HH\ImmMap::takeWhile

Returns an ImmMap containing the keys and values of the current ImmMap up to but not including the first value that produces false when passed to the specified callback

public function takeWhile(
  (function(Tv): bool) $callback,
): ImmMap<Tk, Tv>;

The returned ImmMap will always be a proper subset of the current ImmMap.

Parameters

• (function(Tv): bool) $callback

Returns

• ImmMap<Tk,Tv> - An ImmMap that is a proper subset of the current ImmMap up until when the callback returns false.

Examples

See [Map::takeWhile](</hack/reference/class/Map/takeWhile/#examples>) for usage examples.