procedure is even more useful.
>
>
>
> I think a function that displays (1) docs and/or (2) specs (say contracts)
> might be a lot more useful than raw source.
>
> -- Matthias
>
>
>
>


-- 
Talk to you soon,

Scott Klarenbach

PointyHat Software Corp.
www.pointyhat.ca
p 604-568-4280
e scott at pointyhat.ca
200-1575 W. Georgia
Vancouver, BC V6G2V3

_______________________________________
To iterate is human; to recur, divine
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