On Tue, 05 Oct 2010 16:32:14 +0400, Bob Cowdery <b...@bobcowdery.plus.com>
wrote:
On 05/10/2010 13:05, Denis Koroskin wrote:
On Tue, 05 Oct 2010 15:53:55 +0400, Denis Koroskin <2kor...@gmail.com>
wrote:
On Tue, 05 Oct 2010 15:40:39 +0400, Bob Cowdery
<b...@bobcowdery.plus.com> wrote:
On 05/10/2010 12:13, Denis Koroskin wrote:
On Tue, 05 Oct 2010 15:08:39 +0400, Bob Cowdery
<b...@bobcowdery.plus.com> wrote:
On 05/10/2010 12:04, Denis Koroskin wrote:
On Tue, 05 Oct 2010 14:57:22 +0400, Bob Cowdery
<b...@bobcowdery.plus.com> wrote:
On 05/10/2010 11:45, Denis Koroskin wrote:
On Tue, 05 Oct 2010 14:23:47 +0400, Bob Cowdery
<b...@bobcowdery.plus.com> wrote:
I can't seem to get any sense out of associative arrays. Even
the
simplest definition won't compile so I must be doing something
daft.
int[string] aa = ["hello":42];
Error: non-constant expression ["hello":42]
What exactly is not constant about this. The example is straight
out the
book. Using D 2.0.
bob
What exactly compiler version are you using (run dmd with no
args)?
Works perfectly fine here (dmd2.049).
It says 2.049. How odd. I've got a fair amount of code and
everything
else compiles fine.
Can you please post complete code snippet that fails to compile?
Here is the code I used to test:
module aa;
import std.stdio;
void main()
{
int[string] aa = ["hello":42];
writeln(aa["hello"]);
}
# dmd -run aa.d
Ah! It's some other code below it that is not giving an error but
causing the error above. So the compiler is getting confused. What
I was
actually trying to do was create an associative array with a
string as a
key and a Tuple as the value. Now
auto aa = [
"some string": (100.0, 6100.0)
]
compiles but is clearly wrong and gives rise to other errors. Does
anyone know the correct way to define this and then access the
tuple.
import std.stdio;
import std.typecons;
void main()
{
auto aa = ["hello": tuple(100.0, 6100.0)];
auto result = aa["hello"];
writeln(result.field[0], " ", result._1); // primary and
alternative way
}
Thanks. I've established that works for me and also that the actual
array I'm using also works in the test program but it won't compile in
the real program. I've commented everything else out of the file and
just left...
import std.typecons;
auto A_RX_FILT = [
"6K0": tuple(100.0, 6100.0),
"2K4": tuple(300.0, 2700.0),
"2K1": tuple(300.0, 2400.0),
"1K0": tuple(300.0, 1300.0),
"500": tuple(500.0, 1000.0),
"250": tuple(600.0, 850.0),
"100": tuple(700.0, 800.0)
];
You are trying to declare global variable and initialize at in
compile time. As far as I know, you can't initialize AA at compile
time atm (this might be implemented in future though).
As such, I'd recommend against using global variables (try moving it
to some class or something). Anyway, you need to initialize it at
some point, either manually:
Tuple!(double,double)[string] A_RX_FILT;
void init()
{
A_RX_FILT = [
"6K0": tuple(100.0, 6100.0),
"2K4": tuple(300.0, 2700.0),
"2K1": tuple(300.0, 2400.0),
"1K0": tuple(300.0, 1300.0),
"500": tuple(500.0, 1000.0),
"250": tuple(600.0, 850.0),
"100": tuple(700.0, 800.0)
];
}
or automatically at thread startup:
static this()
{
init();
}
Hope that helps.
See my other reply for a better solution.
Thanks very much. It compiles now. The reason I thought it was an issue
was because sometime it did compile a global associative array. I need
to do some homework on what 'this' does. It's clearly a powerful concept
and has wider application than class constructors.
"static this" is called a static constructor and can be used for classes
and modules. The code in static constructor is guarantied to be called
before you use that class/module, it usually happens upon thread
initialization.
The other solution is better though:
enum A_RX_FILT = [ // just works
"6K0": tuple(100.0, 6100.0),
"2K4": tuple(300.0, 2700.0),
"2K1": tuple(300.0, 2400.0),
"1K0": tuple(300.0, 1300.0),
"500": tuple(500.0, 1000.0),
"250": tuple(600.0, 850.0),
"100": tuple(700.0, 800.0)
];
