Change `fold_tt` and `fold_tts` to take token trees by value (instead of by reference)

8 files changed, 68 insertions, 88 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 68b22c5bdde..657c8447431 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -1152,13 +1152,13 @@ pub enum TokenTree {
     /// A single token
     Token(Span, token::Token),
     /// A delimited sequence of token trees
-    Delimited(Span, Rc<Delimited>),
+    Delimited(Span, Delimited),
 
     // This only makes sense in MBE macros.
 
     /// A kleene-style repetition sequence with a span
     // FIXME(eddyb) #12938 Use DST.
-    Sequence(Span, Rc<SequenceRepetition>),
+    Sequence(Span, SequenceRepetition),
 }
 
 impl TokenTree {
@@ -1207,7 +1207,7 @@ impl TokenTree {
                     Some(*cnt)
                 }).max().unwrap_or(0);
 
-                TokenTree::Delimited(sp, Rc::new(Delimited {
+                TokenTree::Delimited(sp, Delimited {
                     delim: token::Bracket,
                     open_span: sp,
                     tts: vec![TokenTree::Token(sp, token::Ident(token::str_to_ident("doc"))),
@@ -1215,7 +1215,7 @@ impl TokenTree {
                               TokenTree::Token(sp, token::Literal(
                                   token::StrRaw(token::intern(&stripped), num_of_hashes), None))],
                     close_span: sp,
-                }))
+                })
             }
             (&TokenTree::Delimited(_, ref delimed), _) => {
                 if index == 0 {
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 46aa7539b4f..a9809a67ea2 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -236,7 +236,7 @@ fn expand_mac_invoc<T>(mac: ast::Mac, ident: Option<Ident>, attrs: Vec<ast::Attr
                     },
                 });
 
-                let marked_tts = mark_tts(&tts[..], mark);
+                let marked_tts = mark_tts(tts, mark);
                 Some(expandfun.expand(fld.cx, call_site, &marked_tts))
             }
 
@@ -256,7 +256,7 @@ fn expand_mac_invoc<T>(mac: ast::Mac, ident: Option<Ident>, attrs: Vec<ast::Attr
                     }
                 });
 
-                let marked_tts = mark_tts(&tts, mark);
+                let marked_tts = mark_tts(tts, mark);
                 Some(expander.expand(fld.cx, call_site, ident, marked_tts))
             }
 
@@ -1190,7 +1190,7 @@ impl Folder for Marker {
         Spanned {
             node: Mac_ {
                 path: self.fold_path(node.path),
-                tts: self.fold_tts(&node.tts),
+                tts: self.fold_tts(node.tts),
             },
             span: self.new_span(span),
         }
@@ -1205,7 +1205,7 @@ impl Folder for Marker {
 }
 
 // apply a given mark to the given token trees. Used prior to expansion of a macro.
-fn mark_tts(tts: &[TokenTree], m: Mrk) -> Vec<TokenTree> {
+fn mark_tts(tts: Vec<TokenTree>, m: Mrk) -> Vec<TokenTree> {
     noop_fold_tts(tts, &mut Marker{mark:m, expn_id: None})
 }
 
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 871b0d4b1c0..5b509a4fdb2 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -31,7 +31,6 @@ pub mod rt {
     use ext::base::ExtCtxt;
     use parse::{self, token, classify};
     use ptr::P;
-    use std::rc::Rc;
 
     use ast::TokenTree;
 
@@ -214,12 +213,12 @@ pub mod rt {
             if self.node.style == ast::AttrStyle::Inner {
                 r.push(TokenTree::Token(self.span, token::Not));
             }
-            r.push(TokenTree::Delimited(self.span, Rc::new(ast::Delimited {
+            r.push(TokenTree::Delimited(self.span, ast::Delimited {
                 delim: token::Bracket,
                 open_span: self.span,
                 tts: self.node.value.to_tokens(cx),
                 close_span: self.span,
-            })));
+            }));
             r
         }
     }
@@ -234,12 +233,12 @@ pub mod rt {
 
     impl ToTokens for () {
         fn to_tokens(&self, _cx: &ExtCtxt) -> Vec<TokenTree> {
-            vec![TokenTree::Delimited(DUMMY_SP, Rc::new(ast::Delimited {
+            vec![TokenTree::Delimited(DUMMY_SP, ast::Delimited {
                 delim: token::Paren,
                 open_span: DUMMY_SP,
                 tts: vec![],
                 close_span: DUMMY_SP,
-            }))]
+            })]
         }
     }
 
