Hello, i am new in D and i have a problem.
I would like to retrieve the names of the variables and their value.
But i can not retrieve the value of the array.

class Test
{
    public int a;
    public Test[] b;

    this()
    {
      a = 1;
      b = [new Test(), new Test()];
    }
}

//======================================================================

void Read(T)(T value)
{
   foreach(i, mm; value.tupleof)
   {
      writeln(__traits(identifier, value.tupleof[i]), " = ", mm);

      if(isArray!(typeof(mm)))
      {
          Read(mm[0]); //Error
      }
   }
}

void main(string[] args)
{
   Read(new Test());
}

Thank you for your help.

On Wednesday, 22 February 2017 at 18:34:26 UTC, houdoux09 wrote:
> void Read(T)(T value)
> {
>    foreach(i, mm; value.tupleof)
>    {
>       writeln(__traits(identifier, value.tupleof[i]), " = ", mm);
>
>       if(isArray!(typeof(mm)))
>       {
>           Read(mm[0]); //Error
>       }
>    }
> }

You need to use "static if" here inside foreach. Otherwise the body of your "if" gets compiled for all the different fields of "value" and of course fails for the fields that are not arrays.

Yes thank you it works.

On 2017-02-22 20:13, thedeemon wrote:
> On Wednesday, 22 February 2017 at 18:34:26 UTC, houdoux09 wrote:
>> void Read(T)(T value)
>> {
>>    foreach(i, mm; value.tupleof)
>>    {
>>       writeln(__traits(identifier, value.tupleof[i]), " = ", mm);
>>
>>       if(isArray!(typeof(mm)))
>>       {
>>           Read(mm[0]); //Error
>>       }
>>    }
>> }
>
> You need to use "static if" here inside foreach. Otherwise the body of
> your "if" gets compiled for all the different fields of "value" and of
> course fails for the fields that are not arrays.

I'm pretty sure you need to use "value.tupleof[i][0]" instead of "mm[0]" as well.

-- 
/Jacob Carlborg

> I'm pretty sure you need to use "value.tupleof[i][0]" instead of "mm[0]" as well.


it does not work but I found a solution, that's what I do :

abstract class BaseClass
{
    uint[] a = [9, 10, 5];
}

override class Test : BaseClass
{
   int t = 0;
   string s = "holla";
}

public static JSONValue Serialize(BaseClass value)
{
    foreach(member; __traits(allMembers, typeof(value)))
    {
       static if (__traits(compiles, to!string(__traits(getMember, value, member))))
       {
	  auto result =  __traits(getMember, value, member);
          static if(isArray!(typeof(value)) && !is(typeof(value) == string))
	  {
		// process	
	  }
	  else static if(is(typeof(value) == class) || is(typeof(value) == struct))
	  {
               // process	
          }
          else
          {
              // process	
          }
     }
}

void main(string[] args)
{
   Serialize(new Test());
}

The problem is that I can not retrieve the variables from the parent class.

On 2017-02-24 19:10, houdoux09 wrote:

> The problem is that I can not retrieve the variables from the parent class.

Cast the value to the type of the base class and run it through the same function. You can have a look at the Orange serialization library [1].

[1] https://github.com/jacob-carlborg/orange

-- 
/Jacob Carlborg