Apologies if this has been answered, but I couldn't find a reference.

I am trying to define an associative array, keyed on int[], of int[].
I have tried:
int[int[]][] x;

which compiles OK.

Attempting to use x causes errors.
int[4] y;
if(!y in x) {
x[y].length = 0; // initialise x[y]
}

What are your thoughts?

Darcy Currey

Darcy Currey wrote:
> Apologies if this has been answered, but I couldn't find a reference.
> 
> I am trying to define an associative array, keyed on int[], of int[].
> I have tried:
> int[int[]][] x;

x is an array of (assoc array which maps int[] to int)
this is not what you wanted.
D arrays declare are reversed so that
typedef foo[B] elem;
elem[A] x;
is the same as foo[B][A] x
unlike C where is would be
elem x[A] => foo x[A][B]

> 
> which compiles OK.


> 
> Attempting to use x causes errors.
> int[4] y;
> if(!y in x) {
> x[y].length = 0; // initialise x[y]
> }
> 
> What are your thoughts?

try `int[][int[]] x;`

x is assoc array mapping int[] to int[]

> 
> Darcy Currey

Darcy Currey wrote:
> 
> Apologies if this has been answered, but I couldn't find a reference.
> 
> I am trying to define an associative array, keyed on int[], of int[].
> I have tried:
> int[int[]][] x;
> 
> which compiles OK.
> 
> Attempting to use x causes errors.
> int[4] y;
> if(!y in x) {
> x[y].length = 0; // initialise x[y]
> }
> 
> What are your thoughts?
> 
> Darcy Currey

Perhaps this way:

========================

int [][int[]] x;

int [4] y= [1,11,21,31];
int [4] z= [21,20,19,18];

int main() {

  x[y]=z;
  x[z]=y;

  int [][] keys=x.keys;
  int [] key;
  int [] val;

  for(int i=0; i<keys.length; i++) {
    key=keys[i];
    val=x[key];
    printf("%d: key: ",i);
       for(int j=0; j<key.length; j++) printf("%d ",key[j]);
    printf("val: ");
       for(int j=0; j<val.length; j++) printf("%d ",val[j]);
    printf("\n",i);
  }
  return 0;
}

=========================

Output:

  0: key: 1 11 21 31 val: 21 20 19 18
  1: key: 21 20 19 18 val: 1 11 21 31


-- 
Helmut Leitner    leitner@hls.via.at
Graz, Austria   www.hls-software.com