2 stable releases
1.0.1 | Mar 3, 2023 |
---|---|
1.0.0 | Mar 2, 2023 |
#18 in #removing
42 downloads per month
Used in lingual
16KB
81 lines
remove-async-await
A procedural macro to make an async function blocking by removing async and awaits. Useful for crates with practically identical blocking and async implementations, aside from having to use .await
on some function calls.
Adding as a dependency
It is recommended to point the dependency to 1.0 so you get any bug fixes I have to make:
[dependencies]
remove-async-await = "1.0"
Example
This example assumes you want to keep your async API behind an optional feature called async
.
#[cfg_attr(not(feature = "async"), remove_async_await::remove_async_await)]
async fn get_string() -> String {
"hello world".to_owned()
}
#[cfg_attr(not(feature = "async"), remove_async_await::remove_async_await)]
pub async fn print() {
let string = get_string().await;
println!("{}", string);
}
In this example, if the async
feature is not used, it would expand to this:
fn get_string() -> String {
"hello world".to_owned()
}
pub fn print() {
let string = get_string();
println!("{}", string);
}
However, if the async
feature is used, the code will be unaffected.
You can find more examples in the tests/
directory.
remove_async_await_string
There are 2 macros this library provides:
remove_async_await
: The one you should almost always use. Usessyn
to parse rust code and remove async from functions and await from expressions. Currently, it can only take a function as an input.remove_async_await_string
: You should only use this one ifremove_async_await
doesn't work for your use case. This is the "dumb macro"; it literally just removes all occurrences ofasync
and.await
from the string representation of the input. This means that while it might work with things other than functions, you shouldn't use it because if a function or variable name contains "async" or ".await", your code will break.
Known issues
Here is a list of known issues/limitations that I probably won't fix (PRs are welcome!):
-
Issue:
.await
is not removed when calling a macroWorkarounds:
-
Move the expression using
.await
to a local variable.Example:
#[remove_async_await::remove_async_await)] async fn issue() { println!("{}", get_string().await); // `.await` will not be removed } #[remove_async_await::remove_async_await)] async fn workaround() { let string = get_string().await; // `.await` **will** be removed println!("{}", string); }
-
Use
remove_async_await_string
(read docs for more info, such as potential bad side effects)Example:
#[remove_async_await::remove_async_await)] async fn issue() { println!("{}", get_string().await); // `.await` will not be removed } #[remove_async_await::remove_async_await_string)] async fn workaround() { println!("{}", get_string().await); // `.await` **will** be removed }
-
If you want me to add an issue to this list (or fix the issue), please create a GitHub issue!
Dependencies
~1.5MB
~35K SLoC