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));
}
