I gather you look primarily at J7 and not J6 so I wonder what part of J7 do you use JHS or GTK?
Or do you go for the console? 2011/11/2 Andrew Pennebaker <[email protected]> > Woah. This is a much deeper language than I thought. I expected J to be > like Single Assignment C, or Factor but backwards. > > Cheers, > > Andrew Pennebaker > www.yellosoft.us > > On Wed, Nov 2, 2011 at 3:14 PM, bob therriault <[email protected] > >wrote: > > > Roger, > > > > The other aspect that I find very powerful is that it is that you can > > define what you want the inverse to be using the obverse conjunction > (:.). > > Thus the under conjunction (&.)can be non symmetrical if the programmer > > defines a non-symmetrical inverse when creating a verb. > > > > Cheers, bob > > > > On 2011-11-02, at 12:06 PM, Roger Hui wrote: > > > > > It would not be correct. It signals domain error on a non-invertible > > function. > > > > > > > > > > > > On Wed, Nov 2, 2011 at 11:37 AM, Andrew Pennebaker > > > <[email protected]> wrote: > > >> Would it be correct to say ^:_1 uses memoization? > > >> > > >> If so, when does the memoization happen? Does J memoize the function > to > > be > > >> ^:_1'd as soon as the function is defined, or does J wait to do so > when > > >> ^:_1 is called? > > >> > > >> What does J do if you try to ^:_1 a non-injective function? Does it > just > > >> return the first correct input it encounters? > > >> > > >> Cheers, > > >> > > >> Andrew Pennebaker > > >> www.yellosoft.us > > >> > > >> On Wed, Nov 2, 2011 at 2:23 PM, Roger Hui <[email protected]> > > wrote: > > >> > > >>>> How powerful is J's ^:_1 operator? > > >>> Very. > > >>> > > >>>> How is it implemented? > > >>> Carefully. ☺ It's a giant table look-up. Some of the inverses were > > >>> put in to impress particular people, lying in wait for years. (It > > >>> worked! Worth all the effort and all the waiting because of who it > > >>> was.) > > >>> > > >>> See http://www.jsoftware.com/jwiki/Essays/Under , the raison d'être > > >>> for having inverses. > > >>> > > >>> > > >>> > > >>> On Wed, Nov 2, 2011 at 11:14 AM, Andrew Pennebaker > > >>> <[email protected]> wrote: > > >>>> Fascinating. > > >>>> > > >>>> How powerful is J's ^:_1 operator? How is it implemented? > > >>>> > > >>>> Cheers, > > >>>> > > >>>> Andrew Pennebaker > > >>>> www.yellosoft.us > > >>>> > > >>>> On Wed, Nov 2, 2011 at 10:02 AM, Roger Hui < > [email protected] > > >>>> wrote: > > >>>> > > >>>>> It's better to define functions in the form "F from G" rather than > "G > > >>>>> to F", because then the argument and result would be adjacent to > the > > >>>>> function whose domain/range they are in: > > >>>>> > > >>>>> f =: FfG g > > >>>>> f =: GtF g > > >>>>> > > >>>>> > > >>>>> > > >>>>> On Wed, Nov 2, 2011 at 1:32 AM, Alan Stebbens <[email protected]> > > wrote: > > >>>>>>> How would one parse a hex string back to an integer? > > >>>>>> > > >>>>>> Two ways: > > >>>>>> > > >>>>>> Hard way: > > >>>>>> > > >>>>>> H2D =: [: +/ 16 1 * '0123456789abcdef' I. ] > > >>>>>> H2D 'A0' > > >>>>>> 160 > > >>>>>> > > >>>>>> Easy way: > > >>>>>> > > >>>>>> h2d =: d2h ^:_1 > > >>>>>> h2d 'a0' > > >>>>>> 160 > > >>>>>> h2d d2h i.20 > > >>>>>> 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 > > >>>>>> > > >>>>>> > > >>>>>> > > ---------------------------------------------------------------------- > > >>>>>> For information about J forums see > > >>> http://www.jsoftware.com/forums.htm > > >>>>>> > > >>>>> > > ---------------------------------------------------------------------- > > >>>>> For information about J forums see > > http://www.jsoftware.com/forums.htm > > >>>>> > > >>>> > ---------------------------------------------------------------------- > > >>>> For information about J forums see > > http://www.jsoftware.com/forums.htm > > >>>> > > >>> > ---------------------------------------------------------------------- > > >>> For information about J forums see > http://www.jsoftware.com/forums.htm > > >>> > > >> ---------------------------------------------------------------------- > > >> For information about J forums see > http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > > > For information about J forums see http://www.jsoftware.com/forums.htm > > > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > -- Björn Helgason, Verkfræðingur Fornustekkum II 781 Hornafirði, t-póst: [email protected] gsm: +3546985532 twitter: @flugfiskur http://groups.google.com/group/J-Programming Tæknikunnátta höndlar hið flókna, sköpunargáfa er meistari einfaldleikans góður kennari getur stigið á tær án þess að glansinn fari af skónum /|_ .-----------------------------------. ,' .\ / | Með léttri lund verður | ,--' _,' | Dagurinn í dag | / / | Enn betri en gærdagurinn | ( -. | `-----------------------------------' | ) | (\_ _/) (`-. '--.) (='.'=) ♖♘♗♕♔♙ `. )----' (")_(") ☃☠ ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
