Auto merge of #23265 - eddyb:meth-ast-refactor, r=nikomatsakis

The end result is that common fields (id, name, attributes, etc.) are stored in now-structures `ImplItem` and `TraitItem`.
The signature of a method is no longer duplicated between methods with a body (default/impl) and those without, they now share `MethodSig`.

This is also a [breaking-change] because of minor bugfixes and changes to syntax extensions:
* `pub fn` methods in a trait no longer parse - remove the `pub`, it has no meaning anymore
* `MacResult::make_methods` is now `make_impl_items` and the return type has changed accordingly
* `quote_method` is gone, because `P<ast::Method>` doesn't exist and it couldn't represent a full method anyways - could be replaced by `quote_impl_item`/`quote_trait_item` in the future, but I do hope we realize how silly that combinatorial macro expansion is and settle on a single `quote` macro + some type hints - or just no types at all (only token-trees)

r? @nikomatsakis This is necessary (hopefully also sufficient) for associated constants.

14 files changed, 503 insertions, 983 deletions

diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 550ce3bb8c8..657ffcaece9 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -22,7 +22,7 @@ pub use self::Expr_::*;
 pub use self::FloatTy::*;
 pub use self::FunctionRetTy::*;
 pub use self::ForeignItem_::*;
-pub use self::ImplItem::*;
+pub use self::ImplItem_::*;
 pub use self::InlinedItem::*;
 pub use self::IntTy::*;
 pub use self::Item_::*;
@@ -33,7 +33,6 @@ pub use self::LocalSource::*;
 pub use self::Mac_::*;
 pub use self::MacStmtStyle::*;
 pub use self::MetaItem_::*;
-pub use self::Method_::*;
 pub use self::Mutability::*;
 pub use self::Pat_::*;
 pub use self::PathListItem_::*;
@@ -44,7 +43,7 @@ pub use self::Stmt_::*;
 pub use self::StrStyle::*;
 pub use self::StructFieldKind::*;
 pub use self::TokenTree::*;
-pub use self::TraitItem::*;
+pub use self::TraitItem_::*;
 pub use self::Ty_::*;
 pub use self::TyParamBound::*;
 pub use self::UintTy::*;
@@ -1058,20 +1057,15 @@ pub struct TypeField {
     pub span: Span,
 }
 
-/// Represents a required method in a trait declaration,
-/// one without a default implementation
+/// Represents a method's signature in a trait declaration,
+/// or in an implementation.
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub struct TypeMethod {
-    pub ident: Ident,
-    pub attrs: Vec<Attribute>,
+pub struct MethodSig {
     pub unsafety: Unsafety,
     pub abi: Abi,
     pub decl: P<FnDecl>,
     pub generics: Generics,
     pub explicit_self: ExplicitSelf,
-    pub id: NodeId,
-    pub span: Span,
-    pub vis: Visibility,
 }
 
 /// Represents a method declaration in a trait declaration, possibly including
@@ -1079,32 +1073,35 @@ pub struct TypeMethod {
 /// doesn't have an implementation, just a signature) or provided (meaning it
 /// has a default implementation).
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub enum TraitItem {
-    RequiredMethod(TypeMethod),
-    ProvidedMethod(P<Method>),
-    TypeTraitItem(P<AssociatedType>),
-}
-
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub enum ImplItem {
-    MethodImplItem(P<Method>),
-    TypeImplItem(P<Typedef>),
+pub struct TraitItem {
+    pub id: NodeId,
+    pub ident: Ident,
+    pub attrs: Vec<Attribute>,
+    pub node: TraitItem_,
+    pub span: Span,
 }
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub struct AssociatedType {
-    pub attrs: Vec<Attribute>,
-    pub ty_param: TyParam,
+pub enum TraitItem_ {
+    MethodTraitItem(MethodSig, Option<P<Block>>),
+    TypeTraitItem(TyParamBounds, Option<P<Ty>>),
 }
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub struct Typedef {
+pub struct ImplItem {
     pub id: NodeId,
-    pub span: Span,
     pub ident: Ident,
     pub vis: Visibility,
     pub attrs: Vec<Attribute>,
-    pub typ: P<Ty>,
+    pub node: ImplItem_,
+    pub span: Span,
+}
+
+#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+pub enum ImplItem_ {
+    MethodImplItem(MethodSig, P<Block>),
+    TypeImplItem(P<Ty>),
+    MacImplItem(Mac),
 }
 
 #[derive(Clone, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
@@ -1419,29 +1416,6 @@ pub enum ExplicitSelf_ {
 pub type ExplicitSelf = Spanned<ExplicitSelf_>;
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub struct Method {
-    pub attrs: Vec<Attribute>,
-    pub id: NodeId,
-    pub span: Span,
-    pub node: Method_,
-}
-
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
-pub enum Method_ {
-    /// Represents a method declaration
-    MethDecl(Ident,
-             Generics,
-             Abi,
-             ExplicitSelf,
-             Unsafety,
-             P<FnDecl>,
-             P<Block>,
-             Visibility),
-    /// Represents a macro in method position
-    MethMac(Mac),
-}
-
-#[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct Mod {
     /// A span from the first token past `{` to the last token until `}`.
     /// For `mod foo;`, the inner span ranges from the first token
@@ -1659,7 +1633,7 @@ pub enum Item_ {
     ItemTrait(Unsafety,
               Generics,
               TyParamBounds,
-              Vec<TraitItem>),
+              Vec<P<TraitItem>>),
 
     // Default trait implementations
     // `impl Trait for ..`
@@ -1669,7 +1643,7 @@ pub enum Item_ {
              Generics,
              Option<TraitRef>, // (optional) trait this impl implements
              P<Ty>, // self
-             Vec<ImplItem>),
+             Vec<P<ImplItem>>),
     /// A macro invocation (which includes macro definition)
     ItemMac(Mac),
 }
@@ -1726,8 +1700,8 @@ impl ForeignItem_ {
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub enum InlinedItem {
     IIItem(P<Item>),
-    IITraitItem(DefId /* impl id */, TraitItem),
-    IIImplItem(DefId /* impl id */, ImplItem),
+    IITraitItem(DefId /* impl id */, P<TraitItem>),
+    IIImplItem(DefId /* impl id */, P<ImplItem>),
     IIForeign(P<ForeignItem>),
 }
 
diff --git a/src/libsyntax/ast_map/blocks.rs b/src/libsyntax/ast_map/blocks.rs
index 1a537c7a5b8..16a339cdcb5 100644
--- a/src/libsyntax/ast_map/blocks.rs
+++ b/src/libsyntax/ast_map/blocks.rs
@@ -28,7 +28,6 @@ use ast::{Block, FnDecl, NodeId};
 use ast;
 use ast_map::{Node};
 use ast_map;
-use ast_util::PostExpansionMethod;
 use codemap::Span;
 use visit;
 
@@ -65,7 +64,7 @@ impl MaybeFnLike for ast::Item {
 
 impl MaybeFnLike for ast::TraitItem {
     fn is_fn_like(&self) -> bool {
-        match *self { ast::ProvidedMethod(_) => true, _ => false, }
+        match self.node { ast::MethodTraitItem(_, Some(_)) => true, _ => false, }
     }
 }
 
@@ -156,25 +155,25 @@ impl<'a> FnLikeNode<'a> {
 
     pub fn body(self) -> &'a Block {
         self.handle(|i: ItemFnParts<'a>|  &*i.body,
-                    |m: &'a ast::Method|  m.pe_body(),
+                    |_, _, _: &'a ast::MethodSig, body: &'a ast::Block, _|  body,
                     |c: ClosureParts<'a>| c.body)
     }
 
     pub fn decl(self) -> &'a FnDecl {
         self.handle(|i: ItemFnParts<'a>|  &*i.decl,
-                    |m: &'a ast::Method|  m.pe_fn_decl(),
+                    |_, _, sig: &'a ast::MethodSig, _, _|  &sig.decl,
                     |c: ClosureParts<'a>| c.decl)
     }
 
     pub fn span(self) -> Span {
         self.handle(|i: ItemFnParts|     i.span,
-                    |m: &'a ast::Method| m.span,
+                    |_, _, _: &'a ast::MethodSig, _, span| span,
                     |c: ClosureParts|    c.span)
     }
 
     pub fn id(self) -> NodeId {
         self.handle(|i: ItemFnParts|     i.id,
-                    |m: &'a ast::Method| m.id,
+                    |id, _, _: &'a ast::MethodSig, _, _| id,
                     |c: ClosureParts|    c.id)
     }
 
