Hi everyone,

I'm trying to something like a tree structure.

The following:

import std.container;
class Tree
{
        private SList!Tree subTree;
}

Produces: class Tree no size yet for forward reference.

How i should proceed in order to keep this declaration?

Thanks a lot!

PD: (You guys are incredibly quick to answer, that's awesome!)

On Thursday, 9 October 2014 at 19:04:56 UTC, Anibal wrote:
> Hi everyone,
>
> I'm trying to something like a tree structure.
>
> The following:
>
> import std.container;
> class Tree
> {
>         private SList!Tree subTree;
> }
>
> Produces: class Tree no size yet for forward reference.
>
> How i should proceed in order to keep this declaration?
>
> Thanks a lot!
>
> PD: (You guys are incredibly quick to answer, that's awesome!)

make a pointer list instead, which has a fixed size:
---
import std.container;
class Tree
{
        private SList!(Tree*) subTree;
}
---

On Thu, 09 Oct 2014 19:04:55 +0000
Anibal via Digitalmars-d-learn <digitalmars-d-learn@puremagic.com>
wrote:

> Hi everyone,
> 
> I'm trying to something like a tree structure.
> 
> The following:
> 
> import std.container;
> class Tree
> {
>          private SList!Tree subTree;
> }
> 
> Produces: class Tree no size yet for forward reference.
> 
> How i should proceed in order to keep this declaration?
do you really need single-linked list for that? D has dynamic arrays, which can be used instead.

  class Tree {
    private Tree[] subTree;
  }

you can append items to dynamic array with "~=", get it length with .length and so on.

seems that you trying to copy some C code (or writing in C
manner), amirite? it is possible to use D as "better C", but D has alot
more to offer. did you seen this excellent book:
http://ddili.org/ders/d.en/ ?
it will teach you some nice things which are absent in C. read it even
if you are seasoned C programmer. you'll see a joy of dynamic arrays,
slices, ranges and templates, nicely explained.

On Thursday, 9 October 2014 at 19:29:13 UTC, ketmar via Digitalmars-d-learn wrote:
> On Thu, 09 Oct 2014 19:04:55 +0000
> Anibal via Digitalmars-d-learn <digitalmars-d-learn@puremagic.com>
> wrote:
>
>> Hi everyone,
>> 
>> I'm trying to something like a tree structure.
>> 
>> The following:
>> 
>> import std.container;
>> class Tree
>> {
>>          private SList!Tree subTree;
>> }
>> 
>> Produces: class Tree no size yet for forward reference.
>> 
>> How i should proceed in order to keep this declaration?
> do you really need single-linked list for that? D has dynamic arrays,
> which can be used instead.
>
>   class Tree {
>     private Tree[] subTree;
>   }
>
> you can append items to dynamic array with "~=", get it length
> with .length and so on.
>
> seems that you trying to copy some C code (or writing in C
> manner), amirite? it is possible to use D as "better C", but D has alot
> more to offer. did you seen this excellent book:
> http://ddili.org/ders/d.en/ ?
> it will teach you some nice things which are absent in C. read it even
> if you are seasoned C programmer. you'll see a joy of dynamic arrays,
> slices, ranges and templates, nicely explained.

Thanks a lot, declaring it as an array solved mi troubles!

On Thursday, 9 October 2014 at 19:26:20 UTC, Njkp wrote:
> On Thursday, 9 October 2014 at 19:04:56 UTC, Anibal wrote:
>> Hi everyone,
>>
>> I'm trying to something like a tree structure.
>>
>> The following:
>>
>> import std.container;
>> class Tree
>> {
>>        private SList!Tree subTree;
>> }
>>
>> Produces: class Tree no size yet for forward reference.
>>
>> How i should proceed in order to keep this declaration?
>>
>> Thanks a lot!
>>
>> PD: (You guys are incredibly quick to answer, that's awesome!)
>
> make a pointer list instead, which has a fixed size:
> ---
> import std.container;
> class Tree
> {
>         private SList!(Tree*) subTree;
> }
> ---
fixed size: the item as pointer. But, BTW if you put a class as an item collection it's always a fixed size, a class is always a ptr. Better, you 'll be able to use the pointer without dereference.

But you prefear the solution of the other guy...It's ok. I just hope that your subtree will not have to be reorganized too often...because with an array, it'll be very very very slow...