On Thu, 5 Apr 2018, Ondrej Pokorny wrote:
On 05.04.2018 0:34, Michael Van Canneyt wrote:
What, because you do not agree ?
No, because I didn't get any arguments against.
You did, you just don't consider them valid.
There are 2 narratives, and you choose to ignore the 2nd one.
Now, it is also correct that the compiler developers are aware that
many people rely on this implementation detail.
Since when is documented behavior considered as "implementation detail"?
This is not an implementation detail. It is in official documentation.
You and I know very well that this is an implementation detail, needed
for internal bookkeeping of the compiler. That the delphi manual states
otherwise, I have always considered a grave error on their part:
It contradicts one of the core tenets of pascal - see below.
If the compiler devs wanted, they could initialize every string with the
'<undefined string>' constant, every interface with a reference to a constant
IUnknown interface, and that would be equally correct as the current
behaviour from a compiler perspective.
(in fact, it would be an interesting test to do so. See how much code breaks)
Unfortunately, a value is needed for internal bookkeeping of the compiler.
Which value that is, is entirely irrelevant from a compiler perspective.
0 is simply convenient, no more, no less.
Pascal states: do not assume that variables are initialized.
That is the "rule".
From this rule, it follows that every variable must be explicitly initialized
by the
programmer at least once before using it, to have correct and predictable
behaviour: Be it with an assignment or an 'var a: type = someonstant;'.
So, if the compiler sees code that uses a variable which is not explicitly
initialized, it warns.
Simple and consequent.
That the warning has been split in 2 warnings is for your convenience.
I suggest you put it to good use.
Michael.
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