Thanks for the tips.
I will attempt to emphasize the practical values of 1) being able to hold
an entire solution in one's head
at once, and 2) time-to-completion as a good metric of efficiency, not
"how quickly code runs".
For the parens example, I'm thinking of showing it something like this:
phrase=. '0{11{22{333}222}1}0'
+/\ 1 _1 0 {~ '{}' i. phrase
Then backing up to explain successive sub-expressions in order of
evaluation. I may further elaborate by assigning the verb to a name and
generalizing this to take a left argument of the paren pair to use. This
will allow me to introduce the tacit/explicit distinction as well.
I think my basic problem is to avoid trying to cover too much, so I'm now
thinking of showing a few other variants of scan, then maybe "cut" or the
"power" conjunction.
On Fri, Jan 17, 2014 at 11:24 AM, Roger Hui <[email protected]>wrote:
> Suggestion: Make more of a distinction between the data and the code.
> Thus:
>
> x=: '@{ foo; if (abc) { if (q) { m; } } }'
>
> +/\ 1 _1 0 {~ '{}' i. x
>
>
>
>
>
> On Fri, Jan 17, 2014 at 7:50 AM, Joe Bogner <[email protected]> wrote:
>
> > If it's helpful for the presentation, I wrote up how the parentheses
> > nesting idiom looks in a few other languages:
> >
> > There are two relevant concepts - the array thinking and the
> implementation
> >
> > J
> > +/\(1 _1 0){~'{}' i. '@{ foo; if (abc) { if (q) { m; } } }'
> > 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 2 2 1 1 0
> >
> > Javascript
> > var runsum=0;'@{ foo; if (abc) { if (q) { m; } }
> > }'.split('').map(function(x) { var opp={'{':1,'}':-1}; return
> > opp[x]||0; }).map(function(x) { runsum = x+runsum; return runsum; })
> > 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2,
> > 2, 2, 2, 3, 3, 3, 3, 3, 2, 2, 1, 1, 0
> >
> > PicoLisp
> > (reverse (mapcon '((X) (list (apply + X))) (reverse (mapcar '((X)
> > (cond ((= X "{") 1) ((= X "}") -1) (T 0))) (chop "@{ foo; if (abc) {
> > if (q) { m; } } }")) ) ))
> > (0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 3 3 3 3 3 2 2 1 1 0)
> >
> >
> >
> http://csilo.com/!article?2014/01/15/J-vs-Javascript-vs-PicoLisp-short-comparison
> >
> > On Fri, Jan 17, 2014 at 10:41 AM, Devon McCormick <[email protected]>
> > wrote:
> > > I'll be talking on J to a meetup here in New York this coming Tuesday -
> > > http://www.meetup.com/7-Languages-in-7-Months-NYC/ - so I've been
> > watching
> > > the "fork examples" discussion w/some interest.
> > >
> > > I did a dry run of my talk at NYCJUG this past Tuesday and, at that
> > time, I
> > > was looking to build up to a final, mind-blowing example like the
> > > Newton-Raphson iterator, but now am thinking that that's too "tricky"
> and
> > > what I'd really like to do is go into detail on some simpler examples.
> > Joe
> > > Bogner's interest in the parenthesis-nesting idiom reminded me of how
> > > innovative the array approach still is, so I'm definitely using that
> one.
> > >
> > > David Lambert, who was at the NYCJUG meeting has also given me a couple
> > of
> > > good ideas since then but I'm interested in anyone else's favorite J
> > idiom
> > > - "Jems" as Dan would have it - that illustrate the usefulness of array
> > > thinking.
> > >
> > > Thanks,
> > >
> > > Devon
> > > --
> > > Devon McCormick, CFA
> > > ----------------------------------------------------------------------
> > > 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
>
--
Devon McCormick, CFA
----------------------------------------------------------------------
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