HH\Asio\mmkw
Returns an Awaitable of Map of ResultOrExceptionWrapper after a
mapping operation has been applied to each key/value pair in the provided
KeyedTraversable
namespace HH\Asio;
function mmkw<Tk as arraykey, Tv, Tr>(
KeyedTraversable<Tk, Tv> $inputs,
(function(Tk, Tv): Awaitable<Tr>) $callable,
): Awaitable<Map<Tk, ResultOrExceptionWrapper<Tr>>>;
This function is similar to mmk(), except the Map in the returned
Awaitable contains values of ResultOrExceptionWrapper instead of raw
values.
This function is similar to Map::mapWithKey(), but the mapping of the keys
and values is done using Awaitables.
This function is called mmkw because we are returning a map, doing a
mapping operation on keys and values, and each value member in the Map
is wrapped by a ResultOrExceptionWrapper.
$callable must return an Awaitable.
The ResultOrExceptionWrappers in the Map of the returned Awaitable
are not available until you await or join the returned Awaitable.
Parameters
KeyedTraversable<Tk, Tv> $inputs- TheKeyedTraversableof keys and values to map.(function(Tk, Tv): Awaitable<Tr>) $callable- The callable containing theAwaitableoperation to apply to$inputs.
Returns
Awaitable<Map<Tk, ResultOrExceptionWrapper<Tr>>>- AnAwaitableofMapof key/ResultOrExceptionWrapperpairs after the mapping operation has been applied to the keys an values in$inputs.
Examples
// Map a vector of numbers to their value divided by their index
// throwing on division by zero.
$quotients = \HH\Asio\join(\HH\Asio\mmkw(
Map {
1 => 1,
0 => 2,
2 => 6,
3 => 12,
},
async ($div, $val) ==> {
if ($div != 0) {
return $val / $div;
} else {
throw new \Exception(
"Division by zero: ".print_r($val, true).'/'.print_r($div, true),
);
}
},
));
foreach ($quotients as $result) {
if ($result->isSucceeded()) {
echo " Success: ";
var_dump($result->getResult());
} else {
echo "Failed: ";
var_dump($result->getException()->getMessage());
}
}
Success: int(1)
Failed: string(21) "Division by zero: 2/0"
Success: int(3)
Success: int(4)