Dear Thinkers,
Already in Chapel, there is an attribute of any variable or expression
called '.type', such that, given definitions like
var vr : real(64);
var vi : int(32);
then
vr.type
or even
(vi * 55.5).type
returns a concept/value/thing which is
real
and so on. This allows for such usage as
var t : vr.type;
which defines 't' as being a real(64) variable.
Is there an equivalent to C's sizeof for types and expressions?
For example, and remembering that '.size' has already been commandeered
for use with range and arrays to return the number of components or items
in either a range or an array, I want to do something like
// find out what the size of a variable is
if vr.bits == 64 then
{
writeln("64 bit quantity");
}
else
{
writeln("not 64-bits at all");
}
or more precisely (yes Michael, took your advice)
var r : real(64);
var i : int(r.bits);
var rsize : int(32) = r.bits >> 3; // divide by 8
....
memcpy(i, r, rsize);
where memcpy is defined as a C function.
I apologize if bits is meaningful in other contents. And it also begs the
other question of whether one's brain, when in 'mode=Chapel', should think
in terms of bits or bytes.
Personally I prefer sizeof/typeof/bitsof but I can run with whatever.
Now this time as I keep getting reminded, I did go fishing in
README.*
in
doc/{release,}/technotes
and could not find anything relevant. It might be there but I could not
find it. If it is, then I need to go and start shopping for glasses. I
also could not find this in the primary documentation.
Also, as an aside, what other attributes of types beside '.type' are
predefined.
Regards - Damian
P.S. And while we are at it, on a philsophical point,
Is something as fundamental to a variable as say the absolute value of a
number 'x', floating or integral, or even say its sign, given by
a) attribute of the number, i.e. given by
x.abs
b) method applied to that number, i.e. given by
x.abs()
c) some function call
abs(x : T) : T
Not looking for a religious war here. Just some feedback.
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