@@ -789,14 +788,9 @@ fn statements_mk_tt(cx: &ExtCtxt, tt: &TokenTree, matcher: bool) -> Vec<ast::Stm
                                                cx.expr_usize(sp, seq.num_captures))];
             let seq_path = vec![id_ext("syntax"), id_ext("ast"), id_ext("SequenceRepetition")];
             let e_seq_struct = cx.expr_struct(sp, cx.path_global(sp, seq_path), fields);
-            let e_rc_new = cx.expr_call_global(sp, vec![id_ext("std"),
-                                                        id_ext("rc"),
-                                                        id_ext("Rc"),
-                                                        id_ext("new")],
-                                                   vec![e_seq_struct]);
             let e_tok = cx.expr_call(sp,
                                      mk_tt_path(cx, sp, "Sequence"),
-                                     vec!(e_sp, e_rc_new));
+                                     vec!(e_sp, e_seq_struct));
             let e_push =
                 cx.expr_method_call(sp,
                                     cx.expr_ident(sp, id_ext("tt")),
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index bbe989b0f40..7365bf3c6b0 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -27,7 +27,6 @@ use util::small_vector::SmallVector;
 use std::cell::RefCell;
 use std::collections::{HashMap};
 use std::collections::hash_map::{Entry};
-use std::rc::Rc;
 
 struct ParserAnyMacro<'a> {
     parser: RefCell<Parser<'a>>,
@@ -246,26 +245,25 @@ pub fn compile<'cx>(cx: &'cx mut ExtCtxt,
     // These spans won't matter, anyways
     let match_lhs_tok = MatchNt(lhs_nm, token::str_to_ident("tt"));
     let match_rhs_tok = MatchNt(rhs_nm, token::str_to_ident("tt"));
-    let argument_gram = vec!(
-        TokenTree::Sequence(DUMMY_SP,
-                   Rc::new(ast::SequenceRepetition {
-                       tts: vec![
-                           TokenTree::Token(DUMMY_SP, match_lhs_tok),
-                           TokenTree::Token(DUMMY_SP, token::FatArrow),
-                           TokenTree::Token(DUMMY_SP, match_rhs_tok)],
-                       separator: Some(token::Semi),
-                       op: ast::KleeneOp::OneOrMore,
-                       num_captures: 2
-                   })),
-        //to phase into semicolon-termination instead of
-        //semicolon-separation
-        TokenTree::Sequence(DUMMY_SP,
-                   Rc::new(ast::SequenceRepetition {
-                       tts: vec![TokenTree::Token(DUMMY_SP, token::Semi)],
-                       separator: None,
-                       op: ast::KleeneOp::ZeroOrMore,
-                       num_captures: 0
-                   })));
+    let argument_gram = vec![
+        TokenTree::Sequence(DUMMY_SP, ast::SequenceRepetition {
+            tts: vec![
+                TokenTree::Token(DUMMY_SP, match_lhs_tok),
+                TokenTree::Token(DUMMY_SP, token::FatArrow),
+                TokenTree::Token(DUMMY_SP, match_rhs_tok)
+            ],
+            separator: Some(token::Semi),
+            op: ast::KleeneOp::OneOrMore,
+            num_captures: 2,
+        }),
+        // to phase into semicolon-termination instead of semicolon-separation
+        TokenTree::Sequence(DUMMY_SP, ast::SequenceRepetition {
+            tts: vec![TokenTree::Token(DUMMY_SP, token::Semi)],
+            separator: None,
+            op: ast::KleeneOp::ZeroOrMore,
+            num_captures: 0,
+        }),
+    ];
 
 
     // Parse the macro_rules! invocation (`none` is for no interpolations):
diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs
index 6b3b5ce9de9..cf9c7e37ce8 100644
--- a/src/libsyntax/ext/tt/transcribe.rs
+++ b/src/libsyntax/ext/tt/transcribe.rs
@@ -79,11 +79,11 @@ pub fn new_tt_reader_with_doc_flag(sp_diag: &Handler,
     let mut r = TtReader {
         sp_diag: sp_diag,
         stack: vec!(TtFrame {
-            forest: TokenTree::Sequence(DUMMY_SP, Rc::new(ast::SequenceRepetition {
+            forest: TokenTree::Sequence(DUMMY_SP, ast::SequenceRepetition {
                 tts: src,
                 // doesn't matter. This merely holds the root unzipping.
                 separator: None, op: ast::KleeneOp::ZeroOrMore, num_captures: 0
-            })),
+            }),
             idx: 0,
             dotdotdoted: false,
             sep: None,
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 45c030d8e1f..b88e10e4822 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -27,8 +27,6 @@ use ptr::P;
 use util::small_vector::SmallVector;
 use util::move_map::MoveMap;
 
