Re: APL & Programming Concepts

"AAsk" <AA2e72E@[EMAIL PROTECTED]
> wrote in message
news:b4bae487-0159-44fd-9abd-1346553431a0@[EMAIL PROTECTED]
> "I thought datatypes where implicit in APL." Indeed they are, much as
> with JavaScript, VBScript, etc.
> APL does have another twist, that you do not need to 'declare' a
> variable.
[...]
> In APL it is simply
>
> name<-'APL'

I know ...

> If you are using APL to teach programming concepts (of which data
> typing is a part), how would you impart the concept from an APL
> environment/workspace?


say, we need to produce figures for a yearly report; we round to
millions; the sums should fit.
then in K, e.g you'd write

f:{x*(_ y)+(<>d)<-0.5+/d:(y:y%x)!1}

or (one to one) in APL
r<-x{times}({negate}y)+({upgrade}{downgrade}d){lessthen}{minus}0.5+/d<-(y<-y{divide}x){iota}1}

try this in e.g. in Fortran.
(already the upgrade-downgrade is impossible, because you'll need the
indices from the downgrade).

Please, tell us, why should we write (and still learn)

BEGIN
FOR I = 1 TO 100
.... some operation, in this case addition
NEXT I
END
oslt

rather then +/n ?

Three examples from other "industries":

1. why was my wife  when at graphic art school learning how to put texts
on a composer-stick, while everybody could just grab his keyboard and
produce any typeface he wants?

2. in composing music they're teaching in schools that fifth's (and
octaves) parallels are forbidden; many composers (even the most famous
like J.S.B.) always knew to find a work around; and Schoenberg (in 1907
finally) therefore asked: why? do they sound bad? why? So, why is this
still taught at conservatories?

3. Do you need to know how many valves your car engine has and how they
are synchronized to drive your car? Yes, for an expert car mechanic, but
for driving from London to High Wycomb?

Why is all that looping around still being taught at schools?

I know the answer: inertia and mass - still after 40 years of APL (and J
and K)
jk