@@ -185,15 +184,15 @@ impl<'a> FnLikeNode<'a> {
         let closure = |_: ClosureParts| {
             visit::FkFnBlock
         };
-        let method = |m: &'a ast::Method| {
-            visit::FkMethod(m.pe_ident(), m.pe_generics(), m)
+        let method = |_, ident, sig: &'a ast::MethodSig, _, _| {
+            visit::FkMethod(ident, sig)
         };
         self.handle(item, method, closure)
     }
 
     fn handle<A, I, M, C>(self, item_fn: I, method: M, closure: C) -> A where
         I: FnOnce(ItemFnParts<'a>) -> A,
-        M: FnOnce(&'a ast::Method) -> A,
+        M: FnOnce(NodeId, ast::Ident, &'a ast::MethodSig, &'a ast::Block, Span) -> A,
         C: FnOnce(ClosureParts<'a>) -> A,
     {
         match self.node {
@@ -205,14 +204,19 @@ impl<'a> FnLikeNode<'a> {
                     }),
                 _ => panic!("item FnLikeNode that is not fn-like"),
             },
-            ast_map::NodeTraitItem(t) => match *t {
-                ast::ProvidedMethod(ref m) => method(&**m),
+            ast_map::NodeTraitItem(ti) => match ti.node {
+                ast::MethodTraitItem(ref sig, Some(ref body)) => {
+                    method(ti.id, ti.ident, sig, body, ti.span)
+                }
                 _ => panic!("trait method FnLikeNode that is not fn-like"),
             },
             ast_map::NodeImplItem(ii) => {
-                match *ii {
-                    ast::MethodImplItem(ref m) => method(&**m),
-                    ast::TypeImplItem(_) => {
+                match ii.node {
+                    ast::MethodImplItem(ref sig, ref body) => {
+                        method(ii.id, ii.ident, sig, body, ii.span)
+                    }
+                    ast::TypeImplItem(_) |
+                    ast::MacImplItem(_) => {
                         panic!("impl method FnLikeNode that is not fn-like")
                     }
                 }
diff --git a/src/libsyntax/ast_map/mod.rs b/src/libsyntax/ast_map/mod.rs
index b96d735d92d..48bb044cb18 100644
--- a/src/libsyntax/ast_map/mod.rs
+++ b/src/libsyntax/ast_map/mod.rs
@@ -19,7 +19,6 @@ use codemap::{DUMMY_SP, Span, Spanned};
 use fold::Folder;
 use parse::token;
 use print::pprust;
-use ptr::P;
 use visit::{self, Visitor};
 
 use arena::TypedArena;
@@ -375,35 +374,8 @@ impl<'ast> Map<'ast> {
                 }
             }
             NodeForeignItem(i) => PathName(i.ident.name),
-            NodeImplItem(ii) => {
-                match *ii {
-                    MethodImplItem(ref m) => {
-                        match m.node {
-                            MethDecl(ident, _, _, _, _, _, _, _) => {
-                                PathName(ident.name)
-                            }
-                            MethMac(_) => {
-                                panic!("no path elem for {:?}", node)
-                            }
-                        }
-                    }
-                    TypeImplItem(ref t) => PathName(t.ident.name),
-                }
-            },
-            NodeTraitItem(tm) => match *tm {
-                RequiredMethod(ref m) => PathName(m.ident.name),
-                ProvidedMethod(ref m) => {
-                    match m.node {
-                        MethDecl(ident, _, _, _, _, _, _, _) => {
-                            PathName(ident.name)
-                        }
-                        MethMac(_) => panic!("no path elem for {:?}", node),
-                    }
-                }
-                TypeTraitItem(ref m) => {
-                    PathName(m.ty_param.ident.name)
-                }
-            },
+            NodeImplItem(ii) => PathName(ii.ident.name),
+            NodeTraitItem(ti) => PathName(ti.ident.name),
             NodeVariant(v) => PathName(v.node.name.name),
             _ => panic!("no path elem for {:?}", node)
         }
@@ -459,21 +431,12 @@ impl<'ast> Map<'ast> {
 
     /// Given a node ID, get a list of of attributes associated with the AST
     /// corresponding to the Node ID
-    pub fn attrs(&self, id: NodeId) -> &[Attribute] {
+    pub fn attrs(&self, id: NodeId) -> &'ast [Attribute] {
         let attrs = match self.find(id) {
             Some(NodeItem(i)) => Some(&i.attrs[..]),
             Some(NodeForeignItem(fi)) => Some(&fi.attrs[..]),
-            Some(NodeTraitItem(ref tm)) => match **tm {
-                RequiredMethod(ref type_m) => Some(&type_m.attrs[..]),
-                ProvidedMethod(ref m) => Some(&m.attrs[..]),
-                TypeTraitItem(ref typ) => Some(&typ.attrs[..]),
-            },
-            Some(NodeImplItem(ref ii)) => {
-                match **ii {
-                    MethodImplItem(ref m) => Some(&m.attrs[..]),
-                    TypeImplItem(ref t) => Some(&t.attrs[..]),
-                }
-            }
+            Some(NodeTraitItem(ref ti)) => Some(&ti.attrs[..]),
+            Some(NodeImplItem(ref ii)) => Some(&ii.attrs[..]),
             Some(NodeVariant(ref v)) => Some(&v.node.attrs[..]),
             // unit/tuple structs take the attributes straight from
             // the struct definition.
@@ -506,19 +469,8 @@ impl<'ast> Map<'ast> {
         let sp = match self.find(id) {
             Some(NodeItem(item)) => item.span,
             Some(NodeForeignItem(foreign_item)) => foreign_item.span,
-            Some(NodeTraitItem(trait_method)) => {
-                match *trait_method {
-                    RequiredMethod(ref type_method) => type_method.span,
-                    ProvidedMethod(ref method) => method.span,
-                    TypeTraitItem(ref typedef) => typedef.ty_param.span,
-                }
-            }
-            Some(NodeImplItem(ref impl_item)) => {
-                match **impl_item {
-                    MethodImplItem(ref method) => method.span,
-                    TypeImplItem(ref typedef) => typedef.span,
-                }
-            }
+            Some(NodeTraitItem(trait_method)) => trait_method.span,
+            Some(NodeImplItem(ref impl_item)) => impl_item.span,
             Some(NodeVariant(variant)) => variant.span,
             Some(NodeExpr(expr)) => expr.span,
             Some(NodeStmt(stmt)) => stmt.span,
@@ -651,31 +603,8 @@ impl<T:Named> Named for Spanned<T> { fn name(&self) -> Name { self.node.name() }
 impl Named for Item { fn name(&self) -> Name { self.ident.name } }
 impl Named for ForeignItem { fn name(&self) -> Name { self.ident.name } }
 impl Named for Variant_ { fn name(&self) -> Name { self.name.name } }
-impl Named for TraitItem {
-    fn name(&self) -> Name {
-        match *self {
-            RequiredMethod(ref tm) => tm.ident.name,
-            ProvidedMethod(ref m) => m.name(),
-            TypeTraitItem(ref at) => at.ty_param.ident.name,
-        }
-    }
-}
-impl Named for ImplItem {
-    fn name(&self) -> Name {
-        match *self {
-            MethodImplItem(ref m) => m.name(),
-            TypeImplItem(ref td) => td.ident.name,
-        }
-    }
-}
-impl Named for Method {
-    fn name(&self) -> Name {
-        match self.node {
-            MethDecl(i, _, _, _, _, _, _, _) => i.name,
-            MethMac(_) => panic!("encountered unexpanded method macro."),
-        }
-    }
-}
+impl Named for TraitItem { fn name(&self) -> Name { self.ident.name } }
+impl Named for ImplItem { fn name(&self) -> Name { self.ident.name } }
 
 pub trait FoldOps {
     fn new_id(&self, id: NodeId) -> NodeId {
@@ -740,15 +669,8 @@ impl<'ast> Visitor<'ast> for NodeCollector<'ast> {
         self.parent = i.id;
         match i.node {
             ItemImpl(_, _, _, _, _, ref impl_items) => {
-                for impl_item in impl_items {
-                    match *impl_item {
-                        MethodImplItem(ref m) => {
-                            self.insert(m.id, NodeImplItem(impl_item));
-                        }
-                        TypeImplItem(ref t) => {
-                            self.insert(t.id, NodeImplItem(impl_item));
-                        }
-                    }
+                for ii in impl_items {
+                    self.insert(ii.id, NodeImplItem(ii));
                 }
             }
             ItemEnum(ref enum_definition, _) => {
@@ -777,18 +699,8 @@ impl<'ast> Visitor<'ast> for NodeCollector<'ast> {
                     }
                 }
 
-                for tm in trait_items {
-                    match *tm {
-                        RequiredMethod(ref m) => {
-                            self.insert(m.id, NodeTraitItem(tm));
-                        }
-                        ProvidedMethod(ref m) => {
-                            self.insert(m.id, NodeTraitItem(tm));
-                        }
-                        TypeTraitItem(ref typ) => {
-                            self.insert(typ.ty_param.id, NodeTraitItem(tm));
-                        }
-                    }
+                for ti in trait_items {
+                    self.insert(ti.id, NodeTraitItem(ti));
                 }
             }
             _ => {}
@@ -797,6 +709,20 @@ impl<'ast> Visitor<'ast> for NodeCollector<'ast> {
         self.parent = parent;
     }
 
+    fn visit_trait_item(&mut self, ti: &'ast TraitItem) {
+        let parent = self.parent;
+        self.parent = ti.id;
+        visit::walk_trait_item(self, ti);
+        self.parent = parent;
+    }
+
+    fn visit_impl_item(&mut self, ii: &'ast ImplItem) {
+        let parent = self.parent;
+        self.parent = ii.id;
+        visit::walk_impl_item(self, ii);
+        self.parent = parent;
+    }
+
     fn visit_pat(&mut self, pat: &'ast Pat) {
         self.insert(pat.id, match pat.node {
             // Note: this is at least *potentially* a pattern...
@@ -816,29 +742,10 @@ impl<'ast> Visitor<'ast> for NodeCollector<'ast> {
         visit::walk_stmt(self, stmt);
     }
 
