Nice! That said,here are some untested ideas for alternative implementations.
First, 1!:1 and 1!:2 are nicely modular, but if you want high performance the apl shared variable concept (visible in J's mapped files) can give you higher performance. For an "inverted file" (or "table implemented as a named list of columns), it would be tempting to implement this as: A top level structural file, defining the columns, and one file for each column (all using the same name prefix, to slightly reduce the tedium of potential manual recovery work). You lose slightly with the overhead of opening those files, but if speed matters and you have a lot of data you gain from not having to read whichever columns are currently irrelevant. That said, there are a variety of other optimization techniques you can apply to this kind of system when you run into performance issues. Thanks, -- Raul On Thu, Dec 26, 2013 at 11:15 PM, John Baker <[email protected]> wrote: > I've put up some more goodies in jacks. dbi.ijs is a simple inverted file > system that can be shared with companion APL and C# systems. > > http://bakerjd99.wordpress.com/2013/12/26/apl-software-archaeology-dbi-edition/ > > Check out the APL character Christmas tree - latex generated. > > > On Mon, Dec 23, 2013 at 1:29 PM, John Baker <[email protected]> wrote: > >> Jurkey - a cross of J and turkey yielding something like jerky. I like it. >> Cheers >> >> >> On Mon, Dec 23, 2013 at 8:56 AM, Y-01 <[email protected]> wrote: >> >>> John, thanks for your J-turkey for Christmas. >>> >>> >>> On Sat, Dec 21, 2013 at 11:54 PM, John Baker <[email protected]> wrote: >>> >>> > I have set up a GitHub repo that consolidates all the J code referenced >>> on >>> > ADND. For more check: >>> > >>> > http://bakerjd99.wordpress.com/2013/12/21/jacks-repository/ >>> > >>> > Merry Christmas worldwide J'ugglers. You guys/gals consistently produce >>> the >>> > most interesting email in my inboxes. >>> > >>> > -- >>> > John D. Baker >>> > [email protected] >>> > ---------------------------------------------------------------------- >>> > For information about J forums see http://www.jsoftware.com/forums.htm >>> > >>> ---------------------------------------------------------------------- >>> For information about J forums see http://www.jsoftware.com/forums.htm >>> >> >> >> >> -- >> John D. Baker >> [email protected] >> > > > > -- > John D. Baker > [email protected] > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
