Dictionaries are powerful (if I may, this is the thing I miss most in J).
I recall reading somewhere, that a dictionary is a generalization of a
mapping {X}->{Y}, if Xs are (0..N) then we get an array.
Thus, using array facilities in J when a task calls for a dictionary will
always add a layer of indirection and be cumbersome to a certain degree.
Another thing is that if to add something like this, may be to consider
overloading of { } and friends ( like i. to map values to keys).
regards,
Danil
пн, 18 нояб. 2019 г. в 11:57, Jan-Pieter Jacobs <janpieter.jac...@gmail.com
>:
> Lua (https://www.lua.org) comes to mind:
> A little (~150kB for the windows dll) language which as only composite
> datatype has the table, to be used both as a dictionary, as well as indexed
> array, as well as container for any OOP objects. It appears very mature and
> stable, being used in plenty of big-shot apps like Adobe Lightroom and
> World of Warcraft.
>
> I very much enjoyed its no-nonsense approach when working with it, and it
> has excellent docs (https://www.lua.org/docs.html).
>
> I've always dreamed of having a crossbreed between J and Lua, but I don't
> really have the capabilities nor time too cook up an addon or the like
> implementing an interface.
>
> Maybe someone else wants to?
>
> Jan-Pieter
>
>
>
> On Mon, Nov 18, 2019, 04:29 'Jon Hough' via Programming <
> programm...@jsoftware.com> wrote:
>
> > Since d. /D. are being retired (for derivative usage), why not use them
> > for an inbuilt dictionary type?
> > I think J would be better with some kind of hashmap / dictionary (O(1)
> > lookup time), and d./D. already match
> > the first letter of "dictionary", so it's the perfect fit.
> > On Monday, November 18, 2019, 12:25:27 PM GMT+9, bill lam <
> > bbill....@gmail.com> wrote:
> >
> > key/value dictionary can be done in addon, but I think better
> > implemented in C for efficieny because it contains loops.
> >
> >
> > Sun, 17 Nov 2019, Henry Rich написал(а):
> > > In J I find myself coming back to simple arrays for most data
> structures.
> > >
> > > Trees can be represented as boxes containing subtrees. That works, but
> > is
> > > usually more trouble than simply managing an array.
> > >
> > > Linked lists are used only for efficiency, and in the cases where that
> > > matters you can easily have a list of indexes to an array of data
> items.
> > >
> > > Stacks are just lists, as Devon said.
> > >
> > > The datatype I really want is a directory object that acts as an
> > efficient
> > > and easy-to-use associative memory. You put key/values in and then
> > retrieve
> > > a value by presenting its key. Has anyone written an addon for that?
> > >
> > > (Note: the primitive 128!:8 (create a hash for a noun) was added to
> J9.01
> > > with this in mind)
> > >
> > > Henry Rich
> > >
> > > On 11/17/2019 8:16 PM, 'Bo Jacoby' via Programming wrote:
> > > > I failed to communicate the links before, but here they are. Ordinal
> > fractions are somewhat like infinite-dimensional arrays.
> > > >
> >
> https://www.academia.edu/10031088/ORDINAL_FRACTIONS_-_the_algebra_of_data
> > > >
> > > >
> > > > http://www.statemaster.com/encyclopedia/Ordinal-fraction
> > > > Bo.
> > > >
> > > > Den søndag den 17. november 2019 22.07.28 CET skrev Devon
> > McCormick <devon...@gmail.com>:
> > > > Trees are simple to implement in J -
> > > > https://code.jsoftware.com/wiki/User:Devon_McCormick/Trees - as are
> > graphs
> > > > -
> > > >
> >
> https://code.jsoftware.com/wiki/NYCJUG/2009-11-10/BreadthFirstGraphTraversal
> > > > .
> > > > A stack is simple to implement too but I'm not sure why you would
> want
> > to
> > > > as it's simply a vector with very restrictive rules to manipulate it.
> > > > Linked lists make no sense in a language with dynamic arrays for much
> > the
> > > > same reason since a linked list is mainly a way of implementing
> dynamic
> > > > arrays but has benefit only in a language which lacks these natively.
> > > >
> > > > On Sun, Nov 17, 2019 at 8:24 AM 'Bo Jacoby' via Programming <
> > > > programm...@jsoftware.com> wrote:
> > > >
> > > > > ORDINAL FRACTIONS - the algebra of data
> > > > >
> > > > >
> > > > >
> > > > > |
> > > > > |
> > > > > |
> > > > > | | |
> > > > >
> > > > > |
> > > > >
> > > > > |
> > > > > |
> > > > > | |
> > > > > ORDINAL FRACTIONS - the algebra of data
> > > > >
> > > > > This paper was submitted to the 10th World Computer Congress, IFIP
> > 1986
> > > > > conference, but rejected by the referee....
> > > > > |
> > > > >
> > > > > |
> > > > >
> > > > > |
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Den søndag den 17. november 2019 07.12.02 CET skrev Raul
> Miller
> > <
> > > > > rauldmil...@gmail.com>:
> > > > >
> > > > > Arrays are roughly analogous to computer memory.
> > > > >
> > > > > Put different: I think you are asking the wrong question.
> > > > >
> > > > > (Partially: it's worth thinking about why you pick whichever data
> > > > > structures...)
> > > > >
> > > > > ((It can also sometimes be useful to look on rosettacode for
> > examples of
> > > > > various daya structure handling mechanisms.))
> > > > >
> > > > > Thanks,
> > > > >
> > > > > --
> > > > > Raul
> > > > >
> > > > > On Sat, Nov 16, 2019 at 6:00 PM Jimmy Gauvin <
> jimmy.gau...@gmail.com
> > >
> > > > > wrote:
> > > > >
> > > > > > Hi,
> > > > > >
> > > > > > when dealing with data structures other than arrays such as
> trees,
> > > > > graphs,
> > > > > > stacks, linked lists what other programming language do you
> resort
> > to ?
> > > > > >
> > > > > > Or do stick with J for all endeavours?
> > > > > >
> > > > > >
> > > > > > Jimmy
> > > > > >
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> > > > >
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> >
> > --
> > regards,
> > ====================================================
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