Yes, that was intended to be a simple, meaningful example of f@g@h -- and a
concise example of how the "Simple J" rules can make some things awkward.
(But it's hardly the only thing made awkward -- consider inner product as
another concise example.)
--
Raul
On Wed, Dec 7, 2011 at 5:30 AM, Linda Alvord <lindaalv...@verizon.net>wrote:
> Here's the message.
>
> Linda
>
> -----Original Message-----
> From: programming-boun...@jsoftware.com [mailto:
> programming-boun...@jsoftware.com] On Behalf Of Raul Miller
> Sent: Tuesday, December 06, 2011 9:29 AM
> To: Programming forum
> Subject: Re: [Jprogramming] Turkey Roll - Challenge 2
>
> require 'strings' NB. require needed for j6, irrelevant for j7
>
> <@toupper@> 'this';'is';'a';'test'
> +----+--+-+----+
> |THIS|IS|A|TEST|
> +----+--+-+----+
>
> Here's an explicit equivalent that does not require rank and does not use @
> a=: toupper 0 {:: 'this';'is';'a';'test'
> b=: toupper 1 {:: 'this';'is';'a';'test'
> c=: toupper 2 {:: 'this';'is';'a';'test'
> d=: toupper 3 {:: 'this';'is';'a';'test'
> a;b;c;d
> +----+--+-+----+
> |THIS|IS|A|TEST|
> +----+--+-+----+
>
> That said, note that 'require rank' is a confusing phrase. Any use of J
> verbs or nouns requires rank, since every J verb has a verb rank and every
> J noun has a noun rank. However, since this interpretation is too
> restrictive, I have presumed that you meant 'does not use the rank
> conjunction'.
>
> --
> Raul
>
> 2011/12/6 Linda Alvord <lindaalv...@verizon.net>
>
> > Can you make a simple example that looks like this u@v@w ? Please use
> > actual verbs so that it is a tight little nugget that might come about
> in a
> > fairly simple mathematical situation. Use it in a situation that does not
> > require rank. Next, write it in explicit form without @
> >
> > Here's what I would like. Remember foo ?
> >
> > foo=: 13 :'an expression with x's and y's and three verbs like # , %:
> ,
> > ? or * '
> >
> >
> > Also:
> >
> > Let us use [: u v or u@:v as we like, and specify a rank when we
> > need one.
> >
> > I think I could live with:
> >
> > Let us use [: u v unless rank is involved. Only use u@:v if rank
> is
> > needed, thus @ vanishes from the planet.
> >
> >
> > Linda
> >
> >
> > -----Original Message-----
> > From: programming-boun...@jsoftware.com
> > [mailto:programming-boun...@jsoftware.com] On Behalf Of Henry Rich
> > Sent: Monday, December 05, 2011 10:08 PM
> > To: Programming forum
> > Subject: Re: [Jprogramming] Turkey Roll - Challenge 2
> >
> > If you are OK with @: , then we agree. @ is hard for beginners.
> >
> >
> > u@v is equivalent to u@:v"v or ([: u v)"v
> >
> > u@v@w is u@:v"v@:w"w or ([: ([: u v)"v w)"w
> >
> > Henry Rich
> >
> > On 12/5/2011 9:57 PM, Linda Alvord wrote:
> > > Can you make a simple example that looks like this u@v@w . Is it
> > possible
> > > to write an explicit version that will create a tacit expression to do
> > the
> > > same thing?
> > >
> > > I don't have a problem with @: . My concern is only with @
> > >
> > > Linda
> > >
> > > -----Original Message-----
> > > From: programming-boun...@jsoftware.com
> > > [mailto:programming-boun...@jsoftware.com] On Behalf Of Henry Rich
> > > Sent: Monday, December 05, 2011 9:28 PM
> > > To: Programming forum
> > > Subject: Re: [Jprogramming] Turkey Roll - Challenge 2
> > >
> > > I don't understand why u@v is anything other than 'right to left'. It
> > > means do v, then do u. u@v@w means w, then v, then u.
> > >
> > > The complication of @ is not its ordering, it's its rank. In my
> classes
> > > I teach @: as a primitive. We don't use [:, or @ .