-    fn visit_ty_method(&mut self, m: &'ast TypeMethod) {
-        let parent = self.parent;
-        self.parent = m.id;
-        self.visit_fn_decl(&*m.decl);
-        visit::walk_ty_method(self, m);
-        self.parent = parent;
-    }
-
     fn visit_fn(&mut self, fk: visit::FnKind<'ast>, fd: &'ast FnDecl,
-                b: &'ast Block, s: Span, id: NodeId) {
-        match fk {
-            visit::FkMethod(..) => {
-                let parent = self.parent;
-                self.parent = id;
-                self.visit_fn_decl(fd);
-                visit::walk_fn(self, fk, fd, b, s);
-                self.parent = parent;
-            }
-            _ => {
-                self.visit_fn_decl(fd);
-                visit::walk_fn(self, fk, fd, b, s);
-            }
-        }
+                b: &'ast Block, s: Span, _: NodeId) {
+        self.visit_fn_decl(fd);
+        visit::walk_fn(self, fk, fd, b, s);
     }
 
     fn visit_ty(&mut self, ty: &'ast Ty) {
@@ -920,33 +827,14 @@ pub fn map_decoded_item<'ast, F: FoldOps>(map: &Map<'ast>,
     let mut fld = IdAndSpanUpdater { fold_ops: fold_ops };
     let ii = match ii {
         IIItem(i) => IIItem(fld.fold_item(i).expect_one("expected one item")),
-        IITraitItem(d, ti) => match ti {
-            ProvidedMethod(m) => {
-                IITraitItem(fld.fold_ops.new_def_id(d),
-                            ProvidedMethod(fld.fold_method(m)
-                                              .expect_one("expected one method")))
-            }
-            RequiredMethod(ty_m) => {
-                IITraitItem(fld.fold_ops.new_def_id(d),
-                            RequiredMethod(fld.fold_type_method(ty_m)))
-            }
-            TypeTraitItem(at) => {
-                IITraitItem(
-                    fld.fold_ops.new_def_id(d),
-                    TypeTraitItem(P(fld.fold_associated_type((*at).clone()))))
-            }
-        },
-        IIImplItem(d, m) => match m {
-            MethodImplItem(m) => {
-                IIImplItem(fld.fold_ops.new_def_id(d),
-                           MethodImplItem(fld.fold_method(m)
-                                             .expect_one("expected one method")))
-            }
-            TypeImplItem(t) => {
-                IIImplItem(fld.fold_ops.new_def_id(d),
-                           TypeImplItem(P(fld.fold_typedef((*t).clone()))))
-            }
-        },
+        IITraitItem(d, ti) => {
+            IITraitItem(fld.fold_ops.new_def_id(d),
+                        fld.fold_trait_item(ti).expect_one("expected one trait item"))
+        }
+        IIImplItem(d, ii) => {
+            IIImplItem(fld.fold_ops.new_def_id(d),
+                       fld.fold_impl_item(ii).expect_one("expected one impl item"))
+        }
         IIForeign(i) => IIForeign(fld.fold_foreign_item(i))
     };
 
@@ -968,25 +856,14 @@ pub fn map_decoded_item<'ast, F: FoldOps>(map: &Map<'ast>,
     // add it to the table now. Likewise with foreign items.
     match ii_parent.ii {
         IIItem(_) => {}
-        IITraitItem(_, ref trait_item) => {
-            let trait_item_id = match *trait_item {
-                ProvidedMethod(ref m) => m.id,
-                RequiredMethod(ref m) => m.id,
-                TypeTraitItem(ref ty) => ty.ty_param.id,
-            };
-
-            collector.insert(trait_item_id, NodeTraitItem(trait_item));
+        IITraitItem(_, ref ti) => {
+            collector.insert(ti.id, NodeTraitItem(ti));
         }
-        IIImplItem(_, ref impl_item) => {
-            let impl_item_id = match *impl_item {
-                MethodImplItem(ref m) => m.id,
-                TypeImplItem(ref ti) => ti.id,
-            };
-
-            collector.insert(impl_item_id, NodeImplItem(impl_item));
+        IIImplItem(_, ref ii) => {
+            collector.insert(ii.id, NodeImplItem(ii));
         }
         IIForeign(ref i) => {
-            collector.insert(i.id, NodeForeignItem(&**i));
+            collector.insert(i.id, NodeForeignItem(i));
         }
     }
     *map.map.borrow_mut() = collector.map;
@@ -1002,8 +879,8 @@ impl<'a> NodePrinter for pprust::State<'a> {
         match *node {
             NodeItem(a)        => self.print_item(&*a),
             NodeForeignItem(a) => self.print_foreign_item(&*a),
-            NodeTraitItem(a)   => self.print_trait_method(&*a),
-            NodeImplItem(a)    => self.print_impl_item(&*a),
+            NodeTraitItem(a)   => self.print_trait_item(a),
+            NodeImplItem(a)    => self.print_impl_item(a),
             NodeVariant(a)     => self.print_variant(&*a),
             NodeExpr(a)        => self.print_expr(&*a),
             NodeStmt(a)        => self.print_stmt(&*a),
@@ -1050,44 +927,38 @@ fn node_id_to_string(map: &Map, id: NodeId, include_id: bool) -> String {
             let path_str = map.path_to_str_with_ident(id, item.ident);
             format!("foreign item {}{}", path_str, id_str)
         }
-        Some(NodeImplItem(ref ii)) => {
-            match **ii {
-                MethodImplItem(ref m) => {
-                    match m.node {
-                        MethDecl(ident, _, _, _, _, _, _, _) =>
-                            format!("method {} in {}{}",
-                                    token::get_ident(ident),
-                                    map.path_to_string(id), id_str),
-                        MethMac(ref mac) =>
-                            format!("method macro {}{}",
-                                    pprust::mac_to_string(mac), id_str)
-                    }
-                }
-                TypeImplItem(ref t) => {
-                    format!("typedef {} in {}{}",
-                            token::get_ident(t.ident),
-                            map.path_to_string(id),
-                            id_str)
-                }
-            }
-        }
-        Some(NodeTraitItem(ref tm)) => {
-            match **tm {
-                RequiredMethod(_) | ProvidedMethod(_) => {
-                    let m = ast_util::trait_item_to_ty_method(&**tm);
+        Some(NodeImplItem(ii)) => {
+            match ii.node {
+                MethodImplItem(..) => {
                     format!("method {} in {}{}",
-                            token::get_ident(m.ident),
-                            map.path_to_string(id),
-                            id_str)
+                            token::get_ident(ii.ident),
+                            map.path_to_string(id), id_str)
                 }
-                TypeTraitItem(ref t) => {
-                    format!("type item {} in {}{}",
-                            token::get_ident(t.ty_param.ident),
+                TypeImplItem(_) => {
+                    format!("assoc type {} in {}{}",
+                            token::get_ident(ii.ident),
                             map.path_to_string(id),
                             id_str)
                 }
+                MacImplItem(ref mac) => {
+                    format!("method macro {}{}",
+                            pprust::mac_to_string(mac), id_str)
+                }
             }
         }
+        Some(NodeTraitItem(ti)) => {
+            let kind = match ti.node {
+                MethodTraitItem(..) => "trait method",
+                TypeTraitItem(..) => "assoc type",
+//                 ConstTraitItem(..) => "assoc constant"
+            };
+
+            format!("{} {} in {}{}",
+                    kind,
+                    token::get_ident(ti.ident),
+                    map.path_to_string(id),
+                    id_str)
+        }
         Some(NodeVariant(ref variant)) => {
             format!("variant {} in {}{}",
                     token::get_ident(variant.node.name),
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index 26d7562cdb2..cec824e79ff 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use abi::Abi;
 use ast::*;
 use ast;
 use ast_util;
@@ -268,62 +267,6 @@ pub fn impl_pretty_name(trait_ref: &Option<TraitRef>, ty: Option<&Ty>) -> Ident
     token::gensym_ident(&pretty[..])
 }
 
-pub fn trait_method_to_ty_method(method: &Method) -> TypeMethod {
-    match method.node {
-        MethDecl(ident,
-                 ref generics,
-                 abi,
-                 ref explicit_self,
-                 unsafety,
-                 ref decl,
-                 _,
-                 vis) => {
-            TypeMethod {
-                ident: ident,
-                attrs: method.attrs.clone(),
-                unsafety: unsafety,
-                decl: (*decl).clone(),
-                generics: generics.clone(),
-                explicit_self: (*explicit_self).clone(),
-                id: method.id,
-                span: method.span,
-                vis: vis,
-                abi: abi,
-            }
-        },
-        MethMac(_) => panic!("expected non-macro method declaration")
-    }
-}
-
-/// extract a TypeMethod from a TraitItem. if the TraitItem is
-/// a default, pull out the useful fields to make a TypeMethod
-//
-// NB: to be used only after expansion is complete, and macros are gone.
-pub fn trait_item_to_ty_method(method: &TraitItem) -> TypeMethod {
-    match *method {
-        RequiredMethod(ref m) => (*m).clone(),
-        ProvidedMethod(ref m) => trait_method_to_ty_method(&**m),
-        TypeTraitItem(_) => {
-            panic!("trait_method_to_ty_method(): expected method but found \
-                   typedef")
-        }
-    }
-}
-
-pub fn split_trait_methods(trait_methods: &[TraitItem])
-                           -> (Vec<TypeMethod>, Vec<P<Method>> ) {
-    let mut reqd = Vec::new();
-    let mut provd = Vec::new();
-    for trt_method in trait_methods {
-        match *trt_method {
-            RequiredMethod(ref tm) => reqd.push((*tm).clone()),
-            ProvidedMethod(ref m) => provd.push((*m).clone()),
-            TypeTraitItem(_) => {}
-        }
-    };
-    (reqd, provd)
-}
-
 pub fn struct_field_visibility(field: ast::StructField) -> Visibility {
     match field.node.kind {
         ast::NamedField(_, v) | ast::UnnamedField(v) => v
@@ -513,10 +456,12 @@ impl<'a, 'v, O: IdVisitingOperation> Visitor<'v> for IdVisitor<'a, O> {
         self.operation.visit_id(node_id);
 
         match function_kind {
-            visit::FkItemFn(_, generics, _, _) |
-            visit::FkMethod(_, generics, _) => {
+            visit::FkItemFn(_, generics, _, _) => {
                 self.visit_generics_helper(generics)
             }
+            visit::FkMethod(_, sig) => {
+                self.visit_generics_helper(&sig.generics)
+            }
             visit::FkFnBlock => {}
         }
 
