From 21d0539fcf698af343e1e80516208dcc3c3b9d15 Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Sun, 4 Sep 2016 13:28:30 -0700
Subject: [PATCH] Add append_separated

---
 src/lib.rs    |  7 +------
 src/tokens.rs | 13 +++++++++++++
 2 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index 5913cc4..68d2664 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -43,12 +43,7 @@ macro_rules! quote_each_token {
     };
 
     ($tokens:ident # ( $first:ident ) $sep:tt * $($rest:tt)*) => {
-        for (_i, _v) in $first.iter().enumerate() {
-            if _i > 0 {
-                $tokens.append(stringify!($sep));
-            }
-            _v.to_tokens(&mut $tokens);
-        }
+        $tokens.append_separated($first, stringify!($sep));
         quote_each_token!($tokens $($rest)*);
     };
 
diff --git a/src/tokens.rs b/src/tokens.rs
index 1f972f6..27c891b 100644
--- a/src/tokens.rs
+++ b/src/tokens.rs
@@ -1,3 +1,4 @@
+use super::ToTokens;
 use std::fmt::{self, Display};
 
 #[derive(Debug)]
@@ -12,6 +13,18 @@ impl Tokens {
         self.0.push_str(token);
         self.0.push(' ');
     }
+
+    pub fn append_separated<T, I>(&mut self, iter: I, sep: &str)
+        where T: ToTokens,
+              I: IntoIterator<Item = T>
+    {
+        for (i, token) in iter.into_iter().enumerate() {
+            if i > 0 {
+                self.append(sep);
+            }
+            token.to_tokens(self);
+        }
+    }
 }
 
 impl Default for Tokens {