HH\Asio\vmkw

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.

Parameters

• KeyedTraversable<Tk, Tv> $inputs - The KeyedTraversable of keys and values to map.
• (function(Tk, Tv): Awaitable<Tr>) $callable - The callable containing the Awaitable operation to apply to $inputs.

Returns

• Awaitable<Vector<ResultOrExceptionWrapper<Tr>>> - An Awaitable of Vector of ResultOrExceptionWrapper after the mapping operation has been applied to the keys and values in $inputs.

Examples

// Map a vector of numbers to their value divided by their index
// throwing on division by zero.
$quotients = \HH\Asio\join(\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: ";
    var_dump($result->getResult());
  } else {
    echo "Failed: ";
    var_dump($result->getException()->getMessage());
  }
}

Failed: string(21) "Division by zero: 1/0"
Success: int(2)
Success: int(3)
Success: int(4)