[Jprogramming] Understandable J

Tue May 20 05:01:06 UTC 2014

is that special code? because its not supposed to work ie:

'see?' # 1 2 3 4
|domain error 

The above (] +/ % #) is even a special parsing rule?

At any rate, the conventions I use help the one who will read my code the most, but I'd still recommend to anyone to avoid long hooks.

----- Original Message -----
From: Raul Miller <rauldmiller at gmail.com>
To: Programming forum <programming at jsoftware.com>
Cc: 
Sent: Monday, May 19, 2014 11:38:24 PM
Subject: Re: [Jprogramming] Understandable J

That's an interesting line of thought.

Note that we can take a fork and ensure that we always use its monadic
definition by prefixing it with the verb ]

Here's a mean example:
mean=: ] +/ % #

   mean 2 3 5 7
4.25
   'see?' mean 2 3 5 7
4.25

Now obviously there isn't a lot of need for this kind of thing - we've gone
for years (decades?) without anyone complaining about its absence. But it's
still kind of neat.

Thanks,

-- 
Raul

On Mon, May 19, 2014 at 11:19 PM, 'Pascal Jasmin' via Programming <
programming at jsoftware.com> wrote:

> Here are some ways to improve readability for me:
>
> lets take,
>
> quicksort=: (($:@(<#[),(=#[),$:@(>#[))({~ ?@#))^:(1<#)
>
> the first step is spacing out the train:
>
> quicksort=: (($:@(<#[) , (=#[) , $:@(>#[)) ({~ ?@#)) ^: (1<#)
>
> the next step is avoiding the hook that takes a while to find due to all
> the parens:
>
> quicksort=: (] ($:@(<#[) , (=#[) , $:@(>#[)) ({~ ?@#)) ^: (1<#)
>
> I find the above superhelpful because the left ] tells me right away that
> it is a fork.
> and then automatically all of the references to [ in the pivot verb are
> actually ones to y argument, and I know that the whole verb is monadic.
>
> optional, but I think still helpful, is to add whitespace to long parens,
> and it doesn't hurt to get rid of right hook:
>
> quicksort=: (] ( $:@(<#[) , (=#[) , $:@(>#[) ) (] {~ ?@#)) ^: (1<#)
>
>
>
>
>
> ----- Original Message -----
> From: Don Kelly <dhky at shaw.ca>
> To: programming at jsoftware.com
> Cc:
> Sent: Monday, May 19, 2014 9:55:33 PM
> Subject: Re: [Jprogramming] Understandable J
>
> Agreed  but both need attention- often the most refined program may be
> the hardest to read.
>
> Don
> On 17/05/2014 9:31 PM, 'Bo Jacoby' via Programming wrote:
> > Improve the program rather than the documentation.
> >
> > Den 4:49 søndag den 18. maj 2014 skrev Don Kelly <dhky at shaw.ca>:
> >
> >
> >>
> >> I find that putting code with lots of explanatory NB.'s  and maybe a
> >> how-to  paragraph as a noun in a script is essential. This also works
> >> for little code snippets than may prove useful in the future (and
> >> sometimes with variations listed).  Examples also help.
> >> This is not only an aid to me, but to others who may use the code. This
> >> came from past APL experience where I would look at something I wrote
> >> and wondered what I did. Starting from scratch is nice but if the hard
> >> work has been done, why do it again
> >> except to improve on  the approach?
> >> There are 2 ways:
> >> 1)intersperse comments within multiline verbs  to help interpretation of
> >> the line
> >> 2)provide a noun such as "howN'
> >> and example of this is the following definition from an Essay on Newton
> >> Raphson
> >> where the following is given
> >>
> >>    N=: 1 : '- u % u d. 1' (which could be given a better name)
> >>
> >> this could be followed by a series of NB.'s in the script indicating
> the usage
> >> NB. (_2+*:)N ^:c]xo solves x^2 =2 using c iterations starting form a
> guess xo
> >> or with more Nb. for more detail.
> >>
> >> Don Kelly
> >>
> >>
> >>
> >>
> >>
> >> On 15/05/2014 11:36 PM, robert therriault wrote:
> >>> Thanks Raul,
> >>>
> >>> I am happy with some of the progress that I am making in my projects
> (and occasionally programming as well), but I like the poetry of J and in
> that way part of the challenge is placing the context through the examples.
> Without that context a poem is just pretty words on a page and a tacit
> expression without examples may not even reveal its valence.
> >>>
> >>> I think that there are opportunities in combining good test driven
> development with the rapid prototyping abilities of J -- but first I am
> playing with J Labs as a medium of expression, education, art etc.
> >>>
> >>> Cheers, bob
> >>>
> >>> ps. I appreciate the support for my work. The fact that I am a
> terrible programmer does not keep me from making terrible programs that
> explore neat ideas. Life's too short to let a lack of talent hold you back
> :-)
> >>>
> >>> On May 15, 2014, at 11:10 PM, Raul Miller <rauldmiller at gmail.com>
> wrote:
> >>>
> >>>> I would not knock "starting from scratch" as a bad thing. Arthur
> Whitney
> >>>> has been known to do that, for example.
> >>>>
> >>>> I think it matters more what you are accomplishing and your ability
> to make
> >>>> that useful for other people.
> >>>>
> >>>> Thanks,
> >>>>
> >>>> --
> >>>> Raul
> >>>>
> >>>>
> >>>> On Fri, May 16, 2014 at 2:07 AM, robert therriault <
> bobtherriault at mac.com>wrote:
