Refactor YieldKind so postfix yield must have an expression

Author: eholk

src/chains.rs

@@ -259,7 +259,7 @@ impl ChainItemKind {
                 let span = mk_sp(nested.span.hi(), expr.span.hi());
                 (ChainItemKind::Await, span)
             }
-            ast::ExprKind::Yield(Some(ref nested), ast::YieldKind::Postfix) => {
+            ast::ExprKind::Yield(ast::YieldKind::Postfix(ref nested)) => {
                 let span = mk_sp(nested.span.hi(), expr.span.hi());
                 (ChainItemKind::Yield, span)
             }
@@ -516,7 +516,7 @@ impl Chain {
             ast::ExprKind::Field(ref subexpr, _)
             | ast::ExprKind::Try(ref subexpr)
             | ast::ExprKind::Await(ref subexpr, _)
-            | ast::ExprKind::Yield(Some(ref subexpr), ast::YieldKind::Postfix) => Some(SubExpr {
+            | ast::ExprKind::Yield(ast::YieldKind::Postfix(ref subexpr)) => Some(SubExpr {
                 expr: Self::convert_try(subexpr, context),
                 is_method_call_receiver: false,
             }),

src/expr.rs

@@ -221,7 +221,7 @@ pub(crate) fn format_expr(
                 Ok(format!("break{id_str}"))
             }
         }
-        ast::ExprKind::Yield(ref opt_expr, ast::YieldKind::Prefix) => {
+        ast::ExprKind::Yield(ast::YieldKind::Prefix(ref opt_expr)) => {
             if let Some(ref expr) = *opt_expr {
                 rewrite_unary_prefix(context, "yield ", &**expr, shape)
             } else {
@@ -244,7 +244,7 @@ pub(crate) fn format_expr(
         | ast::ExprKind::Field(..)
         | ast::ExprKind::MethodCall(..)
         | ast::ExprKind::Await(_, _)
-        | ast::ExprKind::Yield(_, ast::YieldKind::Postfix) => rewrite_chain(expr, context, shape),
+        | ast::ExprKind::Yield(ast::YieldKind::Postfix(_)) => rewrite_chain(expr, context, shape),
         ast::ExprKind::MacCall(ref mac) => {
             rewrite_macro(mac, None, context, shape, MacroPosition::Expression).or_else(|_| {
                 wrap_str(

src/utils.rs

@@ -485,7 +485,7 @@ pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr
         | ast::ExprKind::Index(_, ref expr, _)
         | ast::ExprKind::Unary(_, ref expr)
         | ast::ExprKind::Try(ref expr)
-        | ast::ExprKind::Yield(Some(ref expr), YieldKind::Prefix) => {
+        | ast::ExprKind::Yield(YieldKind::Prefix(Some(ref expr))) => {
             is_block_expr(context, expr, repr)
         }
         ast::ExprKind::Closure(ref closure) => is_block_expr(context, &closure.body, repr),
@@ -517,7 +517,7 @@ pub(crate) fn is_block_expr(context: &RewriteContext<'_>, expr: &ast::Expr, repr
         | ast::ExprKind::Tup(..)
         | ast::ExprKind::Use(..)
         | ast::ExprKind::Type(..)
-        | ast::ExprKind::Yield(_, _)
+        | ast::ExprKind::Yield(..)
         | ast::ExprKind::Underscore => false,
     }
 }