commit 4e5d9660e714b8db860b32ac66aa18e5ad233863
author Yusuke Sasaki <yusuke.sasaki.nuem@gmail.com> Sat Jul 21 02:49:47 2018 +0900
committer David Tolnay <dtolnay@gmail.com> Fri Aug 24 16:37:09 2018 -0400
tree 19f224ef73161edf9eeaf2196766400de8153567
parent f00a3efc7dceef0d57ae01c39a0a39293c80a776

Async closures

src/expr.rs

diff --git a/src/expr.rs b/src/expr.rs
index 3de219c..748f4a5 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -313,6 +313,7 @@
         /// *This type is available if Syn is built with the `"full"` feature.*
         pub Closure(ExprClosure #full {
             pub attrs: Vec<Attribute>,
+            pub asyncness: Option<Token![async]>,
             pub movability: Option<Token![static]>,
             pub capture: Option<Token![move]>,
             pub or1_token: Token![|],
@@ -2101,7 +2102,6 @@
 
     #[cfg(feature = "full")]
     named!(expr_closure(allow_struct: bool) -> Expr, do_parse!(
-        begin: call!(verbatim::grab_cursor) >>
         attrs: many0!(Attribute::parse_outer) >>
         asyncness: option!(keyword!(async)) >>
         movability: option!(cond_reduce!(asyncness.is_none(), keyword!(static))) >>
@@ -2125,27 +2125,17 @@
             |
             map!(ambiguous_expr!(allow_struct), |e| (ReturnType::Default, e))
         ) >>
-        end: call!(verbatim::grab_cursor) >>
-        ({
-            if asyncness.is_some() {
-                // TODO: include asyncness in ExprClosure
-                // https://github.com/dtolnay/syn/issues/396
-                Expr::Verbatim(ExprVerbatim {
-                    tts: verbatim::token_range(begin..end),
-                })
-            } else {
-                Expr::Closure(ExprClosure {
-                    attrs: attrs,
-                    movability: movability,
-                    capture: capture,
-                    or1_token: or1,
-                    inputs: inputs,
-                    or2_token: or2,
-                    output: ret_and_body.0,
-                    body: Box::new(ret_and_body.1),
-                })
-            }
-        })
+        (Expr::Closure(ExprClosure {
+            attrs: attrs,
+            asyncness: asyncness,
+            movability: movability,
+            capture: capture,
+            or1_token: or1,
+            inputs: inputs,
+            or2_token: or2,
+            output: ret_and_body.0,
+            body: Box::new(ret_and_body.1),
+        }))
     ));
 
     #[cfg(feature = "full")]
@@ -3444,6 +3434,7 @@
     impl ToTokens for ExprClosure {
         fn to_tokens(&self, tokens: &mut TokenStream) {
             outer_attrs_to_tokens(&self.attrs, tokens);
+            self.asyncness.to_tokens(tokens);
             self.movability.to_tokens(tokens);
             self.capture.to_tokens(tokens);
             self.or1_token.to_tokens(tokens);

src/gen/fold.rs

diff --git a/src/gen/fold.rs b/src/gen/fold.rs
index f73e64d..450aec9 100644
--- a/src/gen/fold.rs
+++ b/src/gen/fold.rs
@@ -1309,6 +1309,7 @@
 pub fn fold_expr_closure<V: Fold + ?Sized>(_visitor: &mut V, _i: ExprClosure) -> ExprClosure {
     ExprClosure {
         attrs: FoldHelper::lift(_i.attrs, |it| _visitor.fold_attribute(it)),
+        asyncness: (_i.asyncness).map(|it| Token![async](tokens_helper(_visitor, &it.span))),
         movability: (_i.movability).map(|it| Token ! [ static ](tokens_helper(_visitor, &it.span))),
         capture: (_i.capture).map(|it| Token ! [ move ](tokens_helper(_visitor, &it.span))),
         or1_token: Token ! [ | ](tokens_helper(_visitor, &_i.or1_token.spans)),

src/gen/visit.rs

diff --git a/src/gen/visit.rs b/src/gen/visit.rs
index f3015be..f0bf8bf 100644
--- a/src/gen/visit.rs
+++ b/src/gen/visit.rs
@@ -1379,6 +1379,9 @@
     for it in &_i.attrs {
         _visitor.visit_attribute(it)
     }
+    if let Some(ref it) = _i.asyncness {
+        tokens_helper(_visitor, &it.span)
+    };
     if let Some(ref it) = _i.movability {
         tokens_helper(_visitor, &it.span)
     };

src/gen/visit_mut.rs

diff --git a/src/gen/visit_mut.rs b/src/gen/visit_mut.rs
index 6f61765..16e1583 100644
--- a/src/gen/visit_mut.rs
+++ b/src/gen/visit_mut.rs
@@ -1374,6 +1374,9 @@
     for it in &mut _i.attrs {
         _visitor.visit_attribute_mut(it)
     }
+    if let Some(ref mut it) = _i.asyncness {
+        tokens_helper(_visitor, &mut it.span)
+    };
     if let Some(ref mut it) = _i.movability {
         tokens_helper(_visitor, &mut it.span)
     };

tests/test_asyncness.rs

diff --git a/tests/test_async_fn.rs b/tests/test_asyncness.rs
similarity index 63%
rename from tests/test_async_fn.rs
rename to tests/test_asyncness.rs
index b01d6b6..de9abfc 100644
--- a/tests/test_async_fn.rs
+++ b/tests/test_asyncness.rs
@@ -12,7 +12,7 @@
 extern crate syn;
 
 use proc_macro2::Span;
-use syn::{Block, FnDecl, Ident, ItemFn, ReturnType, Visibility};
+use syn::{Block, Expr, ExprBlock, ExprClosure, FnDecl, Ident, ItemFn, ReturnType, Visibility};
 use syn::punctuated::Punctuated;
 
 #[test]
@@ -43,3 +43,28 @@
 
     assert_eq!(expected, syn::parse_str(raw).unwrap());
 }
+
+#[test]
+fn test_async_closure() {
+    let raw = "async || {}";
+
+    let expected = Expr::Closure(ExprClosure {
+        attrs: vec![],
+        movability: None,
+        asyncness: Some(Default::default()),
+        capture: None,
+        or1_token: Default::default(),
+        inputs: Punctuated::new(),
+        or2_token:Default::default(),
+        output: ReturnType::Default,
+        body: Box::new(Expr::Block(ExprBlock {
+            attrs: vec![],
+            block: Block {
+                brace_token: Default::default(),
+                stmts: vec![],
+            }
+        })),
+    });
+
+    assert_eq!(expected, syn::parse_str(raw).unwrap());
+}