Merge #2661

2661: Implement infer await from async function r=flodiebold a=edwin0cheng

This PR is my attempt for trying to add support for infer `.await` expression from an `async` function, by desugaring its return type to `Impl Future<Output=RetType>`.

Note that I don't know it is supposed to desugaring it in that phase, if it is not suitable in current design, just feel free to reject it :)

r=@flodiebold 

Co-authored-by: Edwin Cheng <[email protected]>

1 files changed, 4 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/ast/extensions.rs b/crates/ra_syntax/src/ast/extensions.rs
index a8f625176..baaef3023 100644
--- a/crates/ra_syntax/src/ast/extensions.rs
+++ b/crates/ra_syntax/src/ast/extensions.rs
@@ -221,6 +221,10 @@ impl ast::FnDef {
             .and_then(|it| it.into_token())
             .filter(|it| it.kind() == T![;])
     }
+
+    pub fn is_async(&self) -> bool {
+        self.syntax().children_with_tokens().any(|it| it.kind() == T![async])
+    }
 }
 
 impl ast::LetStmt {