From 787043496aaa05be31162a8cdd0686a13da646cc Mon Sep 17 00:00:00 2001
From: Fireassember <ariel.f2002@gmail.com>
Date: Fri, 6 Mar 2020 19:29:30 +0200
Subject: [PATCH] added fmt::Display as a supertrait for AstNode and changed
 generation.

---
 crates/ra_syntax/src/ast.rs     | 2 +-
 xtask/src/codegen/gen_syntax.rs | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 4a70c712f0..26fafb469a 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -30,7 +30,7 @@ pub use self::{
 /// conversion itself has zero runtime cost: ast and syntax nodes have exactly
 /// the same representation: a pointer to the tree root and a pointer to the
 /// node itself.
-pub trait AstNode {
+pub trait AstNode: std::fmt::Display {
     fn can_cast(kind: SyntaxKind) -> bool
     where
         Self: Sized;
diff --git a/xtask/src/codegen/gen_syntax.rs b/xtask/src/codegen/gen_syntax.rs
index db05dcebb0..879f0243ed 100644
--- a/xtask/src/codegen/gen_syntax.rs
+++ b/xtask/src/codegen/gen_syntax.rs
@@ -68,6 +68,12 @@ fn generate_ast(grammar: AstSrc<'_>) -> Result<String> {
                 pub(crate) syntax: SyntaxNode,
             }
 
+            impl std::fmt::Display for #name {
+                fn fmt(..) -> std::fmt::Result {
+                    std::fmt::Display::fmt(self.syntax())
+                }
+            }
+
             impl AstNode for #name {
                 fn can_cast(kind: SyntaxKind) -> bool {
                     match kind {