Re: Proposed change to BC iterator parameters

[Robert A Duff <bobduff@shell01.TheWorld.com>]

"amado.alves" <amado.alves@netcabo.pt> writes:

> <<...
>   Avoid global data
>   All inputs and outputs of a procedure should appear in their parameter
> lists
> 
> Following these simple guidelines usually makes code a lot easier to follow.>>
> In the big, yes, but not in the small, namely in loops, ifs, and... visits.

That's a good point.  The reason this thing is a generic, forcing the
body of the loop to be in a separate procedure, is that Ada has such
weak support for iterators.  If a procedure is naturally a procedure,
then it might make sense to say that it shouldn't be messing around with
global data.  But in this case, it's just the body of a loop, so *of
course* it touches the data local to the procedure containing the loop.
The fact that those variables are global to the loop-body procedure is
accidental.

- Bob