@@ -552,13 +497,14 @@ impl<'a, 'v, O: IdVisitingOperation> Visitor<'v> for IdVisitor<'a, O> {
         visit::walk_struct_def(self, struct_def);
     }
 
-    fn visit_trait_item(&mut self, tm: &ast::TraitItem) {
-        match *tm {
-            ast::RequiredMethod(ref m) => self.operation.visit_id(m.id),
-            ast::ProvidedMethod(ref m) => self.operation.visit_id(m.id),
-            ast::TypeTraitItem(ref typ) => self.operation.visit_id(typ.ty_param.id),
-        }
-        visit::walk_trait_item(self, tm);
+    fn visit_trait_item(&mut self, ti: &ast::TraitItem) {
+        self.operation.visit_id(ti.id);
+        visit::walk_trait_item(self, ti);
+    }
+
+    fn visit_impl_item(&mut self, ii: &ast::ImplItem) {
+        self.operation.visit_id(ii.id);
+        visit::walk_impl_item(self, ii);
     }
 
     fn visit_lifetime_ref(&mut self, lifetime: &Lifetime) {
@@ -701,52 +647,6 @@ pub fn lit_is_str(lit: &Lit) -> bool {
     }
 }
 
-/// Macro invocations are guaranteed not to occur after expansion is complete.
-/// Extracting fields of a method requires a dynamic check to make sure that it's
-/// not a macro invocation. This check is guaranteed to succeed, assuming
-/// that the invocations are indeed gone.
-pub trait PostExpansionMethod {
-    fn pe_ident(&self) -> ast::Ident;
-    fn pe_generics<'a>(&'a self) -> &'a ast::Generics;
-    fn pe_abi(&self) -> Abi;
-    fn pe_explicit_self<'a>(&'a self) -> &'a ast::ExplicitSelf;
-    fn pe_unsafety(&self) -> ast::Unsafety;
-    fn pe_fn_decl<'a>(&'a self) -> &'a ast::FnDecl;
-    fn pe_body<'a>(&'a self) -> &'a ast::Block;
-    fn pe_vis(&self) -> ast::Visibility;
-}
-
-macro_rules! mf_method{
-    ($meth_name:ident, $field_ty:ty, $field_pat:pat, $result:expr) => {
-        fn $meth_name<'a>(&'a self) -> $field_ty {
-            match self.node {
-                $field_pat => $result,
-                MethMac(_) => {
-                    panic!("expected an AST without macro invocations");
-                }
-            }
-        }
-    }
-}
-
-
-impl PostExpansionMethod for Method {
-    mf_method! { pe_ident,ast::Ident,MethDecl(ident,_,_,_,_,_,_,_),ident }
-    mf_method! {
-        pe_generics,&'a ast::Generics,
-        MethDecl(_,ref generics,_,_,_,_,_,_),generics
-    }
-    mf_method! { pe_abi,Abi,MethDecl(_,_,abi,_,_,_,_,_),abi }
-    mf_method! {
-        pe_explicit_self,&'a ast::ExplicitSelf,
-        MethDecl(_,_,_,ref explicit_self,_,_,_,_),explicit_self
-    }
-    mf_method! { pe_unsafety,ast::Unsafety,MethDecl(_,_,_,_,unsafety,_,_,_),unsafety }
-    mf_method! { pe_fn_decl,&'a ast::FnDecl,MethDecl(_,_,_,_,_,ref decl,_,_),&**decl }
-    mf_method! { pe_body,&'a ast::Block,MethDecl(_,_,_,_,_,_,ref body,_),&**body }
-    mf_method! { pe_vis,ast::Visibility,MethDecl(_,_,_,_,_,_,_,vis),vis }
-}
-
 #[cfg(test)]
 mod test {
     use ast::*;
diff --git a/src/libsyntax/config.rs b/src/libsyntax/config.rs
index dfe3477bddc..489a7721d7b 100644
--- a/src/libsyntax/config.rs
+++ b/src/libsyntax/config.rs
@@ -118,13 +118,13 @@ fn fold_item_underscore<F>(cx: &mut Context<F>, item: ast::Item_) -> ast::Item_
     let item = match item {
         ast::ItemImpl(u, o, a, b, c, impl_items) => {
             let impl_items = impl_items.into_iter()
-                                       .filter(|ii| impl_item_in_cfg(cx, ii))
+                                       .filter(|ii| (cx.in_cfg)(&ii.attrs))
                                        .collect();
             ast::ItemImpl(u, o, a, b, c, impl_items)
         }
         ast::ItemTrait(u, a, b, methods) => {
             let methods = methods.into_iter()
-                                 .filter(|m| trait_method_in_cfg(cx, m))
+                                 .filter(|ti| (cx.in_cfg)(&ti.attrs))
                                  .collect();
             ast::ItemTrait(u, a, b, methods)
         }
@@ -246,25 +246,6 @@ fn foreign_item_in_cfg<F>(cx: &mut Context<F>, item: &ast::ForeignItem) -> bool
     return (cx.in_cfg)(&item.attrs);
 }
 
-fn trait_method_in_cfg<F>(cx: &mut Context<F>, meth: &ast::TraitItem) -> bool where
-    F: FnMut(&[ast::Attribute]) -> bool
-{
-    match *meth {
-        ast::RequiredMethod(ref meth) => (cx.in_cfg)(&meth.attrs),
-        ast::ProvidedMethod(ref meth) => (cx.in_cfg)(&meth.attrs),
-        ast::TypeTraitItem(ref typ) => (cx.in_cfg)(&typ.attrs),
-    }
-}
-
-fn impl_item_in_cfg<F>(cx: &mut Context<F>, impl_item: &ast::ImplItem) -> bool where
-    F: FnMut(&[ast::Attribute]) -> bool
-{
-    match *impl_item {
-        ast::MethodImplItem(ref meth) => (cx.in_cfg)(&meth.attrs),
-        ast::TypeImplItem(ref typ) => (cx.in_cfg)(&typ.attrs),
-    }
-}
-
 // Determine if an item should be translated in the current crate
 // configuration based on the item's attributes
 fn in_cfg(diagnostic: &SpanHandler, cfg: &[P<ast::MetaItem>], attrs: &[ast::Attribute]) -> bool {
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 8aeafe419da..35449bde0b2 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -77,51 +77,31 @@ impl<F> ItemModifier for F
 #[derive(Debug,Clone)]
 pub enum Annotatable {
     Item(P<ast::Item>),
-    TraitItem(ast::TraitItem),
-    ImplItem(ast::ImplItem),
+    TraitItem(P<ast::TraitItem>),
+    ImplItem(P<ast::ImplItem>),
 }
 
 impl Annotatable {
     pub fn attrs(&self) -> &[ast::Attribute] {
         match *self {
             Annotatable::Item(ref i) => &i.attrs,
-            Annotatable::TraitItem(ref i) => match *i {
-                ast::TraitItem::RequiredMethod(ref tm) => &tm.attrs,
-                ast::TraitItem::ProvidedMethod(ref m) => &m.attrs,
-                ast::TraitItem::TypeTraitItem(ref at) => &at.attrs,
-            },
-            Annotatable::ImplItem(ref i) => match *i {
-                ast::ImplItem::MethodImplItem(ref m) => &m.attrs,
-                ast::ImplItem::TypeImplItem(ref t) => &t.attrs,
-            }
+            Annotatable::TraitItem(ref ti) => &ti.attrs,
+            Annotatable::ImplItem(ref ii) => &ii.attrs,
         }
     }
 
     pub fn fold_attrs(self, attrs: Vec<ast::Attribute>) -> Annotatable {
         match self {
-            Annotatable::Item(i) => Annotatable::Item(P(ast::Item {
+            Annotatable::Item(i) => Annotatable::Item(i.map(|i| ast::Item {
                 attrs: attrs,
-                ..(*i).clone()
+                ..i
+            })),
+            Annotatable::TraitItem(i) => Annotatable::TraitItem(i.map(|ti| {
+                ast::TraitItem { attrs: attrs, ..ti }
+            })),
+            Annotatable::ImplItem(i) => Annotatable::ImplItem(i.map(|ii| {
+                ast::ImplItem { attrs: attrs, ..ii }
             })),
-            Annotatable::TraitItem(i) => match i {
-                ast::TraitItem::RequiredMethod(tm) => Annotatable::TraitItem(
-                    ast::TraitItem::RequiredMethod(
-                        ast::TypeMethod { attrs: attrs, ..tm })),
-                ast::TraitItem::ProvidedMethod(m) => Annotatable::TraitItem(
-                    ast::TraitItem::ProvidedMethod(P(
-                        ast::Method { attrs: attrs, ..(*m).clone() }))),
-                ast::TraitItem::TypeTraitItem(at) => Annotatable::TraitItem(
-                    ast::TraitItem::TypeTraitItem(P(
-                        ast::AssociatedType { attrs: attrs, ..(*at).clone() }))),
-            },
-            Annotatable::ImplItem(i) => match i {
-                ast::ImplItem::MethodImplItem(m) => Annotatable::ImplItem(
-                    ast::ImplItem::MethodImplItem(P(
-                        ast::Method { attrs: attrs, ..(*m).clone() }))),
-                ast::ImplItem::TypeImplItem(t) => Annotatable::ImplItem(
-                    ast::ImplItem::TypeImplItem(P(
-                        ast::Typedef { attrs: attrs, ..(*t).clone() }))),
-            }
         }
     }
 
