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October 05, 2010
Re: Associative arrays give compile error
On Tue, 05 Oct 2010 15:50:44 +0400, Bob Cowdery <bob@bobcowdery.plus.com>  
wrote:

>  On 05/10/2010 12:40, Bob Cowdery wrote:
>>  On 05/10/2010 12:13, Denis Koroskin wrote:
>>> On Tue, 05 Oct 2010 15:08:39 +0400, Bob Cowdery
>>> <bob@bobcowdery.plus.com> wrote:
>>>
>>>>  On 05/10/2010 12:04, Denis Koroskin wrote:
>>>>> On Tue, 05 Oct 2010 14:57:22 +0400, Bob Cowdery
>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>
>>>>>>  On 05/10/2010 11:45, Denis Koroskin wrote:
>>>>>>> On Tue, 05 Oct 2010 14:23:47 +0400, Bob Cowdery
>>>>>>> <bob@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)
>> ];
>>
>> I get an error on every line:
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(100,6100) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(300,2700) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(300,2400) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(300,1300) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(500,1000) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(600,850) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(700,800) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(100,6100) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(300,2700) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(300,2400) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(300,1300) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(500,1000) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(600,850) at
>> compile time|
>> Definitions\dspDefs.d|51|Error: cannot evaluate tuple(700,800) at
>> compile time|
>> ||=== Build finished: 14 errors, 0 warnings ===|
>>
>> This is a bit worrying now. I moved the array into the file that uses it
>> but I still get the same errors. Any ideas?
>>
>>
> Oh dear, this is getting worse and worse. I've still got problems with a
> simple definition. If I take out the one with the tuple and leave in
> this one:
>
> enum E_MODE
> {
>   LSB,                //  0
>   USB,                //  1
>   DSB,                //  2
>   CWL,                //  3
>   CWU,                //  4
>   FMN,                //  5
>   AM,                //  6
>   DIGU,                //  7
>   SPEC,                //  8
>   DIGL,                //  9
>   SAM,                // 10
>   DRM                // 11
> }
> // Associative array for translation
> auto A_MODE = [
>     "LSB": E_MODE.LSB,
>     "USB": E_MODE.USB,
>     "DSB": E_MODE.DSB,
>     "CWL": E_MODE.CWL,
>     "CWU": E_MODE.CWU,
>     "FMN": E_MODE.FMN,
>     "AM": E_MODE.AM,
>     "DIGU": E_MODE.DIGU,
>     "SPEC": E_MODE.SPEC,
>     "DIGL": E_MODE.DIGL,
>     "SAM": E_MODE.SAM,
>     "DRM": E_MODE.DRM
> ];
>
> I get:
> Definitions\dspDefs.d|25|Error: non-constant expression
> ["LSB":cast(E_MODE)0,"USB":cast(E_MODE)1,"DSB":cast(E_MODE)2,"CWL":cast(E_MODE)3,"CWU":cast(E_MODE)4,"FMN":cast(E_MODE)5,"AM":cast(E_MODE)6,"DIGU":cast(E_MODE)7,"SPEC":cast(E_MODE)8,"DIGL":cast(E_MODE)9,"SAM":cast(E_MODE)10,"DRM":cast(E_MODE)11]|
> ||=== Build finished: 1 errors, 0 warnings ===|
>
> Something is seriously broken here.
>
>

Try using enum A_MODE instead of auto A_MODE, it should help. Sorry for  
confusion.
October 05, 2010
Re: Associative arrays give compile error
On Tue, 05 Oct 2010 15:53:55 +0400, Denis Koroskin <2korden@gmail.com>  
wrote:

