In the SiliconValley-ForthInterestGroup Zoom Sat.Sep,20200926  Bill Ragsdale , one of the elders of the Forth community , gave an update on recent  Forth related activity on Facebook & Zoom .
And most significantly , moderated a challenge of 4 questions to be constructed in Forth . About a half dozen of us participated . I , of course , demonstrated  CoSy ` APL style solutions , but others presented their , sometimes brilliant solutions in traditional Forth . Overall , they give a good picture of the nature of Forth programming  compared to other  ` C based languages .

The major thing to note about the CoSy solutions versus the traditional Forth solutions is that while CoSy at each step creates or transforms lists ( objects ) in a very functional style like other higher level competitive languages , the Forth examples simply print the bits of results as they loop along .

Take a look at the video , and then play from the beginning to see Bill Ragsdale's comments on recent Forth events and Dr Ting's latest comments on COVID-19 genomes & mutations .

-------- Forwarded Message --------

Subject:	[svfig] SV FIG, Sept 26 Programming Challenge
Date:	Tue, 22 Sep 2020 11:50:15 -0700
From:	Bill Ragsdale <billragsdale@earthlink.net>
Reply-To:	bill@billragsdale.cc, Silicon Valley Forth Interest Group <svfig@zork.net>
To:	Forth Interest Group <svfig@zork.net>

Dear Forther,

You are invited to participate in a Forth Programming Challenge on Saturday, Sept. 26, 2020 as part of the monthly Silicon Valley Forth Interest Group meeting. This is not a contest, just show and tell. You are welcome to program solution(s) or just comment on any of the challenges.

When: Zoom meeting Sept. 26, 2020,  1:00 PM Pacific Daylight Time, 20:00 UTC. Meeting ID: 885 5518 3911, Passcode: FIG.

The Challenges:

1)     Print the alphabet  “AbCdEfGh . . . z” in alternating case using three methods.

2)     Print a table headed by 240 to 249 across with 170 to 179 down. At each intersection show the Greatest Common Divisor.

3)     Print the five largest prime numbers less than 10,000.

4)     Using numbers, terminal characters or graphics plot x-squared from 1 to 10.

Questions or suggestions:   Bill Ragsdale, bill@billragsdale.cc

-------- Forwarded Message --------

Subject:	Re: [svfig] Challenge // Friday Warm-up // Re: SV FIG, Sept 26 Programming Challenge
Date:	Wed, 23 Sep 2020 22:02:25 -0600
From:	Bob Armstrong <bob@cosy.com>
Reply-To:	Silicon Valley Forth Interest Group <svfig@zork.net>
To:	Silicon Valley Forth Interest Group <svfig@zork.net>, Kevin Appert <forther@comcast.net>
CC:	Bill Ragsdale <bill@billragsdale.cc>

I did Greatest Common Denominator problem back around the first of the month . And in fact included it in my http://cosy.com/y20/Wed.Sep,20200902.html blog post . Most consequentially ( and rather unexpectedly ) it shows how trivial it is to make any raw Forth verb taking a fixed number of parameters and producing a single result into a CoSy list function inheriting all that list vocabulary .

Back when I was learning APL on the CDC6600 , I spent a lot of time seeing if I could optimize Eratosthenes sieve to match the best Fortran . Couldn't , but came respectably close . APL is about half good & half bad at it . Forth should win .

This ( Wed ) morning some post prompted me to look at the others .  I'm not going to do 3 ways of mixing the letters , but I did do this for the alphabet :

   i( 65 97 )i 26 _iota { +i i>c } 'R ,/
AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz

and this for the graph :

   "bl 10 _iota dup *i ' take 'R ` o ' cL 'L
(
 o
  o
     o
          o
                 o
                          o
                                     o
                                                  o
                                                                 o
                                                                                  o
 )

Of course these answers are returned as lists , not just printed out .

I'm not trying to say the APL level is ` better than the Forth ; it's that they address different domains .
And that's why an APL , evolved thru K , as an open vocabulary in Forth , has capabilities no previous language can match . And I'm not going to shy away from challenges . They are always useful tests .

Bob A
--
See Wed.Sep,20200902 for answer to Greatest Common Divisor problem
--

Note : I , like Brad Nelson , failed reading the alternating upper-lower case alphabet problem correctly . Here's the simple solution I wrote during the meeting as soon as I became aware of our error :