@@ -132,14 +112,14 @@ impl Annotatable {
         }
     }
 
-    pub fn expect_trait_item(self) -> ast::TraitItem {
+    pub fn expect_trait_item(self) -> P<ast::TraitItem> {
         match self {
             Annotatable::TraitItem(i) => i,
             _ => panic!("expected Item")
         }
     }
 
-    pub fn expect_impl_item(self) -> ast::ImplItem {
+    pub fn expect_impl_item(self) -> P<ast::ImplItem> {
         match self {
             Annotatable::ImplItem(i) => i,
             _ => panic!("expected Item")
@@ -248,8 +228,8 @@ pub trait MacResult {
         None
     }
 
-    /// Create zero or more methods.
-    fn make_methods(self: Box<Self>) -> Option<SmallVector<P<ast::Method>>> {
+    /// Create zero or more impl items.
+    fn make_impl_items(self: Box<Self>) -> Option<SmallVector<P<ast::ImplItem>>> {
         None
     }
 
@@ -295,7 +275,7 @@ make_MacEager! {
     expr: P<ast::Expr>,
     pat: P<ast::Pat>,
     items: SmallVector<P<ast::Item>>,
-    methods: SmallVector<P<ast::Method>>,
+    impl_items: SmallVector<P<ast::ImplItem>>,
     stmt: P<ast::Stmt>,
 }
 
@@ -308,8 +288,8 @@ impl MacResult for MacEager {
         self.items
     }
 
-    fn make_methods(self: Box<Self>) -> Option<SmallVector<P<ast::Method>>> {
-        self.methods
+    fn make_impl_items(self: Box<Self>) -> Option<SmallVector<P<ast::ImplItem>>> {
+        self.impl_items
     }
 
     fn make_stmt(self: Box<Self>) -> Option<P<ast::Stmt>> {
@@ -397,7 +377,7 @@ impl MacResult for DummyResult {
             Some(SmallVector::zero())
         }
     }
-    fn make_methods(self: Box<DummyResult>) -> Option<SmallVector<P<ast::Method>>> {
+    fn make_impl_items(self: Box<DummyResult>) -> Option<SmallVector<P<ast::ImplItem>>> {
         if self.expr_only {
             None
         } else {
@@ -505,9 +485,6 @@ fn initial_syntax_expander_table<'feat>(ecfg: &expand::ExpansionConfig<'feat>)
         syntax_expanders.insert(intern("quote_ty"),
                            builtin_normal_expander(
                                 ext::quote::expand_quote_ty));
-        syntax_expanders.insert(intern("quote_method"),
-                           builtin_normal_expander(
-                                ext::quote::expand_quote_method));
         syntax_expanders.insert(intern("quote_item"),
                            builtin_normal_expander(
                                 ext::quote::expand_quote_item));
diff --git a/src/libsyntax/ext/deriving/generic/mod.rs b/src/libsyntax/ext/deriving/generic/mod.rs
index 9cd965a8138..58b6d96607d 100644
--- a/src/libsyntax/ext/deriving/generic/mod.rs
+++ b/src/libsyntax/ext/deriving/generic/mod.rs
@@ -386,22 +386,22 @@ impl<'a> TraitDef<'a> {
                            cx: &mut ExtCtxt,
                            type_ident: Ident,
                            generics: &Generics,
-                           methods: Vec<P<ast::Method>>) -> P<ast::Item> {
+                           methods: Vec<P<ast::ImplItem>>) -> P<ast::Item> {
         let trait_path = self.path.to_path(cx, self.span, type_ident, generics);
 
-        // Transform associated types from `deriving::ty::Ty` into `ast::Typedef`
+        // Transform associated types from `deriving::ty::Ty` into `ast::ImplItem`
         let associated_types = self.associated_types.iter().map(|&(ident, ref type_def)| {
-            P(ast::Typedef {
+            P(ast::ImplItem {
                 id: ast::DUMMY_NODE_ID,
                 span: self.span,
                 ident: ident,
                 vis: ast::Inherited,
                 attrs: Vec::new(),
-                typ: type_def.to_ty(cx,
+                node: ast::TypeImplItem(type_def.to_ty(cx,
                     self.span,
                     type_ident,
                     generics
-                ),
+                )),
             })
         });
 
@@ -510,14 +510,7 @@ impl<'a> TraitDef<'a> {
                           trait_generics,
                           opt_trait_ref,
                           self_type,
-                          methods.into_iter()
-                                 .map(|method| {
-                                     ast::MethodImplItem(method)
-                                 }).chain(
-                                     associated_types.map(|type_| {
-                                         ast::TypeImplItem(type_)
-                                     })
-                                 ).collect()))
+                          methods.into_iter().chain(associated_types).collect()))
     }
 
     fn expand_struct_def(&self,
@@ -702,7 +695,7 @@ impl<'a> MethodDef<'a> {
                      abi: Abi,
                      explicit_self: ast::ExplicitSelf,
                      arg_types: Vec<(Ident, P<ast::Ty>)> ,
-                     body: P<Expr>) -> P<ast::Method> {
+                     body: P<Expr>) -> P<ast::ImplItem> {
         // create the generics that aren't for Self
         let fn_generics = self.generics.to_generics(cx, trait_.span, type_ident, generics);
 
@@ -725,18 +718,19 @@ impl<'a> MethodDef<'a> {
         let body_block = cx.block_expr(body);
 
         // Create the method.
-        P(ast::Method {
-            attrs: self.attributes.clone(),
+        P(ast::ImplItem {
             id: ast::DUMMY_NODE_ID,
+            attrs: self.attributes.clone(),
             span: trait_.span,
-            node: ast::MethDecl(method_ident,
-                                fn_generics,
-                                abi,
-                                explicit_self,
-                                ast::Unsafety::Normal,
-                                fn_decl,
-                                body_block,
-                                ast::Inherited)
+            vis: ast::Inherited,
+            ident: method_ident,
+            node: ast::MethodImplItem(ast::MethodSig {
+                generics: fn_generics,
+                abi: abi,
+                explicit_self: explicit_self,
+                unsafety: ast::Unsafety::Normal,
+                decl: fn_decl
+            }, body_block)
         })
     }
 
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 6883395933e..ee2cf9017bb 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -1174,29 +1174,26 @@ fn expand_annotatable(a: Annotatable,
                 noop_fold_item(it, fld).into_iter().map(|i| Annotatable::Item(i)).collect()
             }
         },
-        Annotatable::TraitItem(it) => match it {
-            ast::TraitItem::ProvidedMethod(m) => {
-                expand_method(m, fld).into_iter().map(|m|
-                    Annotatable::TraitItem(ast::TraitItem::ProvidedMethod(m))).collect()
-            }
-            ast::TraitItem::RequiredMethod(m) => {
-                SmallVector::one(Annotatable::TraitItem(
-                    ast::TraitItem::RequiredMethod(fld.fold_type_method(m))))
-            }
-            ast::TraitItem::TypeTraitItem(t) => {
-                SmallVector::one(Annotatable::TraitItem(
-                    ast::TraitItem::TypeTraitItem(P(fld.fold_associated_type((*t).clone())))))
-            }
-        },
-        Annotatable::ImplItem(it) => match it {
-            ast::ImplItem::MethodImplItem(m) => {
-                expand_method(m, fld).into_iter().map(|m|
-                    Annotatable::ImplItem(ast::ImplItem::MethodImplItem(m))).collect()
-            }
-            ast::ImplItem::TypeImplItem(t) => {
-                SmallVector::one(Annotatable::ImplItem(
-                    ast::ImplItem::TypeImplItem(P(fld.fold_typedef((*t).clone())))))
-            }
+
+        Annotatable::TraitItem(it) => match it.node {
+            ast::MethodTraitItem(_, Some(_)) => SmallVector::one(it.map(|ti| ast::TraitItem {
+                id: ti.id,
+                ident: ti.ident,
+                attrs: ti.attrs,
+                node: match ti.node  {
+                    ast::MethodTraitItem(sig, Some(body)) => {
+                        let (sig, body) = expand_and_rename_method(sig, body, fld);
+                        ast::MethodTraitItem(sig, Some(body))
+                    }
+                    _ => unreachable!()
+                },
+                span: fld.new_span(ti.span)
+            })),
+            _ => fold::noop_fold_trait_item(it, fld)
+        }.into_iter().map(Annotatable::TraitItem).collect(),
+
+        Annotatable::ImplItem(ii) => {
+            expand_impl_item(ii, fld).into_iter().map(Annotatable::ImplItem).collect()
         }
     };
 
@@ -1204,21 +1201,6 @@ fn expand_annotatable(a: Annotatable,
     new_items
 }
 
-fn expand_trait_item(i: ast::TraitItem,
-                     fld: &mut MacroExpander)
-                     -> SmallVector<ast::TraitItem> {
-    expand_annotatable(Annotatable::TraitItem(i), fld)
-        .into_iter().map(|i| i.expect_trait_item()).collect()
-
-}
-
-fn expand_impl_item(i: ast::ImplItem,
-                    fld: &mut MacroExpander)
-                    -> SmallVector<ast::ImplItem> {
-    expand_annotatable(Annotatable::ImplItem(i), fld)
-        .into_iter().map(|i| i.expect_impl_item()).collect()
-}
-
 // partition the attributes into ItemModifiers and others
 fn modifiers(attrs: &Vec<ast::Attribute>,
              fld: &MacroExpander)
@@ -1292,54 +1274,48 @@ fn expand_item_multi_modifier(mut it: Annotatable,
     expand_item_multi_modifier(it, fld)
 }
 
