Update rules according to PEP 492 + fix await.

progval · progval · commit 7e8eed68e8df · 2018-10-28T14:56:46.000+01:00
ac317700ce7439e38a8b420218d9a5035bba92ed
diff --git a/src/ast.rs b/src/ast.rs
@@ -226,6 +226,7 @@ pub enum Expression {
     SetComp(Box<SetItem>, Vec<ComprehensionChunk>),
     ListComp(Box<SetItem>, Vec<ComprehensionChunk>),
     Generator(Box<SetItem>, Vec<ComprehensionChunk>),
+    Await(Box<Expression>),
 
     Call(Box<Expression>, Vec<Argument>),
     Subscript(Box<Expression>, Vec<Subscript>),
diff --git a/src/expressions.rs b/src/expressions.rs
@@ -212,11 +212,12 @@ named!(power<StrSpan, Box<Expression>>,
 enum Trailer { Call(Vec<Argument>), Subscript(Vec<Subscript>), Attribute(Name) }
 impl<ANS: AreNewlinesSpaces> ExpressionParser<ANS> {
 
-// atom_expr: [AWAIT] atom trailer*
+// atom_expr: ['await'] atom trailer*
 // trailer: '(' [arglist] ')' | '[' subscriptlist ']' | '.' NAME
 // subscriptlist: subscript (',' subscript)* [',']
 named!(atom_expr<StrSpan, Box<Expression>>,
   do_parse!(
+    async: map!(opt!(terminated!(tag!("await"), space_sep!())), |o| o.is_some()) >>
     lhs: call!(Self::atom) >>
     trailers: fold_many0!(
       ws_auto!(alt!(
@@ -231,7 +232,7 @@ named!(atom_expr<StrSpan, Box<Expression>>,
         Trailer::Attribute(name) => Expression::Attribute(acc, name),
       })
     ) >> (
-      trailers
+      if async { Box::new(Expression::Await(trailers)) } else { trailers }
     )
   )
 );
@@ -530,7 +531,8 @@ named_args!(opt_comp_iter(acc: Vec<ComprehensionChunk>) <StrSpan, Vec<Comprehens
   return_error!(map!(opt!(call!(Self::comp_iter, acc.clone())), |r| r.unwrap_or(acc))) // FIXME: do not clone
 );
 
-// comp_for: [ASYNC] 'for' exprlist 'in' or_test [comp_iter]
+// sync_comp_for: 'for' exprlist 'in' or_test [comp_iter]
+// comp_for: ['async'] sync_comp_for
 named!(comp_for<StrSpan, Vec<ComprehensionChunk>>,
   call!(Self::comp_for2, Vec::new())
 );
diff --git a/src/functions.rs b/src/functions.rs
@@ -45,7 +45,7 @@ named_args!(pub decorated(indent: usize) <StrSpan, CompoundStatement>,
  * Function definition
  *********************************************************************/
 
-// async_funcdef: ASYNC funcdef
+// async_funcdef: 'async' funcdef
 // funcdef: 'def' NAME parameters ['->' test] ':' suite
 named_args!(funcdef(indent: usize, decorators: Vec<Decorator>) <StrSpan, CompoundStatement>,
   do_parse!(
diff --git a/src/statements.rs b/src/statements.rs
@@ -338,7 +338,7 @@ named_args!(pub block(indent: usize) <StrSpan, Vec<Statement>>,
         preceded!(
           newline,
           return_error!(
-            ErrorKind::Custom(PyParseError::ExpectedIndent.into()),
+            ::nom::ErrorKind::Custom(PyParseError::ExpectedIndent.into()),
             do_parse!(
               count!(char!(' '), indent) >>
               new_spaces: many1!(char!(' ')) >> ({
@@ -386,15 +386,15 @@ named_args!(compound_stmt(indent: usize) <StrSpan, CompoundStatement>,
     | "def" => return_error!(call!(decorated, indent))
     | "class" => return_error!(call!(decorated, indent))
     | "async" => return_error!(alt!(
-        call!(decorated, indent) // ASYNC funcdef
+        call!(decorated, indent) // 'async' funcdef
       | call!(for_stmt, indent)
       ))
     )
   | call!(decorated, indent)
   )
 );
 
-// async_stmt: ASYNC (funcdef | with_stmt | for_stmt)
+// async_stmt: 'async' (funcdef | with_stmt | for_stmt)
 // taken care of in other parsers
 
 named_args!(else_block(indent: usize) <StrSpan, Option<Vec<Statement>>>,
diff --git a/src/visitors/printer.rs b/src/visitors/printer.rs
@@ -535,6 +535,8 @@ fn format_expr(e: &Expression) -> String {
             format!("[{} {}]", format_setitem(e), space_join(comp.iter().map(format_comp))),
         Expression::Generator(ref e, ref comp) =>
             format!("({} {})", format_setitem(e), space_join(comp.iter().map(format_comp))),
+        Expression::Await(ref e) =>
+            format!("await {}", format_expr(e)),
 
         Expression::Call(ref e, ref args) => {
             match **e {
