From 536c3157955b76297ff667087807ffe463b48018 Mon Sep 17 00:00:00 2001
From: cgswords <cameronswords@gmail.com>
Date: Tue, 19 Jul 2016 13:00:45 -0700
Subject: [PATCH] Introduced `NoDelim` and modified the compiler to support it.

---
 src/librustdoc/html/highlight.rs | 1 +
 src/libsyntax/ext/quote.rs       | 7 ++++---
 src/libsyntax/parse/token.rs     | 2 ++
 src/libsyntax/print/pprust.rs    | 4 ++++
 4 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/librustdoc/html/highlight.rs b/src/librustdoc/html/highlight.rs
index 096e1ecc9ffb6..6cb79d6e8630f 100644
--- a/src/librustdoc/html/highlight.rs
+++ b/src/librustdoc/html/highlight.rs
@@ -233,6 +233,7 @@ impl<'a> Classifier<'a> {
             token::Dot | token::DotDot | token::DotDotDot | token::Comma | token::Semi |
                 token::Colon | token::ModSep | token::LArrow | token::OpenDelim(_) |
                 token::CloseDelim(token::Brace) | token::CloseDelim(token::Paren) |
+                token::CloseDelim(token::NoDelim) |
                 token::Question => Class::None,
             token::Dollar => {
                 if self.lexer.peek().tok.is_ident() {
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index ffc950d76dd27..b70e270df54d2 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -581,9 +581,10 @@ fn mk_binop(cx: &ExtCtxt, sp: Span, bop: token::BinOpToken) -> P<ast::Expr> {
 
 fn mk_delim(cx: &ExtCtxt, sp: Span, delim: token::DelimToken) -> P<ast::Expr> {
     let name = match delim {
-        token::Paren     => "Paren",
-        token::Bracket   => "Bracket",
-        token::Brace     => "Brace",
+        token::Paren   => "Paren",
+        token::Bracket => "Bracket",
+        token::Brace   => "Brace",
+        token::NoDelim => "NoDelim",
     };
     mk_token_path(cx, sp, name)
 }
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index f0a6f8edeec73..6fdc9b714d347 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -48,6 +48,8 @@ pub enum DelimToken {
     Bracket,
     /// A curly brace: `{` or `}`
     Brace,
+    /// An empty delimiter
+    NoDelim,
 }
 
 #[derive(Clone, RustcEncodable, RustcDecodable, PartialEq, Eq, Hash, Debug, Copy)]
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 8866ffc2575cc..a619da84b2d51 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -242,6 +242,8 @@ pub fn token_to_string(tok: &Token) -> String {
         token::CloseDelim(token::Bracket) => "]".to_string(),
         token::OpenDelim(token::Brace) => "{".to_string(),
         token::CloseDelim(token::Brace) => "}".to_string(),
+        token::OpenDelim(token::NoDelim) => " ".to_string(),
+        token::CloseDelim(token::NoDelim) => " ".to_string(),
         token::Pound                => "#".to_string(),
         token::Dollar               => "$".to_string(),
         token::Question             => "?".to_string(),
@@ -1777,12 +1779,14 @@ impl<'a> State<'a> {
                 try!(self.head(""));
                 try!(self.bopen());
             }
+            token::NoDelim => {}
         }
         try!(self.print_tts(&m.node.tts));
         match delim {
             token::Paren => self.pclose(),
             token::Bracket => word(&mut self.s, "]"),
             token::Brace => self.bclose(m.span),
+            token::NoDelim => Ok(()),
         }
     }