-// expand a method
-fn expand_method(m: P<ast::Method>, fld: &mut MacroExpander) -> SmallVector<P<ast::Method>> {
-    m.and_then(|m| match m.node {
-        ast::MethDecl(ident,
-                      generics,
-                      abi,
-                      explicit_self,
-                      fn_style,
-                      decl,
-                      body,
-                      vis) => {
-            let id = fld.new_id(m.id);
-            let (rewritten_fn_decl, rewritten_body)
-                = expand_and_rename_fn_decl_and_block(decl, body, fld);
-            SmallVector::one(P(ast::Method {
-                    attrs: fold::fold_attrs(m.attrs, fld),
-                    id: id,
-                    span: fld.new_span(m.span),
-                    node: ast::MethDecl(fld.fold_ident(ident),
-                                        noop_fold_generics(generics, fld),
-                                        abi,
-                                        fld.fold_explicit_self(explicit_self),
-                                        fn_style,
-                                        rewritten_fn_decl,
-                                        rewritten_body,
-                                        vis)
-                }))
-        },
-        ast::MethMac(mac) => {
-            let maybe_new_methods =
-                expand_mac_invoc(mac, m.span,
-                                 |r| r.make_methods(),
-                                 |meths, mark| meths.move_map(|m| mark_method(m, mark)),
+fn expand_impl_item(ii: P<ast::ImplItem>, fld: &mut MacroExpander)
+                 -> SmallVector<P<ast::ImplItem>> {
+    match ii.node {
+        ast::MethodImplItem(..) => SmallVector::one(ii.map(|ii| ast::ImplItem {
+            id: ii.id,
+            ident: ii.ident,
+            attrs: ii.attrs,
+            vis: ii.vis,
+            node: match ii.node  {
+                ast::MethodImplItem(sig, body) => {
+                    let (sig, body) = expand_and_rename_method(sig, body, fld);
+                    ast::MethodImplItem(sig, body)
+                }
+                _ => unreachable!()
+            },
+            span: fld.new_span(ii.span)
+        })),
+        ast::MacImplItem(_) => {
+            let (span, mac) = ii.and_then(|ii| match ii.node {
+                ast::MacImplItem(mac) => (ii.span, mac),
+                _ => unreachable!()
+            });
+            let maybe_new_items =
+                expand_mac_invoc(mac, span,
+                                 |r| r.make_impl_items(),
+                                 |meths, mark| meths.move_map(|m| mark_impl_item(m, mark)),
                                  fld);
 
-            match maybe_new_methods {
-                Some(methods) => {
+            match maybe_new_items {
+                Some(impl_items) => {
                     // expand again if necessary
-                    let new_methods = methods.into_iter()
-                                             .flat_map(|m| fld.fold_method(m).into_iter())
-                                             .collect();
+                    let new_items = impl_items.into_iter().flat_map(|ii| {
+                        expand_impl_item(ii, fld).into_iter()
+                    }).collect();
                     fld.cx.bt_pop();
-                    new_methods
+                    new_items
                 }
                 None => SmallVector::zero()
             }
         }
-    })
+        _ => fold::noop_fold_impl_item(ii, fld)
+    }
 }
 
 /// Given a fn_decl and a block and a MacroExpander, expand the fn_decl, then use the
@@ -1347,7 +1323,7 @@ fn expand_method(m: P<ast::Method>, fld: &mut MacroExpander) -> SmallVector<P<as
 /// the block, returning both the new FnDecl and the new Block.
 fn expand_and_rename_fn_decl_and_block(fn_decl: P<ast::FnDecl>, block: P<ast::Block>,
                                        fld: &mut MacroExpander)
-    -> (P<ast::FnDecl>, P<ast::Block>) {
+                                       -> (P<ast::FnDecl>, P<ast::Block>) {
     let expanded_decl = fld.fold_fn_decl(fn_decl);
     let idents = fn_decl_arg_bindings(&*expanded_decl);
     let renames =
@@ -1361,6 +1337,20 @@ fn expand_and_rename_fn_decl_and_block(fn_decl: P<ast::FnDecl>, block: P<ast::Bl
     (rewritten_fn_decl,rewritten_body)
 }
 
+fn expand_and_rename_method(sig: ast::MethodSig, body: P<ast::Block>,
+                            fld: &mut MacroExpander)
+                            -> (ast::MethodSig, P<ast::Block>) {
+    let (rewritten_fn_decl, rewritten_body)
+        = expand_and_rename_fn_decl_and_block(sig.decl, body, fld);
+    (ast::MethodSig {
+        generics: fld.fold_generics(sig.generics),
+        abi: sig.abi,
+        explicit_self: fld.fold_explicit_self(sig.explicit_self),
+        unsafety: sig.unsafety,
+        decl: rewritten_fn_decl
+    }, rewritten_body)
+}
+
 /// A tree-folder that performs macro expansion
 pub struct MacroExpander<'a, 'b:'a> {
     pub cx: &'a mut ExtCtxt<'b>,
@@ -1410,16 +1400,14 @@ impl<'a, 'b> Folder for MacroExpander<'a, 'b> {
         expand_arm(arm, self)
     }
 
-    fn fold_trait_item(&mut self, i: ast::TraitItem) -> SmallVector<ast::TraitItem> {
-        expand_trait_item(i, self)
-    }
-
-    fn fold_impl_item(&mut self, i: ast::ImplItem) -> SmallVector<ast::ImplItem> {
-        expand_impl_item(i, self)
+    fn fold_trait_item(&mut self, i: P<ast::TraitItem>) -> SmallVector<P<ast::TraitItem>> {
+        expand_annotatable(Annotatable::TraitItem(i), self)
+            .into_iter().map(|i| i.expect_trait_item()).collect()
     }
 
-    fn fold_method(&mut self, method: P<ast::Method>) -> SmallVector<P<ast::Method>> {
-        expand_method(method, self)
+    fn fold_impl_item(&mut self, i: P<ast::ImplItem>) -> SmallVector<P<ast::ImplItem>> {
+        expand_annotatable(Annotatable::ImplItem(i), self)
+            .into_iter().map(|i| i.expect_impl_item()).collect()
     }
 
     fn fold_ty(&mut self, t: P<ast::Ty>) -> P<ast::Ty> {
@@ -1565,9 +1553,9 @@ fn mark_item(expr: P<ast::Item>, m: Mrk) -> P<ast::Item> {
 }
 
 // apply a given mark to the given item. Used following the expansion of a macro.
-fn mark_method(expr: P<ast::Method>, m: Mrk) -> P<ast::Method> {
-    Marker{mark:m}.fold_method(expr)
-        .expect_one("marking an item didn't return exactly one method")
+fn mark_impl_item(ii: P<ast::ImplItem>, m: Mrk) -> P<ast::ImplItem> {
+    Marker{mark:m}.fold_impl_item(ii)
+        .expect_one("marking an impl item didn't return exactly one impl item")
 }
 
 /// Check that there are no macro invocations left in the AST:
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 737648cd90c..48c045ee4f9 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -176,7 +176,6 @@ pub mod rt {
     impl_to_source! { ast::Arg, arg_to_string }
     impl_to_source! { Generics, generics_to_string }
     impl_to_source! { P<ast::Item>, item_to_string }
-    impl_to_source! { P<ast::Method>, method_to_string }
     impl_to_source! { P<ast::Stmt>, stmt_to_string }
     impl_to_source! { P<ast::Expr>, expr_to_string }
     impl_to_source! { P<ast::Pat>, pat_to_string }
@@ -311,7 +310,6 @@ pub mod rt {
     impl_to_tokens! { P<ast::Item> }
     impl_to_tokens! { P<ast::Pat> }
     impl_to_tokens! { ast::Arm }
-    impl_to_tokens! { P<ast::Method> }
     impl_to_tokens_lifetime! { &'a [P<ast::Item>] }
     impl_to_tokens! { ast::Ty }
     impl_to_tokens_lifetime! { &'a [ast::Ty] }
@@ -446,15 +444,6 @@ pub fn expand_quote_ty(cx: &mut ExtCtxt,
     base::MacEager::expr(expanded)
 }
 
-pub fn expand_quote_method(cx: &mut ExtCtxt,
-                           sp: Span,
-                           tts: &[ast::TokenTree])
-                           -> Box<base::MacResult+'static> {
-    let expanded = expand_parse_call(cx, sp, "parse_method_with_outer_attributes",
-                                     vec!(), tts);
-    base::MacEager::expr(expanded)
-}
-
 pub fn expand_quote_stmt(cx: &mut ExtCtxt,
                          sp: Span,
                          tts: &[ast::TokenTree])
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 644c6cd7e28..7575d4b5ecd 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -71,7 +71,7 @@ impl<'a> MacResult for ParserAnyMacro<'a> {
         loop {
             let mut parser = self.parser.borrow_mut();
             // so... do outer attributes attached to the macro invocation
-            // just disappear? This question applies to make_methods, as
+            // just disappear? This question applies to make_impl_items, as
             // well.
             match parser.parse_item_with_outer_attributes() {
                 Some(item) => ret.push(item),
@@ -82,15 +82,14 @@ impl<'a> MacResult for ParserAnyMacro<'a> {
         Some(ret)
     }
 
