Array decomposition, more than list()

I've been using array decomposition in other languages such as Javascript recently and find it very useful. I did not find any conversation about it in the archives, has this topic been discussed/vetted/shot down already? Example use case: Indexed database results being iterated: Input: $tValues[$dbRow['ID1']][$dbRow['ID2']][$dbRow['ID3']] = $dbRow['Value']; Output: foreach($tValues as $ID1 => $tSubValues1) { foreach($tSubValues1 as $ID2 => $tSubValues2) { foreach($tSubValues2 as $ID3 => $Value) { /* Do something, such as build an SQL insert */ } } } The above is a semi-common piece of code in our production application, I could see list decomposition as a very convenient alternative. New functionality would support: foreach($tValues as $ID1 => [$ID2 => [$ID3 => $Value] ]) { /* Do something */ } The above also would indicate that associative array key decomposition would also be allowed. I don't believe anything like the above is possible, even outside of a foreach loop, but perhaps I am wrong there. What do you think? -Clint