Re: BBC and DEFINT etc [Was: Using GOTO]

On Sep 9, 5:28 pm, "Judson McClendon" <ju...@[EMAIL PROTECTED]
> wrote:
> One thing that surprised me is the behavior of FOR/NEXT, in always
making
> one iteration, regardless of the initial loop variables. I don't recall
ever using
> a BASIC, or any other language sup****ting FOR, with that behavior.

On the contrary, my recollection is that it was the normal behaviour
at the time BBC BASIC was specified.

> It is very counter intuitive.

I disagree.  I can see no reason to anticipate any particular
behaviour when the initial conditions are meaningless.  A statement
such as FOR i = 3 TO 2 doesn't imply that the loop should be skipped,
it has no logical meaning at all.  'Intuitively' the situation should
never be allowed to arise.

It is clear that a REPEAT..UNTIL (or DO..WHILE) loop performs the test
at the end of the loop, and hence must execute the body of the loop at
least once.  On the other hand a WHILE..ENDWHILE (WHILE..WEND) loop
performs the test at the beginning, and may not execute the body of
the loop at all.  FOR..NEXT is neither one nor the other, and I can't
see why it should preferentially be placed in either category.

> I do see you have added stuff that surely would
> not have been in the original syntax, like C's arithmetic assignment
operators

I didn't add those.  The += and -= (etc.) operators have been in BBC
BASIC since Acorn's version 5, dated around 1985.

> and many Windows API constants

Nope, BBC BASIC has no predefined Windows constants.  Maybe you're
thinking about Liberty Basic, which does.

Richard.
http://www.rtrussell.co.uk/
To reply by email change 'news' to my forename.