Utility Functions
Async can be used effectively with the basic, built in infrastructure in HHVM, along with some HSL functions. This basic infrastructure includes:
However, there are cases when we want to convert some collection of values to awaitables or we want to filter some awaitables out of a collection of awaitables. These types of scenarios come up when we are creating multiple awaitables to await in parallel. Some of the functions that help with this are:
| Name | Returns | Description |
|---|---|---|
HH\Lib\Vec\filter_async<Tv> | Awaitable<vec<Tv>> | Returns a new vec containing only the values for which the given async predicate returns true. |
HH\Lib\Vec\from_async<Tv> | Awaitable<vec<Tv>> | Returns a new vec with each value awaited in parallel. |
HH\Lib\Vec\map_async<Tv1, Tv2> | Awaitable<vec<Tv2>> | Returns a new vec where each value is the result of calling the given async function on the original value. |
HH\Lib\Dict\filter_async<Tk as arraykey, Tv> | Awaitable<dict<Tk,Tv>> | Returns a new dict containing only the values for which the given async predicate returns true. |
HH\Lib\Dict\filter_with_key_async<Tk as arraykey, Tv> | Awaitable<dict<Tk,Tv>> | Like filter_async, but lets you utilize the keys of your dict too. |
HH\Lib\Dict\from_async<Tk, Tv1> | Awaitable<dict<Tk,Tv2>> | Returns a new dict where each value is the result of calling the given async function on the original value. |
HH\Lib\Dict\from_keys_async<Tk as arraykey, Tv> | Awaitable<dict<Tk,Tv>> | Returns a new dict where each value is the result of calling the given async function on the corresponding key. |
HH\Lib\Dict\map_async<Tk as arraykey, Tv1, Tv2> | Awaitable<dict<Tk,Tv2>> | Returns a new dict where each value is the result of calling the given async function on the original value. |
HH\Lib\Keyset\filter_async<Tv as arraykey> | Awaitable<keyset<Tv>> | Returns a new keyset containing only the values for which the given async predicate returns true. |
HH\Lib\Keyset\from_async<Tv as arraykey> | Awaitable<keyset<Tv>> | Returns a new keyset containing the awaited result of the given Awaitables. |
HH\Lib\Keyset\map_async<Tv, Tk as arraykey> | Awaitable<keyset<Tk>> | Returns a new keyset where the value is the result of calling the given async function on the original values in the given traversable. |
Other Convenience Functions
There are three convenience-functions tailored for use with async. They are:
| Name | Returns | Description |
|---|---|---|
HH\Asio\usleep(int) | Awaitable<void> | Wait a given length of time before an async function does more work. |
HH\Asio\later() | Awaitable<void> | Reschedule the work of an async function until some undetermined point in the future. |
HH\Asio\wrap(Awaitable<Tv>) | Awaitable<ResultOrExceptionWrapper<Tv>> | Wrap an Awaitable into an Awaitable of ResultOrExceptionWrapper. |