• Paul (17/17) Jun 14 2023 I found I can check for key membership in a multi-D aa...
• Basile B. (2/19) Jun 14 2023 `&&`
• Steven Schveighoffer (16/34) Jun 14 2023 Not in as short code. You could write a helper though:
• Paul (3/19) Jun 14 2023 Thanks Steve.

Paul <phshaffer gmail.com> writes:

I found I can check for key membership in a multi-D aa...
```d
byte zKey = someval;
byte[byte][byte][byte] cubelist;

foreach(byte xK, yzcubelist; cubelist) {
   foreach(byte yK, zcubelist; yzcubelist) {
     foreach(byte zK, val; zcubelist) {
```
with this expression...
```d
     if(zKey in cubelist[xK][yK])
```
Is there a way to check for membership in the x & y dimensions?
```d
     if(yKey in cubelist[xK] ??? [zK])
```
*Thanks in advance for any ideas or solutions.*

Basile B. <b2.temp gmx.com> writes:

On Thursday, 15 June 2023 at 01:47:45 UTC, Paul wrote:
 I found I can check for key membership in a multi-D aa...
 ```d
 byte zKey = someval;
 byte[byte][byte][byte] cubelist;

 foreach(byte xK, yzcubelist; cubelist) {
   foreach(byte yK, zcubelist; yzcubelist) {
     foreach(byte zK, val; zcubelist) {
 ```
 with this expression...
 ```d
     if(zKey in cubelist[xK][yK])
 ```
 Is there a way to check for membership in the x & y dimensions?
 ```d
     if(yKey in cubelist[xK] ??? [zK])
 ```
 *Thanks in advance for any ideas or solutions.*

`&&`

Steven Schveighoffer <schveiguy gmail.com> writes:

On 6/14/23 9:47 PM, Paul wrote:
 I found I can check for key membership in a multi-D aa...
 ```d
 byte zKey = someval;
 byte[byte][byte][byte] cubelist;
 
 foreach(byte xK, yzcubelist; cubelist) {
    foreach(byte yK, zcubelist; yzcubelist) {
      foreach(byte zK, val; zcubelist) {
 ```
 with this expression...
 ```d
      if(zKey in cubelist[xK][yK])
 ```
 Is there a way to check for membership in the x & y dimensions?
 ```d
      if(yKey in cubelist[xK] ??? [zK])
 ```
 *Thanks in advance for any ideas or solutions.*

Not in as short code. You could write a helper though:

```d
auto deepIn(V, K, Keys...)(V[K] aa, Keys keys) if (Keys.length > 0)
{
    auto v = keys[0] in aa;
    static if(keys.length == 1)
      return v;
    else
      return v ? deepIn(*v, keys[1 .. $]) : null;
}

if(auto v = cubelist.deepIn(xKey, yKey, zKey)) { // v now points at the 
value
}
```

-Steve

Paul <phshaffer gmail.com> writes:

On Thursday, 15 June 2023 at 02:21:16 UTC, Steven Schveighoffer 
wrote:
 Not in as short code. You could write a helper though:

 ```d
 auto deepIn(V, K, Keys...)(V[K] aa, Keys keys) if (Keys.length
 0)

 {
    auto v = keys[0] in aa;
    static if(keys.length == 1)
      return v;
    else
      return v ? deepIn(*v, keys[1 .. $]) : null;
 }

 if(auto v = cubelist.deepIn(xKey, yKey, zKey)) { // v now 
 points at the value
 }
 ```

 -Steve

Thanks Steve.