Menu
Search

Forums

Forum Index

Thread overview
key membership in multi-dimensional assoc. array
Jun 15, 2023
Paul
Jun 15, 2023
Basile B.
Jun 15, 2023
Paul
June 15, 2023
Gravatar of PaulPosted by PaulReply
Paul
Gravatar of Paul


Reply

I found I can check for key membership in a multi-D aa...

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...

    if(zKey in cubelist[xK][yK])

Is there a way to check for membership in the x & y dimensions?

    if(yKey in cubelist[xK] ??? [zK])

Thanks in advance for any ideas or solutions.

June 15, 2023
Gravatar of Basile B.Posted by Basile B.
in reply to Paul		Reply
Basile B.
Gravatar of Basile B.
Posted in reply to Paul


Reply

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...

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...

    if(zKey in cubelist[xK][yK])

Is there a way to check for membership in the x & y dimensions?

    if(yKey in cubelist[xK] ??? [zK])

Thanks in advance for any ideas or solutions.

&&

June 14, 2023
Gravatar of Steven SchveighofferPosted by Steven Schveighoffer
in reply to Paul		Reply
Steven Schveighoffer
Gravatar of Steven Schveighoffer
Posted in reply to Paul


Reply

On 6/14/23 9:47 PM, Paul wrote:

>

I found I can check for key membership in a multi-D aa...

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...

     if(zKey in cubelist[xK][yK])

Is there a way to check for membership in the x & y dimensions?

     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:

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

June 15, 2023
Gravatar of PaulPosted by Paul
in reply to Steven Schveighoffer		Reply
Paul
Gravatar of Paul
Posted in reply to Steven Schveighoffer


Reply

On Thursday, 15 June 2023 at 02:21:16 UTC, Steven Schveighoffer wrote:

>

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

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.