Hi,

i want to save data from an array of variants into a file. I saw that to!string format the array content in a nice way... There is a way of converting the resulted string back to an array of varianta?

thanks,
Bogdan

On 08/31/2013 10:22 PM, gedaiu wrote:> Hi,
>
> i want to save data from an array of variants into a file. I saw that
> to!string format the array content in a nice way...

I don't think the format is sufficient for recreating the array:

import std.variant;
import std.conv;
import std.stdio;

struct S
{
    int i;
}

void main()
{
    auto a = [ Variant(42), Variant("hello"), Variant(S(5)) ];
    writeln(a);
}

Outputs:

[42, hello, S(5)]

We can only guess that 'hello' is a string but what if it were the string "43"? It would look like an int. Also, any type can overload toString; so, S(5) could output itself as e.g. "world".

> There is a way of
> converting the resulted string back to an array of varianta?

This requires a serialization module. std.serialization is in review right now:

  http://forum.dlang.org/post/hsnmxykmoytfvwroikzk@forum.dlang.org

Its author Jacob Carlborg already has a serialization module called Orange:

  https://github.com/jacob-carlborg/orange

>
> thanks,
> Bogdan

Ali

Thanks for the response... I thought there is a faster way for that. I will use the standard lib or i will use json to store that into a file.


Thanks,
Bogdan




On Sunday, 1 September 2013 at 16:19:32 UTC, Ali Çehreli wrote:
> On 08/31/2013 10:22 PM, gedaiu wrote:> Hi,
> >
> > i want to save data from an array of variants into a file. I
> saw that
> > to!string format the array content in a nice way...
>
> I don't think the format is sufficient for recreating the array:
>
> import std.variant;
> import std.conv;
> import std.stdio;
>
> struct S
> {
>     int i;
> }
>
> void main()
> {
>     auto a = [ Variant(42), Variant("hello"), Variant(S(5)) ];
>     writeln(a);
> }
>
> Outputs:
>
> [42, hello, S(5)]
>
> We can only guess that 'hello' is a string but what if it were the string "43"? It would look like an int. Also, any type can overload toString; so, S(5) could output itself as e.g. "world".
>
> > There is a way of
> > converting the resulted string back to an array of varianta?
>
> This requires a serialization module. std.serialization is in review right now:
>
>   http://forum.dlang.org/post/hsnmxykmoytfvwroikzk@forum.dlang.org
>
> Its author Jacob Carlborg already has a serialization module called Orange:
>
>   https://github.com/jacob-carlborg/orange
>
> >
> > thanks,
> > Bogdan
>
> Ali