Is there an easy way to output a struct's contents?
e.g. member1: value1, member2: value2, ...
I have a really big struct and formatting it all by hand would be time-consuming.

On Wed, Jan 14, 2009 at 4:57 PM, Hoenir <mrmocool@gmx.de> wrote:
> Is there an easy way to output a struct's contents?
> e.g. member1: value1, member2: value2, ...
> I have a really big struct and formatting it all by hand would be
> time-consuming.
>

bearophile has apparently done so in his "libs" but I have no idea where you can download that.

Reply to Hoenir,

> Is there an easy way to output a struct's contents?
> e.g. member1: value1, member2: value2, ...
> I have a really big struct and formatting it all by hand would be
> time-consuming.

http://codepad.org/Eu16XqFu

BCS schrieb:
> http://codepad.org/Eu16XqFu
> 

Thank you very much, it works like a charm.
I wrote a small function to log whatever object I pass to it:

void log(T)(T obj)
{
	static if (is(T == struct) || is(T == class))
	{
		writef("{");
		foreach(i,_;obj.tupleof)
			writefln("%s : %s,", obj.tupleof[i].stringof[4..$], obj.tupleof[i]);
		writefln("}");
	}
	else
	{
		writefln(obj);
	}
}

Are there better solutions than this or does it perhaps have any flaws?

On Thu, 15 Jan 2009 03:04:15 +0300, Hoenir <mrmocool@gmx.de> wrote:

> BCS schrieb:
>> http://codepad.org/Eu16XqFu
>>
>
> Thank you very much, it works like a charm.
> I wrote a small function to log whatever object I pass to it:
>
> void log(T)(T obj)
> {
> 	static if (is(T == struct) || is(T == class))
> 	{
> 		writef("{");
> 		foreach(i,_;obj.tupleof)
> 			writefln("%s : %s,", obj.tupleof[i].stringof[4..$], obj.tupleof[i]);
> 		writefln("}");
> 	}
> 	else
> 	{
> 		writefln(obj);
> 	}
> }
>
> Are there better solutions than this or does it perhaps have any flaws?

One note is that you should probably pass the object by reference:

void log(T)(ref T obj) { ... }        // D1
void log(T)(ref const(T) obj) { ... } // D2

Jarrett Billingsley:
> bearophile has apparently done so in his "libs" but I have no idea where you can download that.

If you use Phobos on D1 the d.string.put/putr to print generic structs, or use a d.templates.Record struct: http://www.fantascienza.net/leonardo/so/libs_d.zip

Bye,
bearophile

Denis Koroskin schrieb:
> One note is that you should probably pass the object by reference:
> 
> void log(T)(ref T obj) { ... }        // D1
> void log(T)(ref const(T) obj) { ... } // D2
> 

Good idea. btw ref'ing a class has no effect, has it?

Actually discovered a flaw, if you e.g. pass an array of structs to it, dmd complains about the struct not having a toString() member.

So it needs to be recursive somehow.

Reply to Hoenir,

> Denis Koroskin schrieb:
> 
>> One note is that you should probably pass the object by reference:
>> 
>> void log(T)(ref T obj) { ... }        // D1
>> void log(T)(ref const(T) obj) { ... } // D2
> Good idea. btw ref'ing a class has no effect, has it?
> 

ref object would allow you to alter what the passed in argument is:


 void Fn(ref object o) { o = null; }

 object o = new Bah!();
 Fn(o);
 assert(o is null);


> Actually discovered a flaw, if you e.g. pass an array of structs to
> it, dmd complains about the struct not having a toString() member.
> 
> So it needs to be recursive somehow.
> 

I have a partial solution here:  http://www.dsource.org/projects/scrapple/browser/trunk/log_api/LogAPI.d 


Feel free to steal whatever you want from it. If you are really adventures and want to, I can get you SVN access and you can dump stuff back into that.

Hoenir:
> So it needs to be recursive somehow.

The stuff I have linked you is recursive, of course.

Bye,
bearophile

BCS schrieb:
> Reply to Hoenir,
> 
>> Denis Koroskin schrieb:
>>
>>> One note is that you should probably pass the object by reference:
>>>
>>> void log(T)(ref T obj) { ... }        // D1
>>> void log(T)(ref const(T) obj) { ... } // D2
>> Good idea. btw ref'ing a class has no effect, has it?
>>
> 
> ref object would allow you to alter what the passed in argument is:
> 
> 
>  void Fn(ref object o) { o = null; }
> 
>  object o = new Bah!();
>  Fn(o);
>  assert(o is null);
> 

Oh, yeah of course, forgot that. Was just thinking of structs being value and classes being reference types.