Re: APL - Alive and Well!

Here are a few comments on Mortens excellent points:

On May 11, 9:14=A0am, Morten Kromberg <mk...@[EMAIL PROTECTED]
> wrote:
> It DOES seem to be true that:

>
> 4. It is almost impossible to interest Computer Science departments in
> APL.
>
VERY TRUE, I tried for years.
However, the basic strengths of the Array oriented languages for
analytical computing is being
recognized by non-academic practitioners.

>
>
> So yes: There ARE many large APL (based) businesses which have died -
> but the APL family of languages will not die unless they are one day
> replaced by something MORE CAPABLE in the areas where APL is strong.
> This is quite simply because it provides unique value in a number of
> situations. The market that these situations represent is rapidly
> growing, and very poorly served by other technologies, so there is
> significant room for growth for APL, J, K and other new dynamic and
> array-oriented software development methodologies. The mainstream
> software industry is only just starting to ****ft its focus from
> administrative systems to analytical software, and we have a 40-year
> head start. If you look at trends in modern programming languages,
> they are heading in OUR direction: Dynamic languages, Type inference
> in languages like C#, growing use of "Reflection" (inspecting types
> and doing different things depending on what was passed to you), all
> of these are signs that mainstream technology is waking up to the fact
> that if you want to write code quickly, and especially if it needs to
> do anything analytical, you need the kind of flexibility that APL
> already has.
>
> This would be a VERY BAD TIME to start moving the language towards
> where everyone else is now!
>
BUT, it is a very good time for thinking about how to take the best of
the Array oriented
language ideas and incor****ate them into toolkits for doing agile
computing.
Morten's remarks on this are on target.

I have spent a lot of time thinking about the "best" combination of
programming language
ideas and array oriented programming from both a theoretical and
practical viewpoint.
I do not see any magic combination that will sweep the programming
world emerging soon.

>
> c. APL is pretty useless in a Computer Science department. It is not
> the goal of these institutions to teach the art of extracting
> specifications or the construction of working software so APL has
> little to offer them (OK, I admit have a chip on my shoulder: I
> dropped out of CS pretty early on after discovering that only 15-20%
> of the marks were given for arriving at a working solution).
>

The software engineering side of computer science departments rarely
teach or do research on the sort of rapid prototyping and
evolutionary
application design that APLers have experience with.
My work on Q'Nial was an effort to get CS people interested in the
class
of language that sup****ts such activities. I failed to gain very many
converts.

The key aspect that APL, J, K, and Nial have is the ability to achieve
a complex
result as a sequence of functional transformations on data structures.
Programming becomes the task of placing data into initial structures
and transforming
them by selecting the appropriate functions in the correct order.
This is not as simple as it sounds because:
- we may need more than one data structure
- we may need to retain (or simply name) intermediate results
- we may have to add functions not provided in the predefined set
- we may need to make choices between functions to apply
- we may need to repeat sequences of function applications

All of the array languages provide a way to meet the above needs.

The hard part is to teach students how to solve problems with this
functional paradigm.
It requires the mental ability to hold the data structure in one's
mind and to imagine how
particular functions will transform it. Some students are better at
this than others.

My guess is that most avid array language programmers do this quite
easily and find it
strange that others have difficulty doing it.

The efforts by Dyalog to improve educational materials and examples of
solving problems
using APL are im****tant for achieving the goal of making the array
style of programming
more widespread.

I have been reading comp.lang.apl for the past year or so (since I
announced the Q'Nial open
source project). I think it is im****tant to use it as a place to share
ideas about how to use
APL and J and news on related products.

Mike Jenkins