HH\Asio\vm
Returns an Awaitable of Vector containing after a mapping operation has
been applied to each value in the provided Traversable
namespace HH\Asio;
function vm<Tv, Tr>(
Traversable<Tv> $inputs,
(function(Tv): Awaitable<Tr>) $callable,
): Awaitable<Vector<Tr>>;
This function is similar to Vector::map(), but the mapping of the values
is done using Awaitables.
This function is called vm because we are returning a vector, and
we are doing a mapping operation.
$callable must return an Awaitable.
The values in the Vector of the returned Awaitable are not available
until you await or join the returned Awaitable.
Parameters
Traversable<Tv> $inputs- TheTraversableof values to map.(function(Tv): Awaitable<Tr>) $callable- The callable containing theAwaitableoperation to apply to$inputs.
Returns
Awaitable<Vector<Tr>>- AnAwaitableofVectorafter the mapping operation has been applied to the values in$inputs.
Examples
/**
* Query an arbitrary number of URLs in parallel
* returning them as a Vector of string responses.
*
* Refer to \HH\Asio\v() for a more verbose version of this.
*/
async function get_urls(\ConstVector<string> $urls): Awaitable<Vector<string>> {
// Invoke \HH\Asio\curl_exec for each URL,
// then await on each in parallel
return await \HH\Asio\vm($urls, fun("\HH\Asio\curl_exec"));
}
$urls = ImmVector {
"http://example.com",
"http://example.net",
"http://example.org",
};
$pages = \HH\Asio\join(get_urls($urls));
foreach ($pages as $page) {
echo substr($page, 0, 15).' ... '.substr($page, -8);
}
<!doctype html> ... </html>
<!doctype html> ... </html>
<!doctype html> ... </html>