Was thinking of something similar this morning, though simpler to implement
even if tedious. I call it "client side compiling"
the idea is to have a bunch of templates that are filled in by J code on a
socket connection (on same machine), with fairly simple client connection. The
socket process would fill in the templates with provided parameters, and start
a compile, then return binding signature when it is done compiling.
For C, the parameters would be ; function definition ; include section ;
compiler optimizations switches
with the latter 2 optional.
the host language needs to either be able to read j arrays of at least numbers
and characters, and with high desirability, boxes of these, or J can convert
its data into something understandable by host (I think this mostly exists for
C)
The idea is that C code could be dynamically compiled from J while only writing
simple functions, and requiring no knowledge of the ceremony of C (other than
the right include files), and no knowledge of the client side tool chains.
Regarding include files, that could be pre-filled by certain templates for
instance an OPENCL function template.
Maybe J's explicit control. style can be autoconverted to C as well. SHAPE_Y
and such are part of J data that would be silently passed along to C. Default
variables of Y0 (0{:: ]), Y1, Y2... could also be silently available. There
would need to be some type annotation system, but one already exists in J's
foreign function bindings.
The last part is 2.0 features though. Just being able to write a C function in
a 0 : 0 block with some documented J like macros would be pretty useful.
----- Original Message -----
From: Raul Miller <[email protected]>
To: Programming forum <[email protected]>
Cc:
Sent: Monday, August 4, 2014 3:39:37 PM
Subject: Re: [Jprogramming] Memoizing (Project Euler problem 14)
It probably would be nice to have something like an ML-flavored compiler
for some subset of J.
J already lets you link to freshly built shared objects (also known as
"DLLs") using 15!: so all the next step is probably for someone to build a
suitably small example implementation.
There's actually a huge variety of such tools. They accumulate faster than
most people can study them. Fortunately, no one needs to use most of their
features - especially for starting projects.
Thanks,
--
Raul
On Mon, Aug 4, 2014 at 3:30 PM, Alex Giannakopoulos <[email protected]
> wrote:
> Hm, interesting approach, that of Roger's, I still haven't digested it all,
> but sometimes it would be nice to be able to tackle these problems the same
> as everybody else in the world...
>
>
> On 4 August 2014 20:12, Alex Giannakopoulos <[email protected]>
> wrote:
>
> > I used the following memoized code,
> >
> > nextcol =: 3 : 0
> >
> > if. 0=2|y do. -: y
> >
> > else. >: 3*y
> >
> > end.
> >
> > )
> >
> >
> > colchain =: 3 : 0 M.
> >
> > if. y=2 do. 1,2
> >
> > else. chain=. colchain nextcol y
> >
> > (>:0{chain),x:y>.1{chain
> >
> > end.
> >
> > )
> >
> > but it took forever to generate the following I aborted it.
> > colchain"0 (2}.i.1000001)
> >
> > I wonder if I did something wrong.
> > It seems to work if, for instance, you give
> > colchain"0 (2+i.9999)
> > Which makes me think the memoization isn't working
> > Even my slow Scheme interpreter gives the answer in 10 seconds or so, C++
> > in less than a second.
> >
> >
> > OTOH, old hands say that J isn't really meant for recursion. I wonder if
> > this problem should be tackled differently.
> >
> > OK, I'm off to read Roger's post that Dan pointed to...
> >
> >
> >
> > On 4 August 2014 17:30, mvillarino <[email protected]> wrote:
> >
> >> 2014-08-04 14:12 GMT+02:00 Dan Bron <[email protected]>:
> >> > If you're OK with spoilers, have you seen Roger's Collatz Conjecture
> >> essay
> >> > on the Wiki?
> >> >
> >> > http://jsoftware.com/jwiki/Essays/Collatz%20Conjecture
> >> >
> >>
> >> ? I googled for information on a J spoiler... but no, I haven't found
> it.
> >> Thanks a lot !!!
> >> ----------------------------------------------------------------------
> >> For information about J forums see http://www.jsoftware.com/forums.htm
> >>
> >
> >
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
>
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