Reduce the size of `Token` and make it cheaper to clone by refactoring

`Token::Interpolated(Nonterminal)` -> `Token::Interpolated(Rc<Nonterminal>)`.

1 files changed, 9 insertions, 3 deletions

diff --git a/src/libsyntax/tokenstream.rs b/src/libsyntax/tokenstream.rs
index 9e644e59e86..a0dd7b4c521 100644
--- a/src/libsyntax/tokenstream.rs
+++ b/src/libsyntax/tokenstream.rs
@@ -134,8 +134,10 @@ impl TokenTree {
                     AttrStyle::Inner => 3,
                 }
             }
+            TokenTree::Token(_, token::Interpolated(ref nt)) => {
+                if let Nonterminal::NtTT(..) = **nt { 1 } else { 0 }
+            },
             TokenTree::Token(_, token::MatchNt(..)) => 3,
-            TokenTree::Token(_, token::Interpolated(Nonterminal::NtTT(..))) => 1,
             TokenTree::Delimited(_, ref delimed) => delimed.tts.len() + 2,
             TokenTree::Sequence(_, ref seq) => seq.tts.len(),
             TokenTree::Token(..) => 0,
@@ -193,8 +195,12 @@ impl TokenTree {
                          TokenTree::Token(sp, token::Ident(kind))];
                 v[index].clone()
             }
-            (&TokenTree::Token(_, token::Interpolated(Nonterminal::NtTT(ref tt))), _) => {
-                tt.clone().unwrap()
+            (&TokenTree::Token(_, token::Interpolated(ref nt)), _) => {
+                if let Nonterminal::NtTT(ref tt) = **nt {
+                    tt.clone()
+                } else {
+                    panic!("Cannot expand a token tree");
+                }
             }
             (&TokenTree::Sequence(_, ref seq), _) => seq.tts[index].clone(),
             _ => panic!("Cannot expand a token tree"),