On Friday, 17 October 2014 at 17:57:58 UTC, Tofu Ninja wrote:
> On Friday, 17 October 2014 at 17:44:48 UTC, Tofu Ninja wrote:
>
> Not sure if what I wrote made sense, instead I will just post the code that is vomiting on me...

You forgot the imports.

> template arrayType(T)
> {
> 	alias arrayType = T[];
> }
>
> template multiAccess(Args ...)
> {
> 	auto multiAccess(int i, staticMap!(arrayType, Args) args)
> 	{
> 		static if(args.length == 1) return Tuple!(args[0][i]);

`Tuple` is a type template. Use `tuple(foo, bar)` to build a
`Tuple!(typeof(foo), typeof(bar))`.

=> return tuple(args[0][i]);

> 		else return Tuple!(args[0][i], multiAccess!(Args[1 .. $])(args[1 .. $]));

`Tuple!` -> `tuple` again. Also, `multiAccess` needs `i` again.
And you want to `expand` the sub-result into the tuple so that
it's flat.

=> return tuple(args[0][i], multiAccess!(Args[1 .. $])(i, args[1
.. $]).expand);

> 	}
> }
>
> void main(string[] args)
> {
> 	int[] a = [1,2];
> 	int[] b = [5,6];
> 	writeln(multiAccess!(int,int)(1, a,b));
> }
>
> but the compiler really does not like that at all... the error message are very unhelpful as well...
>
> Generates 18 errors...
>
> main.d(52): Error: variable _param_1 cannot be read at compile time
[...]

This is about you trying to instantiate `Tuple` with the runtime
value that is `args[0][1]`.

> main.d(52): Error: tuple index 0 exceeds length 0
[...]

I don't know where these come from. They don't show up for me.

> main.d(53): Error: template instance main.multiAccess!() error instantiating
[...]

These are due to previous errors.


For style points you could

* Use the short form for function templates:

     auto multiAccess(Args ...)(int i, staticMap!(arrayType, Args)
args) {...}

* Take array types as template arguments instead of constructing
them. This allows them to be inferred (IFTI - Implicit Function
Template Instantiation):

     auto multiAccess(Args ...)(int i, Args args)
         /* Maybe put a template constraint here that forces Args
to be all arrays. */
     {
         import std.typecons: tuple;
         static if(args.length == 1) return tuple(args[0][i]);
         else return tuple(args[0][i], multiAccess(i, args[1 ..
$]).expand);
     }
     void main()
     {
         int[] a = [1,2];
         int[] b = [5,6];
         import std.stdio;
         writeln(multiAccess(1, a,b));
     }

On Friday, 17 October 2014 at 19:03:42 UTC, anonymous wrote:
> On Friday, 17 October 2014 at 17:57:58 UTC, Tofu Ninja wrote:
>> On Friday, 17 October 2014 at 17:44:48 UTC, Tofu Ninja wrote:
>>
>> Not sure if what I wrote made sense, instead I will just post the code that is vomiting on me...
>
> You forgot the imports.
>
>> template arrayType(T)
>> {
>> 	alias arrayType = T[];
>> }
>>
>> template multiAccess(Args ...)
>> {
>> 	auto multiAccess(int i, staticMap!(arrayType, Args) args)
>> 	{
>> 		static if(args.length == 1) return Tuple!(args[0][i]);
>
> `Tuple` is a type template. Use `tuple(foo, bar)` to build a
> `Tuple!(typeof(foo), typeof(bar))`.
>
> => return tuple(args[0][i]);
>
>> 		else return Tuple!(args[0][i], multiAccess!(Args[1 .. $])(args[1 .. $]));
>
> `Tuple!` -> `tuple` again. Also, `multiAccess` needs `i` again.
> And you want to `expand` the sub-result into the tuple so that
> it's flat.
>
> => return tuple(args[0][i], multiAccess!(Args[1 .. $])(i, args[1
> .. $]).expand);
>
>> 	}
>> }
>>
>> void main(string[] args)
>> {
>> 	int[] a = [1,2];
>> 	int[] b = [5,6];
>> 	writeln(multiAccess!(int,int)(1, a,b));
>> }
>>
>> but the compiler really does not like that at all... the error message are very unhelpful as well...
>>
>> Generates 18 errors...
>>
>> main.d(52): Error: variable _param_1 cannot be read at compile time
> [...]
>
> This is about you trying to instantiate `Tuple` with the runtime
> value that is `args[0][1]`.
>
>> main.d(52): Error: tuple index 0 exceeds length 0
> [...]
>
> I don't know where these come from. They don't show up for me.
>
>> main.d(53): Error: template instance main.multiAccess!() error instantiating
> [...]
>
> These are due to previous errors.
>
>
> For style points you could
>
> * Use the short form for function templates:
>
>      auto multiAccess(Args ...)(int i, staticMap!(arrayType, Args)
> args) {...}
>
> * Take array types as template arguments instead of constructing
> them. This allows them to be inferred (IFTI - Implicit Function
> Template Instantiation):
>
>      auto multiAccess(Args ...)(int i, Args args)
>          /* Maybe put a template constraint here that forces Args
> to be all arrays. */
>      {
>          import std.typecons: tuple;
>          static if(args.length == 1) return tuple(args[0][i]);
>          else return tuple(args[0][i], multiAccess(i, args[1 ..
> $]).expand);
>      }
>      void main()
>      {
>          int[] a = [1,2];
>          int[] b = [5,6];
>          import std.stdio;
>          writeln(multiAccess(1, a,b));
>      }

I had the imports, I just didn't post them. My problem is most likely that I used Tuple! instead of tuple... which is probably because the differences between the like 20(exaggeration) different types of tuples in D are confusing as hell...

On Friday, 17 October 2014 at 19:18:29 UTC, Tofu Ninja wrote:
> I had the imports, I just didn't post them. My problem is most likely that I used Tuple! instead of tuple... which is probably because the differences between the like 20(exaggeration) different types of tuples in D are confusing as hell...

You've seen the rest of my message, right?

On Fri, 17 Oct 2014 11:56:31 -0700, Ali Çehreli wrote:

> You want to write a function that takes an index and a number of arrays; and returns an N-ary Tuple where N matches the number arrays passed to the function: :p

http://dlang.org/phobos/std_range.html#transversal

On Friday, 17 October 2014 at 19:32:40 UTC, anonymous wrote:
> On Friday, 17 October 2014 at 19:18:29 UTC, Tofu Ninja wrote:
>> I had the imports, I just didn't post them. My problem is most likely that I used Tuple! instead of tuple... which is probably because the differences between the like 20(exaggeration) different types of tuples in D are confusing as hell...
>
> You've seen the rest of my message, right?

Yeah, the part that fixed it was Tuple! to tuple. Thanks for the help. I think this fixes my problem.

On Fri, 17 Oct 2014 20:25:26 +0000, Tofu Ninja wrote:

> Yeah, the part that fixed it was Tuple! to tuple. Thanks for the help. I think this fixes my problem.

I think std.range.transversal already provides the functionality you're
looking for.
http://dlang.org/phobos/std_range.html#transversal