On Monday, 4 June 2018 at 03:18:05 UTC, Jonathan M Davis wrote:
I think that part of your problem here comes from the fact that
you think of enum or static are "CTFE keywords." That's not
what they are at all. Yes, they can trigger CTFE, but they're
not the only way.
...
Thank you very much for the extensive explanation, I really
appreciate it. I'm slowly getting the point here, also by reading
the relevant parts of the book you linked.
I was aware of the meaning of the static keyword (coming from
other languages where it has similar meaning), but your re-cap
was great anyway since I now have a clear view of how exactly
works in D with the various features of the language.
So, while static _seems_ somewhat inconsistent at first, the
way it's used is pretty consistent overall. The main
inconsistency is the places where static is essentially
implicit rather than explicit (such as module-level variables
or structs nested in other structs or classes).
I'm not getting this however. I mean, sure, it's totally
consistent if you consider the cases you described, but what I
meant is that in a piece of code like
static if (a == 3)
{
// stuff...
}
static else if (a == 2)
{
// other stuff...
}
else
{
// etc...
}
the "static" keyword has a different meaning, in this case it
means that the if gets evaluated at compile time. This is the
kind of inconsistency I was talking about.
Of course "static if" doesn't sound bad at all, it somehow
conveys the idea of what it actually does. My confusion was
regarding the fact that "static" is also used for other things
(the ones you described) and then I would also expect that, to
define a compile-time value, I would use the same keyword again,
like
static myCompileTimeValue = 5 * 2;
instead of
enum myCompileTimeValue = 5 * 2;
of course this wouldn't be possible with the keyword "static",
since `static val = 4;` would have a totally different meaning in
the language, and that's why "enum" is used I guess. But then why
not `enum if (...) { ... }`? Again, forget about the keywords
themselves, I'm just talking about using the same one which is
different from keywords that also do other different (or
completely different, or slightly different, but still different)
things. I get that "enum" has somewhat of a sense, when doing
`enum val = 4;`, after reading the related book chapter, but
yeah... that's not the problem, as I hope you now understood what
I mean.
If you haven't yet, I'd suggest reading
http://ddili.org/ders/d.en/index.html
Even if you understand most of the content already, it will
probably help fill in some of the holes you have in your
understanding, and depending on how much you've done with D, it
may contain quite a bit of new content that will help you out.
- Jonathan M Davis
Again, thank you very much for the time you took to answer with
that amount of quality information, I really appreciate it. And I
also appreciate the suggestion about the book, which I'll read as
soon as I can. Maybe I'm missing somewhat of a broader view of
the language that, once acquired, will make me understand the
real meanings/reasons behind those keywords.
This argument I started was kind of a first-impression as a
newcomer to the language, with the hope of getting to better
understand it. Also I thought it's beneficial for the community
to have feedback from new users.
Thank you very much again,
Giacomo
