[kwlug-disc] Off Topic: APL

[jvj at golden.net]

Wow. I almost forgot that in the 1980s, in a languages course at the UG
I had an APL assignment.
In a small number of lines, 1000 max, I wrote a
small text flat file database utility with all the CRUD functions.
I am
not sure what it would take to do the same in VS C++ or C#. Or even
BASIC.
Thinking back to my APL explorations in the 1970s, at the time, I
did not realize the significance of untyped
variables.
JohnJ

-------------------------
SUBJECT: Re: [kwlug-disc]
Off Topic: APL
DATE: Sat, 20 Jan 2018 15:59:23 -0500
FROM: doug moen

TO: "kb at 2bits.com" , KWLUG discussion 
REPLY-TO: KWLUG discussion 

I
wrote a 3000 line APL program when I was a kid, for a school assignment.
I didn't have the math, or the skill, to write a shorter program. 

What
I didn't like with the language, then, was dynamic scoping, and the old
style of function definition using conditional and unconditional GOTO as
control structures. This was the 1970's. 

The language has improved a
lot. "Direct functions" now let you program in a functional style. 

I
got interested again when I saw this:


https://news.ycombinator.com/item?id=13797797 [1]

It's a 750 line APL
program; an optimising compiler for modern APL that emits GPU code. The
technology staggers me. To reproduce this in C++ would, for me, probably
require 40,000 lines of code. Except that this compiler runs on a GPU, a
feat no one else has accomplished. It's something you can only do in
APL. 

On Saturday, 20 January 2018, Khalid Baheyeldin  wrote:

Wow!


That brings memories.

 In the mid 1980s, I was part of a team to
implement an information system on a mainframe. The mainframe did not
have any data entry method, so the branches would use a PC with a COBOL
application on it to enter the data and store it on 5.25" diskettes. A
driver would collect them and take them to the data centre where they
were uploaded to the mainframe.

 The guy who wrote the COBOL
application for the PC was a seasoned mainframe veteran from Alabama and
was frustrated by the lack of tools on the PC. So he used a PC version
of APL, and its internal full screen editor to edit the COBOL source
code, and then wrote some custom APL to reformat it correctly. That was
amazing.

 It was fascinated by how APL did not use ASCII letters for
directives, but rather mneumonics that looked like playing card symbols.
Also the sheer power of that language/platform. 

On Sat, Jan 20, 2018
at 11:10 AM,  wrote:
 Going OT with the ancient IBM stuff.
I skimmed
past the S/38 and As/400 and know very little about those
machines.
AFAIK The VM capability would let system developers define
target systems somewhat different than the system used for
development.

As a student (circa 1972) I ran Fortran card deck
assignments and personal APL stuff on the 360 aka 360 sickly.
A grad
student created an APL system function that would read a text matrix as
a text file containing a card deck.
When I used this APL function to run
Fortran assignments I noted that my jobs would bump above other jobs
submitted by people who had been standing in line for the card deck
reader.
APL - as an interactive subsystem on the 360 - had a higher
system priority than other jobs, e.g. compiler, assembler, etc.
My lowly
Fortran jobs, submitted through APL, inherited the APL priority.

JohnJ 
        

 

Links:
------
[1]
https://news.ycombinator.com/item?id=13797797
[2]
mailto:kb at 2bits.com
[3] mailto:jvj at golden.net
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