> On Tue, 05 Oct 2010 15:40:39 +0400, Bob Cowdery  
> <bob@bobcowdery.plus.com> wrote:
>
>>  On 05/10/2010 12:13, Denis Koroskin wrote:
>>> On Tue, 05 Oct 2010 15:08:39 +0400, Bob Cowdery
>>> <bob@bobcowdery.plus.com> wrote:
>>>
>>>>  On 05/10/2010 12:04, Denis Koroskin wrote:
>>>>> On Tue, 05 Oct 2010 14:57:22 +0400, Bob Cowdery
>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>
>>>>>>  On 05/10/2010 11:45, Denis Koroskin wrote:
>>>>>>> On Tue, 05 Oct 2010 14:23:47 +0400, Bob Cowdery
>>>>>>> <bob@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.
October 05, 2010
Re: Associative arrays give compile error
On 05/10/2010 13:05, Denis Koroskin wrote:
> On Tue, 05 Oct 2010 15:53:55 +0400, Denis Koroskin <2korden@gmail.com>
> wrote:
>
>> On Tue, 05 Oct 2010 15:40:39 +0400, Bob Cowdery
>> <bob@bobcowdery.plus.com> wrote:
>>
>>>  On 05/10/2010 12:13, Denis Koroskin wrote:
>>>> On Tue, 05 Oct 2010 15:08:39 +0400, Bob Cowdery
>>>> <bob@bobcowdery.plus.com> wrote:
>>>>
>>>>>  On 05/10/2010 12:04, Denis Koroskin wrote:
>>>>>> On Tue, 05 Oct 2010 14:57:22 +0400, Bob Cowdery
>>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>>
>>>>>>>  On 05/10/2010 11:45, Denis Koroskin wrote:
>>>>>>>> On Tue, 05 Oct 2010 14:23:47 +0400, Bob Cowdery
>>>>>>>> <bob@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.
October 05, 2010
Re: Associative arrays give compile error
On Tue, 05 Oct 2010 16:32:14 +0400, Bob Cowdery <bob@bobcowdery.plus.com>  
wrote:

>  On 05/10/2010 13:05, Denis Koroskin wrote:
>> On Tue, 05 Oct 2010 15:53:55 +0400, Denis Koroskin <2korden@gmail.com>
>> wrote:
>>
>>> On Tue, 05 Oct 2010 15:40:39 +0400, Bob Cowdery
>>> <bob@bobcowdery.plus.com> wrote:
>>>
>>>>  On 05/10/2010 12:13, Denis Koroskin wrote:
>>>>> On Tue, 05 Oct 2010 15:08:39 +0400, Bob Cowdery
>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>
>>>>>>  On 05/10/2010 12:04, Denis Koroskin wrote:
>>>>>>> On Tue, 05 Oct 2010 14:57:22 +0400, Bob Cowdery
>>>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>>>
>>>>>>>>  On 05/10/2010 11:45, Denis Koroskin wrote:
>>>>>>>>> On Tue, 05 Oct 2010 14:23:47 +0400, Bob Cowdery
>>>>>>>>> <bob@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)
];
October 05, 2010
Re: Associative arrays give compile error
On 05/10/2010 13:45, Denis Koroskin wrote:
> On Tue, 05 Oct 2010 16:32:14 +0400, Bob Cowdery
> <bob@bobcowdery.plus.com> wrote:
>
>>  On 05/10/2010 13:05, Denis Koroskin wrote:
>>> On Tue, 05 Oct 2010 15:53:55 +0400, Denis Koroskin <2korden@gmail.com>
>>> wrote:
>>>
>>>> On Tue, 05 Oct 2010 15:40:39 +0400, Bob Cowdery
>>>> <bob@bobcowdery.plus.com> wrote:
>>>>
>>>>>  On 05/10/2010 12:13, Denis Koroskin wrote:
>>>>>> On Tue, 05 Oct 2010 15:08:39 +0400, Bob Cowdery
>>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>>
>>>>>>>  On 05/10/2010 12:04, Denis Koroskin wrote:
>>>>>>>> On Tue, 05 Oct 2010 14:57:22 +0400, Bob Cowdery
>>>>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>>>>
>>>>>>>>>  On 05/10/2010 11:45, Denis Koroskin wrote:
>>>>>>>>>> On Tue, 05 Oct 2010 14:23:47 +0400, Bob Cowdery
>>>>>>>>>> <bob@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)
> ];
I'm not totally understanding that. Why can enum compute that at compile
time and the thing which it is, an associative array cannot. Is it to do
with where these things live.
October 05, 2010
Re: Associative arrays give compile error
On Tue, 05 Oct 2010 17:00:13 +0400, Bob Cowdery <bob@bobcowdery.plus.com>  
wrote:

>  On 05/10/2010 13:45, Denis Koroskin wrote:
>> On Tue, 05 Oct 2010 16:32:14 +0400, Bob Cowdery
>> <bob@bobcowdery.plus.com> wrote:
>>
>>>  On 05/10/2010 13:05, Denis Koroskin wrote:
>>>> On Tue, 05 Oct 2010 15:53:55 +0400, Denis Koroskin <2korden@gmail.com>
>>>> wrote:
>>>>
>>>>> On Tue, 05 Oct 2010 15:40:39 +0400, Bob Cowdery
>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>
>>>>>>  On 05/10/2010 12:13, Denis Koroskin wrote:
>>>>>>> On Tue, 05 Oct 2010 15:08:39 +0400, Bob Cowdery
>>>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>>>
>>>>>>>>  On 05/10/2010 12:04, Denis Koroskin wrote:
>>>>>>>>> On Tue, 05 Oct 2010 14:57:22 +0400, Bob Cowdery
>>>>>>>>> <bob@bobcowdery.plus.com> wrote:
>>>>>>>>>
>>>>>>>>>>  On 05/10/2010 11:45, Denis Koroskin wrote:
>>>>>>>>>>> On Tue, 05 Oct 2010 14:23:47 +0400, Bob Cowdery
>>>>>>>>>>> <bob@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)
>> ];
> I'm not totally understanding that. Why can enum compute that at compile
> time and the thing which it is, an associative array cannot. Is it to do
> with where these things live.

Let's say it's a limitation of dmd compiler. I'll submit a bug report.
October 05, 2010
Re: Associative arrays give compile error
On Tue, 05 Oct 2010 09:00:13 -0400, Bob Cowdery <bob@bobcowdery.plus.com>  
wrote:

>  On 05/10/2010 13:45, Denis Koroskin wrote:

>> "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)
>> ];
> I'm not totally understanding that. Why can enum compute that at compile
> time and the thing which it is, an associative array cannot. Is it to do
> with where these things live.

I'd be very wary of this solution.  Recently, enum has been shown to  
construct itself on every use.

So what I think is happening is every time you use A_RX_FILT, it's  
building a brand new AA (you can verify this by looking at the  
disassembly).

I'd recommend the static this solution in order to ensure you are not  
accidentally killing performance by just using that AA.

A while back, Don suggested that all literals should be considered  
immutable.  I agree with him, but Walter still doesn't.  If all literals  
are immutable, then they could be truly constructed at compile-time.

-Steve
October 05, 2010
Re: Associative arrays give compile error
On 05/10/2010 15:14, Steven Schveighoffer wrote:
> On Tue, 05 Oct 2010 09:00:13 -0400, Bob Cowdery
> <bob@bobcowdery.plus.com> wrote:
>
>>  On 05/10/2010 13:45, Denis Koroskin wrote:
>
>>> "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)
>>> ];
>> I'm not totally understanding that. Why can enum compute that at compile
>> time and the thing which it is, an associative array cannot. Is it to do
>> with where these things live.
>
> I'd be very wary of this solution.  Recently, enum has been shown to
> construct itself on every use.
>
> So what I think is happening is every time you use A_RX_FILT, it's
> building a brand new AA (you can verify this by looking at the
> disassembly).
>
> I'd recommend the static this solution in order to ensure you are not
> accidentally killing performance by just using that AA.
>
> A while back, Don suggested that all literals should be considered
> immutable.  I agree with him, but Walter still doesn't.  If all
> literals are immutable, then they could be truly constructed at
> compile-time.
>
> -Steve
I'm happy with the static this solution so will leave well alone. I
generally keep mutable and immutable data structures apart so I tend to
agree that literals should be immutable although of course I'm not aware
of the pros and cons.