-use std::rc::Rc;
-
 pub trait Folder : Sized {
     // Any additions to this trait should happen in form
     // of a call to a public `noop_*` function that only calls
@@ -227,11 +225,11 @@ pub trait Folder : Sized {
         noop_fold_ty_params(tps, self)
     }
 
-    fn fold_tt(&mut self, tt: &TokenTree) -> TokenTree {
+    fn fold_tt(&mut self, tt: TokenTree) -> TokenTree {
         noop_fold_tt(tt, self)
     }
 
-    fn fold_tts(&mut self, tts: &[TokenTree]) -> Vec<TokenTree> {
+    fn fold_tts(&mut self, tts: Vec<TokenTree>) -> Vec<TokenTree> {
         noop_fold_tts(tts, self)
     }
 
@@ -519,7 +517,7 @@ pub fn noop_fold_mac<T: Folder>(Spanned {node, span}: Mac, fld: &mut T) -> Mac {
     Spanned {
         node: Mac_ {
             path: fld.fold_path(node.path),
-            tts: fld.fold_tts(&node.tts),
+            tts: fld.fold_tts(node.tts),
         },
         span: fld.new_span(span)
     }
@@ -546,34 +544,26 @@ pub fn noop_fold_arg<T: Folder>(Arg {id, pat, ty}: Arg, fld: &mut T) -> Arg {
     }
 }
 
-pub fn noop_fold_tt<T: Folder>(tt: &TokenTree, fld: &mut T) -> TokenTree {
-    match *tt {
+pub fn noop_fold_tt<T: Folder>(tt: TokenTree, fld: &mut T) -> TokenTree {
+    match tt {
         TokenTree::Token(span, ref tok) =>
             TokenTree::Token(span, fld.fold_token(tok.clone())),
-        TokenTree::Delimited(span, ref delimed) => {
-            TokenTree::Delimited(span, Rc::new(
-                            Delimited {
-                                delim: delimed.delim,
-                                open_span: delimed.open_span,
-                                tts: fld.fold_tts(&delimed.tts),
-                                close_span: delimed.close_span,
-                            }
-                        ))
-        },
-        TokenTree::Sequence(span, ref seq) =>
-            TokenTree::Sequence(span,
-                       Rc::new(SequenceRepetition {
-                           tts: fld.fold_tts(&seq.tts),
-                           separator: seq.separator.clone().map(|tok| fld.fold_token(tok)),
-                           ..**seq
-                       })),
+        TokenTree::Delimited(span, delimed) => TokenTree::Delimited(span, Delimited {
+            delim: delimed.delim,
+            open_span: delimed.open_span,
+            tts: fld.fold_tts(delimed.tts),
+            close_span: delimed.close_span,
+        }),
+        TokenTree::Sequence(span, seq) => TokenTree::Sequence(span, SequenceRepetition {
+            tts: fld.fold_tts(seq.tts),
+            separator: seq.separator.clone().map(|tok| fld.fold_token(tok)),
+            ..seq
+        }),
     }
 }
 
-pub fn noop_fold_tts<T: Folder>(tts: &[TokenTree], fld: &mut T) -> Vec<TokenTree> {
-    // FIXME: Does this have to take a tts slice?
-    // Could use move_map otherwise...
-    tts.iter().map(|tt| fld.fold_tt(tt)).collect()
+pub fn noop_fold_tts<T: Folder>(tts: Vec<TokenTree>, fld: &mut T) -> Vec<TokenTree> {
+    tts.move_map(|tt| fld.fold_tt(tt))
 }
 
