lazy
Note
This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information.
Returns a lazy, access elements only when needed view of the current
ImmSet
public function lazy(): KeyedIterable<arraykey, Tv>;
Normally, memory is allocated for all of the elements of an ImmSet. With
a lazy view, memory is allocated for an element only when needed or used
in a calculation like in map() or filter().
Guide
Returns
KeyedIterable<arraykey,Tv>- anKeyedIterablerepresenting the lazy view into the currentImmSet, where the keys are the same as the values.
Examples
See Set::lazy for usage examples.