Merge pull request #2864 from topecongiro/issue-2863

Modify the rule for reordering impl items

src/items.rs

@@ -591,23 +591,31 @@ impl<'a> FmtVisitor<'a> {
                 buffer.push((self.buffer.clone(), item.clone()));
                 self.buffer.clear();
             }
-            // type -> const -> macro -> method
+            // type -> existential -> const -> macro -> method
             use ast::ImplItemKind::*;
             fn need_empty_line(a: &ast::ImplItemKind, b: &ast::ImplItemKind) -> bool {
                 match (a, b) {
-                    (Type(..), Type(..)) | (Const(..), Const(..)) => false,
+                    (Type(..), Type(..))
+                    | (Const(..), Const(..))
+                    | (Existential(..), Existential(..)) => false,
                     _ => true,
                 }
             }
 
             buffer.sort_by(|(_, a), (_, b)| match (&a.node, &b.node) {
+                (Type(..), Type(..))
+                | (Const(..), Const(..))
+                | (Macro(..), Macro(..))
+                | (Existential(..), Existential(..)) => a.ident.as_str().cmp(&b.ident.as_str()),
+                (Method(..), Method(..)) => a.span.lo().cmp(&b.span.lo()),
                 (Type(..), _) => Ordering::Less,
                 (_, Type(..)) => Ordering::Greater,
+                (Existential(..), _) => Ordering::Less,
+                (_, Existential(..)) => Ordering::Greater,
                 (Const(..), _) => Ordering::Less,
                 (_, Const(..)) => Ordering::Greater,
                 (Macro(..), _) => Ordering::Less,
                 (_, Macro(..)) => Ordering::Greater,
-                _ => a.span.lo().cmp(&b.span.lo()),
             });
             let mut prev_kind = None;
             for (buf, item) in buffer {

tests/source/issue-2863.rs

@@ -0,0 +1,25 @@
+// rustfmt-reorder_impl_items: true
+
+impl<T> IntoIterator for SafeVec<T> {
+    existential type F: Trait;
+    type IntoIter = self::IntoIter<T>;
+    type Item = T;
+    // comment on foo()
+    fn foo() {println!("hello, world");}
+    type Bar = u32;
+    fn foo1() {println!("hello, world");}
+    type FooBar = u32;
+    fn foo2() {println!("hello, world");}
+    fn foo3() {println!("hello, world");}
+    const SomeConst: i32 = 100;
+    fn foo4() {println!("hello, world");}
+    fn foo5() {println!("hello, world");}
+    // comment on FoooooBar
+    type FoooooBar = u32;
+    fn foo6() {println!("hello, world");}
+    fn foo7() {println!("hello, world");}
+    type BarFoo = u32;
+    existential type E: Trait;
+    const AnotherConst: i32 = 100;
+    fn foo8() {println!("hello, world");}
+}

tests/target/issue-2863.rs

@@ -0,0 +1,54 @@
+// rustfmt-reorder_impl_items: true
+
+impl<T> IntoIterator for SafeVec<T> {
+    type Bar = u32;
+    type BarFoo = u32;
+    type FooBar = u32;
+    // comment on FoooooBar
+    type FoooooBar = u32;
+    type IntoIter = self::IntoIter<T>;
+    type Item = T;
+
+    existential type E: Trait;
+    existential type F: Trait;
+
+    const AnotherConst: i32 = 100;
+    const SomeConst: i32 = 100;
+
+    // comment on foo()
+    fn foo() {
+        println!("hello, world");
+    }
+
+    fn foo1() {
+        println!("hello, world");
+    }
+
+    fn foo2() {
+        println!("hello, world");
+    }
+
+    fn foo3() {
+        println!("hello, world");
+    }
+
+    fn foo4() {
+        println!("hello, world");
+    }
+
+    fn foo5() {
+        println!("hello, world");
+    }
+
+    fn foo6() {
+        println!("hello, world");
+    }
+
+    fn foo7() {
+        println!("hello, world");
+    }
+
+    fn foo8() {
+        println!("hello, world");
+    }
+}