DocumentationHackReferenceClassHH\MaptoImmVector

HH\Map::toImmVector

Returns an immutable vector (ImmVector) with the values of the current Map

public function toImmVector(): ImmVector<Tv>;

Returns

ImmVector<Tv> - an ImmVector that is an immutable copy of the current Map.

Examples

This example shows that toImmVector returns an immutable copy of the Map's values. Mutating the Vector of values doesn't affect the original Map and vice-versa.

$m = Map {
  'red' => '#ff0000',
  'green' => '#00ff00',
  'blue' => '#0000ff',
  'yellow' => '#ffff00',
};

function expects_immutable(ImmVector<string> $iv): void {
  \var_dump($iv);
}

// Get an immutable Vector of $m's values
$immutable_v = $m->toImmVector();

// Add a color to the original Map $m
$m->add(Pair {'purple', '#663399'});

expects_immutable($immutable_v);

Output

object(HH\ImmVector)#2 (4) {
  [0]=>
  string(7) "#ff0000"
  [1]=>
  string(7) "#00ff00"
  [2]=>
  string(7) "#0000ff"
  [3]=>
  string(7) "#ffff00"
}