bob
October 05, 2010
Re: Associative arrays give compile error
Denis Koroskin:

> 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
> }

Now Tuples accept the natural syntax too:
writeln(result[0], " ", result[1]);

----------------------------------------

Bob Cowdery:

> enum E_MODE
> {
>   LSB,                //  0
>   USB,                //  1
>   DSB,                //  2
>   CWL,                //  3
>   CWU,                //  4
>   FMN,                //  5
>   AM,                //  6
>   DIGU,                //  7
>   SPEC,                //  8
>   DIGL,                //  9
>   SAM,                // 10
>   DRM                // 11
> }
> // Associative array for translation
> auto A_MODE = [
>     "LSB": E_MODE.LSB,
>     "USB": E_MODE.USB,
>     "DSB": E_MODE.DSB,
>     "CWL": E_MODE.CWL,
>     "CWU": E_MODE.CWU,
>     "FMN": E_MODE.FMN,
>     "AM": E_MODE.AM,
>     "DIGU": E_MODE.DIGU,
>     "SPEC": E_MODE.SPEC,
>     "DIGL": E_MODE.DIGL,
>     "SAM": E_MODE.SAM,
>     "DRM": E_MODE.DRM
> ];

I suggest code similar to:

enum E_MODE {
   LSB,  //  0
   USB,  //  1
   DSB,  //  2
   CWL,  //  3
   CWU,  //  4
   FMN,  //  5
   AM,   //  6
   DIGU, //  7
   SPEC, //  8
   DIGL, //  9
   SAM,  // 10
   DRM   // 11
}

void main() {
   // associative array for translation
   with (E_MODE) immutable auto a_mode = [
           "LSB":  LSB,
           "USB":  USB,
           "DSB":  DSB,
           "CWL":  CWL,
           "CWU":  CWU,
           "FMN":  FMN,
           "AM":   AM,
           "DIGU": DIGU,
           "SPEC": SPEC,
           "DIGL": DIGL,
           "SAM":  SAM,
           "DRM":  DRM
       ];
}

Bye,
bearophile
October 05, 2010
Re: Associative arrays give compile error
> enum E_MODE {
>     LSB,  //  0
>     USB,  //  1
>     DSB,  //  2
>     CWL,  //  3
>     CWU,  //  4
>     FMN,  //  5
>     AM,   //  6
>     DIGU, //  7
>     SPEC, //  8
>     DIGL, //  9
>     SAM,  // 10
>     DRM   // 11
> }
> 
> void main() {
>     // associative array for translation
>     with (E_MODE) immutable auto a_mode = [
>             "LSB":  LSB,
>             "USB":  USB,
>             "DSB":  DSB,
>             "CWL":  CWL,
>             "CWU":  CWU,
>             "FMN":  FMN,
>             "AM":   AM,
>             "DIGU": DIGU,
>             "SPEC": SPEC,
>             "DIGL": DIGL,
>             "SAM":  SAM,
>             "DRM":  DRM
>         ];
> }

That code of mine is not good. The following version is more DRY, and in theory it's a better, but in practice it doesn't work:


import std.stdio: writeln;

enum E_MODE {
   LSB,
   USB,
   DSB,
   CWL,
   CWU,
   FMN,
   AM,
   DIGU,
   SPEC,
   DIGL,
   SAM,
   DRM
}

/*immutable*/ E_MODE[string] a_mode;

static this () {
   foreach (m; __traits(allMembers, E_MODE))
       mixin(`a_mode["` ~ m ~ `"] = E_MODE.` ~ m ~ `;`);
}

void main() {
   writeln(a_mode);
}

Bye,
bearophile
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