HH\ImmSet::mapWithKey

Returns an ImmSet containing the values after an operation has been applied to each "key" and value in the current ImmSet.

Description

public function mapWithKey(
  callable $callback,
): ImmSet<Tu>

Returns an ImmSet containing the values after an operation has been applied to each "key" and value in the current ImmSet.

Since ImmSets don't have keys, the callback uses the values as the keys as well.

Every value in the current ImmSet is affected by a call to mapWithKey(), unlike filterWithKey() where only values that meet a certain criteria are affected.

Parameters

  • callable $callback - The callback containing the operation to apply to the current ImmSet keys and values.

Return Values

  • ImmSet<Tu> - an ImmSet containing the values after a user-specified operation on the current ImmSet's values is applied.

Examples

See Set::mapWithKey for usage examples.