Associative arrays give compile error

Tue Oct 5 05:04:06 PDT 2010

On Tue, 05 Oct 2010 15:50:44 +0400, Bob Cowdery <bob at 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 at 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 at 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 at 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.