-    fn make_methods(self: Box<ParserAnyMacro<'a>>) -> Option<SmallVector<P<ast::Method>>> {
+    fn make_impl_items(self: Box<ParserAnyMacro<'a>>)
+                       -> Option<SmallVector<P<ast::ImplItem>>> {
         let mut ret = SmallVector::zero();
         loop {
             let mut parser = self.parser.borrow_mut();
             match parser.token {
                 token::Eof => break,
-                _ => {
-                    ret.push(parser.parse_method_with_outer_attributes());
-                }
+                _ => ret.push(parser.parse_impl_item_with_outer_attributes())
             }
         }
         self.ensure_complete_parse(false);
diff --git a/src/libsyntax/fold.rs b/src/libsyntax/fold.rs
index 959e3bdb314..105a61d0857 100644
--- a/src/libsyntax/fold.rs
+++ b/src/libsyntax/fold.rs
@@ -98,11 +98,11 @@ pub trait Folder : Sized {
         noop_fold_item_underscore(i, self)
     }
 
-    fn fold_trait_item(&mut self, i: TraitItem) -> SmallVector<TraitItem> {
+    fn fold_trait_item(&mut self, i: P<TraitItem>) -> SmallVector<P<TraitItem>> {
         noop_fold_trait_item(i, self)
     }
 
-    fn fold_impl_item(&mut self, i: ImplItem) -> SmallVector<ImplItem> {
+    fn fold_impl_item(&mut self, i: P<ImplItem>) -> SmallVector<P<ImplItem>> {
         noop_fold_impl_item(i, self)
     }
 
@@ -110,14 +110,6 @@ pub trait Folder : Sized {
         noop_fold_fn_decl(d, self)
     }
 
-    fn fold_type_method(&mut self, m: TypeMethod) -> TypeMethod {
-        noop_fold_type_method(m, self)
-    }
-
-    fn fold_method(&mut self, m: P<Method>) -> SmallVector<P<Method>> {
-        noop_fold_method(m, self)
-    }
-
     fn fold_block(&mut self, b: P<Block>) -> P<Block> {
         noop_fold_block(b, self)
     }
@@ -315,15 +307,6 @@ pub trait Folder : Sized {
         noop_fold_where_predicate(where_predicate, self)
     }
 
-    fn fold_typedef(&mut self, typedef: Typedef) -> Typedef {
-        noop_fold_typedef(typedef, self)
-    }
-
-    fn fold_associated_type(&mut self, associated_type: AssociatedType)
-                            -> AssociatedType {
-        noop_fold_associated_type(associated_type, self)
-    }
-
     fn new_id(&mut self, i: NodeId) -> NodeId {
         i
     }
@@ -829,41 +812,6 @@ pub fn noop_fold_where_predicate<T: Folder>(
     }
 }
 
-pub fn noop_fold_typedef<T>(t: Typedef, folder: &mut T)
-                            -> Typedef
-                            where T: Folder {
-    let new_id = folder.new_id(t.id);
-    let new_span = folder.new_span(t.span);
-    let new_attrs = t.attrs.iter().flat_map(|attr| {
-        folder.fold_attribute((*attr).clone()).into_iter()
-    }).collect();
-    let new_ident = folder.fold_ident(t.ident);
-    let new_type = folder.fold_ty(t.typ);
-    ast::Typedef {
-        ident: new_ident,
-        typ: new_type,
-        id: new_id,
-        span: new_span,
-        vis: t.vis,
-        attrs: new_attrs,
-    }
-}
-
-pub fn noop_fold_associated_type<T>(at: AssociatedType, folder: &mut T)
-                                    -> AssociatedType
-                                    where T: Folder
-{
-    let new_attrs = at.attrs
-                      .iter()
-                      .flat_map(|attr| folder.fold_attribute((*attr).clone()).into_iter())
-                      .collect();
-    let new_param = folder.fold_ty_param(at.ty_param);
-    ast::AssociatedType {
-        attrs: new_attrs,
-        ty_param: new_param,
-    }
-}
-
 pub fn noop_fold_struct_def<T: Folder>(struct_def: P<StructDef>, fld: &mut T) -> P<StructDef> {
     struct_def.map(|StructDef { fields, ctor_id }| StructDef {
         fields: fields.move_map(|f| fld.fold_struct_field(f)),
@@ -1018,61 +966,43 @@ pub fn noop_fold_item_underscore<T: Folder>(i: Item_, folder: &mut T) -> Item_ {
     }
 }
 
-pub fn noop_fold_trait_item<T: Folder>(i: TraitItem, folder: &mut T) -> SmallVector<TraitItem> {
-    match i {
-        RequiredMethod(m) => {
-                SmallVector::one(RequiredMethod(
-                        folder.fold_type_method(m)))
-        }
-        ProvidedMethod(method) => {
-            folder.fold_method(method).into_iter()
-                .map(|m| ProvidedMethod(m)).collect()
-        }
-        TypeTraitItem(at) => {
-            SmallVector::one(TypeTraitItem(P(
-                        folder.fold_associated_type(
-                            (*at).clone()))))
-        }
-    }
-}
-
-pub fn noop_fold_impl_item<T: Folder>(i: ImplItem, folder: &mut T) -> SmallVector<ImplItem> {
-    match i {
-        MethodImplItem(ref x) => {
-            folder.fold_method((*x).clone()).into_iter().map(|m| MethodImplItem(m)).collect()
-        }
-        TypeImplItem(ref t) => {
-            SmallVector::one(TypeImplItem(
-                    P(folder.fold_typedef((**t).clone()))))
-        }
-    }
+pub fn noop_fold_trait_item<T: Folder>(i: P<TraitItem>, folder: &mut T)
+                                       -> SmallVector<P<TraitItem>> {
+    SmallVector::one(i.map(|TraitItem {id, ident, attrs, node, span}| TraitItem {
+        id: folder.new_id(id),
+        ident: folder.fold_ident(ident),
+        attrs: fold_attrs(attrs, folder),
+        node: match node {
+            MethodTraitItem(sig, body) => {
+                MethodTraitItem(noop_fold_method_sig(sig, folder),
+                                body.map(|x| folder.fold_block(x)))
+            }
+            TypeTraitItem(bounds, default) => {
+                TypeTraitItem(folder.fold_bounds(bounds),
+                              default.map(|x| folder.fold_ty(x)))
+            }
+        },
+        span: folder.new_span(span)
+    }))
 }
 
-pub fn noop_fold_type_method<T: Folder>(m: TypeMethod, fld: &mut T) -> TypeMethod {
-    let TypeMethod {
-        id,
-        ident,
-        attrs,
-        unsafety,
-        abi,
-        decl,
-        generics,
-        explicit_self,
-        vis,
-        span
-    } = m;
-    TypeMethod {
-        id: fld.new_id(id),
-        ident: fld.fold_ident(ident),
-        attrs: fold_attrs(attrs, fld),
-        unsafety: unsafety,
-        abi: abi,
-        decl: fld.fold_fn_decl(decl),
-        generics: fld.fold_generics(generics),
-        explicit_self: fld.fold_explicit_self(explicit_self),
+pub fn noop_fold_impl_item<T: Folder>(i: P<ImplItem>, folder: &mut T)
+                                      -> SmallVector<P<ImplItem>> {
+    SmallVector::one(i.map(|ImplItem {id, ident, attrs, node, vis, span}| ImplItem {
+        id: folder.new_id(id),
+        ident: folder.fold_ident(ident),
+        attrs: fold_attrs(attrs, folder),
         vis: vis,
-        span: fld.new_span(span)
-    }
+        node: match node  {
+            MethodImplItem(sig, body) => {
+                MethodImplItem(noop_fold_method_sig(sig, folder),
+                               folder.fold_block(body))
+            }
+            TypeImplItem(ty) => TypeImplItem(folder.fold_ty(ty)),
+            MacImplItem(mac) => MacImplItem(folder.fold_mac(mac))
+        },
+        span: folder.new_span(span)
+    }))
 }
 
 pub fn noop_fold_mod<T: Folder>(Mod {inner, items}: Mod, folder: &mut T) -> Mod {
@@ -1171,34 +1101,14 @@ pub fn noop_fold_foreign_item<T: Folder>(ni: P<ForeignItem>, folder: &mut T) ->
     })
 }
 
