Hello,
D has intrigued me for a while, and I thought I would finally
read up on it! I've been reading "Programming in D" by Ali
Çehreli and I've been thinking about how I can use the language
in a side project I'm working on, porting it from java to D. One
of the uncommonly-used features of java that I like is how enums
can be full classes (though I don't like that there's no option
to use enums as e.g. regular ints). This allows several
benefits, such as the ability to use them in switch statements
like regular enums, the full set of objects is known at compile
time, all objects are immutable, it's impossible to accidentally
or purposefully create new objects of that type, etc...
For example (in java), if I wanted to have an enum that describes
all the white keys on a piano keyboard and have members that
describe the number of half-steps to the next white key and to
the previous white key, I can define an enum (the "id" or enum
value is implicitly defined so it doesn't have to be explicitly
written in the definition):
enum WhiteKey
{
A(2,2),
B(2,1),
C(1,2),
D(2,2),
E(2,1),
F(1,2),
G(2,2);
private final int halfStepsToNext;
private final int halfStepsToPrevious;
WhiteKey(int halfStepsPrevious, int halfStepsNext)
{
this.halfStepsToPrevious = halfStepsPrevious;
this.halfStepsToNext = halfStepsNext;
}
}
From what I've read and seen, in D all enums have forced to
integral types. Is it possible to do the above in D and I have
just missed it? I can think of a few ways around it (such as
statically create and define a bunch of WhiteKey structs, ...),
but none are as clean as the above. If this isn't something
supported, is it on a roadmap of wanted features?
Thanks! I'm looking forward to really getting to know the
language.
