Package's private parts and protected types
in [ADA]
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From: Stephen Leake on 13 Feb 2010 03:00 Robert A Duff <bobduff(a)shell01.TheWorld.com> writes: > Stephen Leake <stephen_leake(a)stephe-leake.org> writes: > >> Robert A Duff <bobduff(a)shell01.TheWorld.com> writes: >> >>> Adam Beneschan <adam(a)irvine.com> writes: >>> >>>>...And that >>>> issue exists with GNAT also---you delete some files from your >>>> directory with a wildcard, somehow foo.adb accidentally gets deleted >>>> along with them, and the compiler still thinks your program is OK. >>> >>> Seems unlikely. >> >> Which means it will be very hard/confusing to debug when it does >> happen, since you will not be familiar with the problem. So it is >> important for the tool to handle the unlikely situations nicely. > > I suppose... > >>> Here's a similar issue: One reasonable design pattern is to have >>> a body that contains a type extension, which registers itself >>> into some global data structure. All calls to this thing >>> are indirect (via the parent's 'Class). Nobody needs visibility >>> on this thing, so its spec is completely empty, except for >>> the obligatory pragma Elaborate_Body. Unfortunately, if you >>> forget to 'with' it, it will be silently ignored. >> >> And if you do 'with' it, GNAT will complain that it's unnecessary, so >> you have to put a pragma Warnings (off) on it. QtAda does this for >> some stuff; it's annoying. > > But that's a hugely useful warning. Without it, you end up with > useless 'with's accumulating in your code. An occassional > pragma Warnings is well worth the trouble, IMHO. Yes, I agree. Actually, most of the annoyance is that Emacs Ada mode doesn't understand about the pragma, so when it automatically adds a new with clause, and alphabetically sorts the set of with clauses, it messes things up. So I need to teach Emacs Ada mode how to cope with that better. -- -- Stephe |