> > >
> > > Henry Rich
> > >
> > > On 12/5/2011 9:15 PM, Linda Alvord wrote:
> > >>
> > >> Compare your expression for dice :
> > >>
> > >> faces=: {&' o'@((i.3 3)e.&":"1])&.>4 80 840 8620 86420 865320
> > >> faces
> > >> ------T-----T-----T-----T-----T-----┐
> > >> │ │o │o │o o│o o│o o│
> > >> │ o │ │ o │ │ o │o o│
> > >> │ │ o│ o│o o│o o│o o│
> > >> L-----+-----+-----+-----+-----+------
> > >>
> > >> With Kip Murray's version:
> > >>
> > >> one =: ' ',' o ',:' '
> > >> two =: 'o ',' ',:' o'
> > >> three =: 'o ',' o ',:' o'
> > >> four =: 'o o',' ',:'o o'
> > >> five =: 'o o',' o ',:'o o'
> > >> six =: 'o o','o o',:'o o'
> > >> ]dice =: one;two;three;four;five;six
> > >> ----T---T---T---T---T---┐
> > >> │ │o │o │o o│o o│o o│
> > >> │ o │ │ o │ │ o │o o│
> > >> │ │ o│ o│o o│o o│o o│
> > >> L---+---+---+---+---+----
> > >>
> > >> Your dice are great looking! However that change has greatly increased
> > the
> > >> complexity of the code. Also, there is a condition of the challenge
> to
> > >> exclude @ in each expression. This requirement encourages
> considering
> > > the
> > >> execution from the right toward the left. In your example 4 80 840
> > 8620
> > >> 86420 865320 could be puzzling to a beginner. Your other ideas are
> > >> thoughtful ideas to incorporate in an actual design of a program. At
> > this
> > >> stage, I'm trying to raise issues that can be discussed and explored
> > >> further.
> > >>
> > >> From your design so far, is it possible for you to capture the
> actual
> > > values
> > >> of the and display them following each toss ? It is this data
> that
> > > will
> > >> be useful as you finish the challenge.
> > >>
> > >> Linda
> > >>
> > >>
> > >> -----Original Message-----
> > >> From: programming-boun...@jsoftware.com
> > >> [mailto:programming-boun...@jsoftware.com] On Behalf Of Raul Miller
> > >> Sent: Monday, December 05, 2011 9:50 AM
> > >> To: Programming forum
> > >> Subject: Re: [Jprogramming] Turkey Roll - Challenge 2
> > >>
> > >> Personally, I have been baffled by a number of the choices and
> > > requirements
> > >> here. And, by this, I mean that I do not understand them.
> > >>
> > >> That said, here is my current interpretation of a mix of some of the
> > >> statements expressed here, about what is being accomplished:
> > >>
> > >> faces=: {&' o'@((i.3 3)e.&":"1])&.>4 80 840 8620 86420 865320
> > >> toss=: (] {~ (?@$ #)) ".bind 'faces'
> > >>
> > >> Example use, with ascii box drawing enabled:
> > >>
> > >> toss 2 10
> > >> +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> > >> |o |o |o o|o |o |o |o |o o|o o|o o|
> > >> | o | o | o | o | o | | | | o |o o|
> > >> | o| o|o o| o| o| o| o|o o|o o|o o|
> > >> +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> > >> |o |o o|o |o o|o o|o |o |o |o o|o |
> > >> | o | o | | o | | | | | | |
> > >> | o|o o| o|o o|o o| o| o| o|o o| o|
> > >> +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> > >> toss 2 10
> > >> +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> > >> |o |o |o o|o |o o|o |o o|o o|o o|o |
> > >> | | | | o |o o| o | | o |o o| |
> > >> | o| o|o o| o|o o| o|o o|o o|o o| o|
> > >> +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> > >> |o o|o |o o|o o|o o|o o| |o o|o o|o o|
> > >> | | | o | | | o | o | | | |
> > >> |o o| o|o o|o o|o o|o o| |o o|o o|o o|
> > >> +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+
> > >>
> > >> Notes:
> > >>
> > >> 1. I spaced my pips out wider, horizontally, than the original. I
> think
> > >> this looks better.
> > >> 2. toss has 'faces' as an implicit dependency
> > >> 3. I can change the number of dice being tossed by changing the
> argument
> > > to
> > >> toss
> > >>
> > >> In my opinion, this is not a very good design. In "real life" code, I
> > >> would either replace (". bind 'faces') with (faces) or I would make it
> > an
> > >> argument to the function.
> > >>
> > >> I could probably compress a few characters out of the definition of
> > faces,
> > >> but it would become more mysterious if I did so.
> > >>
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