HH\Asio\vmk
Returns an Awaitable of Vector after a mapping operation has been
applied to each key and value in the provided KeyedTraversable
namespace HH\Asio;
function vmk<Tk, Tv, Tr>(
KeyedTraversable<Tk, Tv> $inputs,
(function(Tk, Tv): Awaitable<Tr>) $callable,
): Awaitable<Vector<Tr>>;
This function is similar to vm(), but passes element keys to the callable
as well.
This function is similar to Vector::mapWithKey(), but the mapping of the
keys and values is done using Awaitables.
This function is called vmk because we are returning a vector and doing
a mapping operation that includes keys.
$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
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<Vector<Tr>>- AnAwaitableofVectorafter the mapping operation has been applied to both the keys and values in$inputs.
Examples
/**
* Query an arbitrary number of URLs in parallel
* returning them as a Vector of string responses.
*/
async function get_urls(\ConstVector<string> $urls): Awaitable<Vector<string>> {
// Await on curl requests in parallel and
// prepend the request ID index
return await \HH\Asio\vmk(
$urls,
async ($idx, $url) ==> {
$content = await \HH\Asio\curl_exec($url);
return $idx." => ".$content;
},
);
}
$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, 20).' ... '.substr($page, -8);
}
0 => <!doctype html> ... </html>
1 => <!doctype html> ... </html>
2 => <!doctype html> ... </html>