Returns an Awaitable of Vector of ResultOrExceptionWrapper after a mapping operation has been applied to each key/value pair in the provided KeyedTraversable

namespace HH\Asio;

function vmkw<Tk, Tv, Tr>(
  KeyedTraversable<Tk, Tv> $inputs,
  (function(Tk, Tv): Awaitable<Tr>) $callable,
): Awaitable<Vector<ResultOrExceptionWrapper<Tr>>>;

This function is similar to vmk(), except the Vector in the returned Awaitable contains ResultOrExceptionWrappers instead of raw values.

This function is similar to Vector::mapWithKey(), but the mapping of the key/value pairs are done using Awaitables.

This function is called vmkw because we are returning a vector, doing a mapping operation that includes both keys and values, and each member of the Vector is wrapped by a ResultOrExceptionWrapper.

$callable must return an Awaitable.

The ResultOrExceptionWrappers in the Vector of the returned Awaitable are not available until you await or join the returned Awaitable.




async function basic_usage_main(): Awaitable<void> {
  // Map a vector of numbers to their value divided by their index
  // throwing on division by zero.
  $quotients = await \HH\Asio\vmkw(
    Vector {1, 2, 6, 12},

    async ($idx, $val) ==> {
      if ($idx != 0) {
        return $val / $idx;
      } else {
        throw new \Exception(
          "Division by zero: ".\print_r($val, true).'/'.\print_r($idx, true),

  foreach ($quotients as $result) {
    if ($result->isSucceeded()) {
      echo "Success: ";
    } else {
      echo "Failed: ";