> >>>>
> >>>>> I am a terrible programmer, but I have found that including comments
> that
> >>>>> have examples of what the entity should do, are usually enough for
> me to
> >>>>> figure out what is going on.
> >>>>>
> >>>>> Without that ... I usually start from scratch, as that is faster and
> less
> >>>>> frustrating.
> >>>>>
> >>>>> I really am terrible at programming.
> >>>>>
> >>>>> Cheers, bob
> >>>>>
> >>>>>
> >>>>> On May 15, 2014, at 10:52 PM, 'Bo Jacoby' via Programming <
> >>>>> programming at jsoftware.com> wrote:
> >>>>>
> >>>>>> "how does one write understandable J?" One does not write
> understandable
> >>>>> J! One writes as compactly as possible, and if it needs to be
> understood
> >>>>> it's parts are investigated piece by piece. Understandability is not
> a
> >>>>> property of text, but rather a property of relationship between text
> and
> >>>>> reader. / Bo.
> >>>>>> Den 3:51 fredag den 16. maj 2014 skrev Don Guinn <
> donguinn at gmail.com>:
> >>>>>>
> >>>>>> What is easy and obvious depends so much on one's background.
> Several
> >>>>> years
> >>>>>>> ago we tried to teach a woman, at the time in her 80's, how to use
> a
> >>>>>>> Windows computer. Total failure. The real problem was that she
> could
> >>>>> see no
> >>>>>>> use in or reason to use a computer. She had no interest in
> learning it.
> >>>>>>>
> >>>>>>> Anyone who thinks that today's computer technology is intuitive,
> obvious
> >>>>>>> and easy should go to an old folk's home and try to teach them to
> use a
> >>>>>>> smart phone. But for a four-year-old. Piece of cake.
> >>>>>>>
> >>>>>>>
> >>>>>>> On Thu, May 15, 2014 at 6:10 PM, Raul Miller <
> rauldmiller at gmail.com>
> >>>>> wrote:
> >>>>>>>> I am convinced that most code is not understandable to most
> people,
> >>>>>>>> regardless of the language it is written in. When I look at how
> the
> >>>>>>>> computer industry has progressed, I see this more and more. People
> >>>>> write
> >>>>>>>> huge amounts of code, don't document it very well, then other
> people
> >>>>> use
> >>>>>>>> arbitrary bits of it and things sort of just freeze at that point.
> >>>>>>>>
> >>>>>>>> Personally, also, when I read code in any language, I do not feel
> I
> >>>>> really
> >>>>>>>> understand it until I see what it does to representative data.
> >>>>>>>>
> >>>>>>>> So clear descriptions, simple data, and good labels are where I
> would
> >>>>> focus
> >>>>>>>> most of my efforts in making code readable. And I would also
> expect
> >>>>> that
> >>>>>>>> most of my code is going to be unread by most people (and I'll get
> >>>>> dinged
> >>>>>>>> for utterly random stuff by people who do read it).
> >>>>>>>>
> >>>>>>>> I think the point of readability is: you are going to need to be
> able
> >>>>> to
> >>>>>>>> fix it, yourself, when it breaks, so you need to make it readable
> for
> >>>>>>>> yourself. And for that purpose, coming back and trying to read it
> a
> >>>>> month
> >>>>>>>> or so after you've written it can be a good exercise.
> >>>>>>>>
> >>>>>>>> Also, I've found that documenting code is a great way of making
> code
> >>>>>>>> simpler. It's quite often the case that it's easier to change the
> code
> >>>>> to
> >>>>>>>> be easy to document than it is to document some coding quirks that
> >>>>>>>> originally seemed to be a good idea. So if you want readable code,
> >>>>> another
> >>>>>>>> good thing to do is have a technical writer (or at least someone
> >>>>> reasonably
> >>>>>>>> literate) work with the programmer to document it for some
> audience.
> >>>>>>>>
> >>>>>>>> Of course, the most important thing is making sure that it works.
> >>>>>>>>
> >>>>>>>> Thanks,
> >>>>>>>>
> >>>>>>>> --
> >>>>>>>> Raul
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>>
> >>>>>>>> On Thu, May 15, 2014 at 5:23 PM, Kip Murray <
> thekipmurray at gmail.com>
> >>>>>>>> wrote:
> >>>>>>>>
> >>>>>>>>> How does one write understandable J?  I offer my newt adverb
> below
> >>>>> which
> >>>>>>>>> uses spaces to promote understandability.
> >>>>>>>>>
> >>>>>>>>> Another technique might be Linda's "bottom up" style of first
> showing
> >>>>>>>>> pieces then putting the pieces together.  What are your
> techniques?
> >>>>>>>>     Please
> >>>>>>>>> illustrate.
> >>>>>>>>>
> >>>>>>>>> We would like at least to understand our own code when we come
> back to
> >>>>>>>> it!
> >>>>>>>>>       NB. Newton's method
> >>>>>>>>>
> >>>>>>>>>       newt =: 1 : 0
> >>>>>>>>> t =. y
> >>>>>>>>> h =. 1 % 512
> >>>>>>>>> whilst. t ~: s do.
> >>>>>>>>>       s =. t
> >>>>>>>>>       t =. s - +: h * (u s) % (u s + h) - u s - h
> >>>>>>>>>       h =. h % 2
> >>>>>>>>> end.
> >>>>>>>>> t
> >>>>>>>>> )
> >>>>>>>>>       (2 - *:) newt 2   NB. Find root of 2 - *: near 2
> >>>>>>>>> 1.41421
> >>>>>>>>>       (2 - *:) newt _2  NB. Find a root near _2
> >>>>>>>>> _1.41421
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>>
> >>>>>>>>> --
> >>>>>>>>> Sent from Gmail Mobile
> >>>>>>>>>
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>
> >>>>>>>>
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