 // apply ident folder if it's an ident, apply other folds to interpolated nodes
@@ -631,7 +621,7 @@ pub fn noop_fold_interpolated<T: Folder>(nt: token::Nonterminal, fld: &mut T)
             token::NtIdent(Box::new(Spanned::<Ident>{node: fld.fold_ident(id.node), ..*id})),
         token::NtMeta(meta_item) => token::NtMeta(fld.fold_meta_item(meta_item)),
         token::NtPath(path) => token::NtPath(Box::new(fld.fold_path(*path))),
-        token::NtTT(tt) => token::NtTT(P(fld.fold_tt(&tt))),
+        token::NtTT(tt) => token::NtTT(tt.map(|tt| fld.fold_tt(tt))),
         token::NtArm(arm) => token::NtArm(fld.fold_arm(arm)),
         token::NtImplItem(arm) =>
             token::NtImplItem(arm.map(|arm| fld.fold_impl_item(arm)
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 2a9bcfd658c..4eb77a52f58 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -660,7 +660,6 @@ pub fn integer_lit(s: &str,
 #[cfg(test)]
 mod tests {
     use super::*;
-    use std::rc::Rc;
     use codemap::{Span, BytePos, Pos, Spanned, NO_EXPANSION};
     use ast::{self, TokenTree, PatKind};
     use abi::Abi;
@@ -759,7 +758,7 @@ mod tests {
                             )
                             if first_delimed.delim == token::Paren
                             && ident.name.as_str() == "a" => {},
-                            _ => panic!("value 3: {:?}", **first_delimed),
+                            _ => panic!("value 3: {:?}", *first_delimed),
                         }
                         let tts = &second_delimed.tts[..];
                         match (tts.len(), tts.get(0), tts.get(1)) {
@@ -770,10 +769,10 @@ mod tests {
                             )
                             if second_delimed.delim == token::Paren
                             && ident.name.as_str() == "a" => {},
-                            _ => panic!("value 4: {:?}", **second_delimed),
+                            _ => panic!("value 4: {:?}", *second_delimed),
                         }
                     },
-                    _ => panic!("value 2: {:?}", **macro_delimed),
+                    _ => panic!("value 2: {:?}", *macro_delimed),
                 }
             },
             _ => panic!("value: {:?}",tts),
@@ -789,7 +788,7 @@ mod tests {
             TokenTree::Token(sp(3, 4), token::Ident(str_to_ident("a"))),
             TokenTree::Delimited(
                 sp(5, 14),
-                Rc::new(ast::Delimited {
+                ast::Delimited {
                     delim: token::DelimToken::Paren,
                     open_span: sp(5, 6),
                     tts: vec![
@@ -798,10 +797,10 @@ mod tests {
                         TokenTree::Token(sp(10, 13), token::Ident(str_to_ident("i32"))),
                     ],
                     close_span: sp(13, 14),
-                })),
+                }),
             TokenTree::Delimited(
                 sp(15, 21),
-                Rc::new(ast::Delimited {
+                ast::Delimited {
                     delim: token::DelimToken::Brace,
                     open_span: sp(15, 16),
                     tts: vec![
@@ -809,7 +808,7 @@ mod tests {
                         TokenTree::Token(sp(18, 19), token::Semi),
                     ],
                     close_span: sp(20, 21),
-                }))
+                })
         ];
 
         assert_eq!(tts, expected);
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 0a6b5781887..d958fc09f88 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -2671,13 +2671,12 @@ impl<'a> Parser<'a> {
                     )?;
                     let (sep, repeat) = self.parse_sep_and_kleene_op()?;
                     let name_num = macro_parser::count_names(&seq);
-                    return Ok(TokenTree::Sequence(mk_sp(sp.lo, seq_span.hi),
-                                      Rc::new(SequenceRepetition {
-                                          tts: seq,
-                                          separator: sep,
-                                          op: repeat,
-                                          num_captures: name_num
-                                      })));
+                    return Ok(TokenTree::Sequence(mk_sp(sp.lo, seq_span.hi), SequenceRepetition {
+                        tts: seq,
+                        separator: sep,
+                        op: repeat,
+                        num_captures: name_num
+                    }));
                 } else if self.token.is_keyword(keywords::Crate) {
                     self.bump();
                     return Ok(TokenTree::Token(sp, SpecialVarNt(SpecialMacroVar::CrateMacroVar)));
@@ -2832,12 +2831,12 @@ impl<'a> Parser<'a> {
                     _ => {}
                 }
 
-                Ok(TokenTree::Delimited(span, Rc::new(Delimited {
+                Ok(TokenTree::Delimited(span, Delimited {
                     delim: delim,
                     open_span: open_span,
                     tts: tts,
                     close_span: close_span,
-                })))
+                }))
             },
             _ => {
                 // invariants: the current token is not a left-delimiter,