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From: Atle <trollet@skynet.be>
Newsgroups: comp.lang.beta
Subject: Turbo Beta?
Date: Tue, 20 Jun 2000 13:14:14 -0100
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Hello, again!

Now I have an entirely different question:
Do any of you remember UCSD Pascal?
Or Turbo Pascal for CPM?
They even continued with them Turbo C for DOS, then Windows - until it got too big and 'tungrodd'(?)
Have any of you written a simple programming environment like that?

-----------------------------
Can any of you give me an idea about how to program something like that an at the same time gain some insight in the concept of
coroutines and generators?
-----------------------------


If you want an idea from me on how to play with generators yourselves, I have a good one:

Databases.

A SELECT could be implemented as a generator (of course, it wouldn't be an SQL SELCT anymore, so it would need another name).

In Icon, the keyword EVERY returns all the values, as in

EVERY s := ['atle', 'Beta', 'Concurrency', 'Delta', 'every', 'fork', 'generator'] DO
	write (s)

So each element of the list in [] will be assigned to s in turn and written.

To program a generator, you have to call

	SUSPEND s

with the value of s (in the list that is the 'next' element).

So, a generator in Icon is one that is used like this to print all its values

every elm := mygenerator() do write elm

And the way in Turbo C for DOS was like the famous (?)

	findfirst(filespec, &ffblk);
	while(findnext(&ffblk))
		printf("%s\n", ffblk.ff_name); /* Or something like that (long time ago)*/

If struct ffblk was 'static', it would remember its state between calls to whatever function called findnext(). Like the FILE is
poor man's object, well, this would be
Yes, folks, a generator programmed in Turbo C :-)

It seems to be that these things would have gotten the most elegant implementation thinkable in Beta.

I will be looking at the SQL interface with a lot of interest soon ... i hope there is something built on top of that. It would be a
piece of cake for someone who knew Beta well to build a RAS - Relational Algebra System on top of SQL - I think. At least I know it
would be fun.

But I need to learn more, and more ...

Atle