Add keyBy() to key the documents by the given key

[thekid]

This method keys the cursor's documents by the given key, yielding the key / value pairs.

Comparison

Before:

$claims= [];
foreach ($this->claims->find(['user' => $user]) as $claim) {
  $claims[$claim['tenant']]= $claim;
}

After:

$claims= [...$this->claims->find(['user' => $user])->keyBy('tenant')];

Overloads

• keyBy('tenant') - uses the tenant field as keys and the docunents as associated values
• keyBy(['tenant' => 'tokens.access']) will use the tenant field as keys and the access key in the tokens object as values
• keyBy(fn($c) => [$c->get('tenant') => $c]) - same as above but shows the full flexibility
• keyBy(function($c) { yield $c->get('tenant') => $c; }) - also works with generators

Prior art

• https://laravel.com/docs/13.x/collections#method-keyby
• https://www.geeksforgeeks.org/javascript/lodash-_-keyby-method/
• https://kotlinlang.org/api/core/kotlin-stdlib/kotlin.sequences/associate-by.html