-// Default fold over a method.
-// Invariant: produces exactly one method.
-pub fn noop_fold_method<T: Folder>(m: P<Method>, folder: &mut T) -> SmallVector<P<Method>> {
-    SmallVector::one(m.map(|Method {id, attrs, node, span}| Method {
-        id: folder.new_id(id),
-        attrs: fold_attrs(attrs, folder),
-        node: match node {
-            MethDecl(ident,
-                     generics,
-                     abi,
-                     explicit_self,
-                     unsafety,
-                     decl,
-                     body,
-                     vis) => {
-                MethDecl(folder.fold_ident(ident),
-                         folder.fold_generics(generics),
-                         abi,
-                         folder.fold_explicit_self(explicit_self),
-                         unsafety,
-                         folder.fold_fn_decl(decl),
-                         folder.fold_block(body),
-                         vis)
-            },
-            MethMac(mac) => MethMac(folder.fold_mac(mac)),
-        },
-        span: folder.new_span(span)
-    }))
+pub fn noop_fold_method_sig<T: Folder>(sig: MethodSig, folder: &mut T) -> MethodSig {
+    MethodSig {
+        generics: folder.fold_generics(sig.generics),
+        abi: sig.abi,
+        explicit_self: folder.fold_explicit_self(sig.explicit_self),
+        unsafety: sig.unsafety,
+        decl: folder.fold_fn_decl(sig.decl)
+    }
 }
 
 pub fn noop_fold_pat<T: Folder>(p: P<Pat>, folder: &mut T) -> P<Pat> {
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index ea413ac0dc8..39c43ff1e75 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -11,9 +11,9 @@
 pub use self::PathParsingMode::*;
 
 use abi;
-use ast::{AssociatedType, BareFnTy};
+use ast::{BareFnTy};
 use ast::{RegionTyParamBound, TraitTyParamBound, TraitBoundModifier};
-use ast::{ProvidedMethod, Public, Unsafety};
+use ast::{Public, Unsafety};
 use ast::{Mod, BiAdd, Arg, Arm, Attribute, BindByRef, BindByValue};
 use ast::{BiBitAnd, BiBitOr, BiBitXor, BiRem, BiLt, BiGt, Block};
 use ast::{BlockCheckMode, CaptureByRef, CaptureByValue, CaptureClause};
@@ -38,12 +38,11 @@ use ast::{LitBool, LitChar, LitByte, LitBinary};
 use ast::{LitStr, LitInt, Local, LocalLet};
 use ast::{MacStmtWithBraces, MacStmtWithSemicolon, MacStmtWithoutBraces};
 use ast::{MutImmutable, MutMutable, Mac_, MacInvocTT, MatchSource};
-use ast::{Method, MutTy, BiMul, Mutability};
+use ast::{MutTy, BiMul, Mutability};
 use ast::{MethodImplItem, NamedField, UnNeg, NoReturn, NodeId, UnNot};
 use ast::{Pat, PatEnum, PatIdent, PatLit, PatRange, PatRegion, PatStruct};
 use ast::{PatTup, PatBox, PatWild, PatWildMulti, PatWildSingle};
-use ast::{PolyTraitRef};
-use ast::{QSelf, RequiredMethod};
+use ast::{PolyTraitRef, QSelf};
 use ast::{Return, BiShl, BiShr, Stmt, StmtDecl};
 use ast::{StmtExpr, StmtSemi, StmtMac, StructDef, StructField};
 use ast::{StructVariantKind, BiSub, StrStyle};
@@ -51,11 +50,10 @@ use ast::{SelfExplicit, SelfRegion, SelfStatic, SelfValue};
 use ast::{Delimited, SequenceRepetition, TokenTree, TraitItem, TraitRef};
 use ast::{TtDelimited, TtSequence, TtToken};
 use ast::{TupleVariantKind, Ty, Ty_, TypeBinding};
-use ast::{TyFixedLengthVec, TyBareFn};
-use ast::{TyTypeof, TyInfer, TypeMethod};
+use ast::{TyFixedLengthVec, TyBareFn, TyTypeof, TyInfer};
 use ast::{TyParam, TyParamBound, TyParen, TyPath, TyPolyTraitRef, TyPtr};
 use ast::{TyRptr, TyTup, TyU32, TyVec, UnUniq};
-use ast::{TypeImplItem, TypeTraitItem, Typedef,};
+use ast::{TypeImplItem, TypeTraitItem};
 use ast::{UnnamedField, UnsafeBlock};
 use ast::{ViewPath, ViewPathGlob, ViewPathList, ViewPathSimple};
 use ast::{Visibility, WhereClause};
@@ -1244,52 +1242,53 @@ impl<'a> Parser<'a> {
 
     /// Parses `type Foo;` in a trait declaration only. The `type` keyword has
     /// already been parsed.
-    fn parse_associated_type(&mut self, attrs: Vec<Attribute>)
-                             -> AssociatedType
-    {
-        let ty_param = self.parse_ty_param();
+    fn parse_assoc_ty_in_trait(&mut self, attrs: Vec<Attribute>)
+                               -> P<TraitItem> {
+        let TyParam {id, ident, bounds, default, span} = self.parse_ty_param();
         self.expect(&token::Semi);
-        AssociatedType {
+        P(TraitItem {
+            id: id,
+            ident: ident,
             attrs: attrs,
-            ty_param: ty_param,
-        }
+            node: TypeTraitItem(bounds, default),
+            span: span,
+        })
     }
 
     /// Parses `type Foo = TYPE;` in an implementation declaration only. The
     /// `type` keyword has already been parsed.
-    fn parse_typedef(&mut self, attrs: Vec<Attribute>, vis: Visibility)
-                     -> Typedef {
+    fn parse_assoc_ty_in_impl(&mut self, attrs: Vec<Attribute>, vis: Visibility)
+                              -> P<ImplItem> {
         let lo = self.span.lo;
         let ident = self.parse_ident();
         self.expect(&token::Eq);
         let typ = self.parse_ty_sum();
         let hi = self.span.hi;
         self.expect(&token::Semi);
-        Typedef {
+        P(ImplItem {
             id: ast::DUMMY_NODE_ID,
             span: mk_sp(lo, hi),
             ident: ident,
             vis: vis,
             attrs: attrs,
-            typ: typ,
-        }
+            node: TypeImplItem(typ),
+        })
     }
 
     /// Parse the items in a trait declaration
-    pub fn parse_trait_items(&mut self) -> Vec<TraitItem> {
+    pub fn parse_trait_items(&mut self) -> Vec<P<TraitItem>> {
         self.parse_unspanned_seq(
             &token::OpenDelim(token::Brace),
             &token::CloseDelim(token::Brace),
             seq_sep_none(),
             |p| {
-            let attrs = p.parse_outer_attributes();
+            let mut attrs = p.parse_outer_attributes();
 
             if p.eat_keyword(keywords::Type) {
-                TypeTraitItem(P(p.parse_associated_type(attrs)))
+                p.parse_assoc_ty_in_trait(attrs)
             } else {
                 let lo = p.span.lo;
 
-                let vis = p.parse_visibility();
                 let style = p.parse_unsafety();
                 let abi = if p.eat_keyword(keywords::Extern) {
                     p.parse_opt_abi().unwrap_or(abi::C)
@@ -1309,44 +1308,27 @@ impl<'a> Parser<'a> {
                 });
 
                 p.parse_where_clause(&mut generics);
+                let sig = ast::MethodSig {
+                    unsafety: style,
+                    decl: d,
+                    generics: generics,
+                    abi: abi,
+                    explicit_self: explicit_self,
+                };
 
                 let hi = p.last_span.hi;
-                match p.token {
+                let body = match p.token {
                   token::Semi => {
                     p.bump();
                     debug!("parse_trait_methods(): parsing required method");
-                    RequiredMethod(TypeMethod {
-                        ident: ident,
-                        attrs: attrs,
-                        unsafety: style,
-                        decl: d,
-                        generics: generics,
-                        abi: abi,
-                        explicit_self: explicit_self,
-                        id: ast::DUMMY_NODE_ID,
-                        span: mk_sp(lo, hi),
-                        vis: vis,
-                    })
+                    None
                   }
                   token::OpenDelim(token::Brace) => {
                     debug!("parse_trait_methods(): parsing provided method");
                     let (inner_attrs, body) =
                         p.parse_inner_attrs_and_block();
-                    let mut attrs = attrs;
                     attrs.push_all(&inner_attrs[..]);
-                    ProvidedMethod(P(ast::Method {
-                        attrs: attrs,
-                        id: ast::DUMMY_NODE_ID,
-                        span: mk_sp(lo, hi),
-                        node: ast::MethDecl(ident,
-                                            generics,
-                                            abi,
-                                            explicit_self,
-                                            style,
-                                            d,
-                                            body,
-                                            vis)
-                    }))
+                    Some(body)
                   }
 
                   _ => {
@@ -1354,7 +1336,15 @@ impl<'a> Parser<'a> {
                       p.fatal(&format!("expected `;` or `{{`, found `{}`",
                                        token_str)[..])
                   }
-                }
+                };
+
+                P(TraitItem {
+                    id: ast::DUMMY_NODE_ID,
+                    ident: ident,
+                    attrs: attrs,
+                    node: ast::MethodTraitItem(sig, body),
+                    span: mk_sp(lo, hi),
+                })
             }
         })
     }
@@ -4635,11 +4625,15 @@ impl<'a> Parser<'a> {
         (ident, ItemFn(decl, unsafety, abi, generics, body), Some(inner_attrs))
     }
 
-    /// Parse a method in a trait impl
-    pub fn parse_method_with_outer_attributes(&mut self) -> P<Method> {
+    /// Parse an impl item.
+    pub fn parse_impl_item_with_outer_attributes(&mut self) -> P<ImplItem> {
         let attrs = self.parse_outer_attributes();
-        let visa = self.parse_visibility();
-        self.parse_method(attrs, visa)
+        let vis = self.parse_visibility();
+        if self.eat_keyword(keywords::Type) {
+            self.parse_assoc_ty_in_impl(attrs, vis)
+        } else {
+            self.parse_method(attrs, vis)
+        }
     }
 
     fn complain_if_pub_macro(&mut self, visa: Visibility, span: Span) {
@@ -4656,12 +4650,12 @@ impl<'a> Parser<'a> {
     /// Parse a method in a trait impl, starting with `attrs` attributes.
     pub fn parse_method(&mut self,
                         attrs: Vec<Attribute>,
-                        visa: Visibility)
-                        -> P<Method> {
+                        vis: Visibility)
+                        -> P<ImplItem> {
         let lo = self.span.lo;
 
         // code copied from parse_macro_use_or_failure... abstraction!
-        let (method_, hi, new_attrs) = {
+        let (method_, hi, new_attrs, ident) = {
             if !self.token.is_any_keyword()
                 && self.look_ahead(1, |t| *t == token::Not)
                 && (self.look_ahead(2, |t| *t == token::OpenDelim(token::Paren))
@@ -4669,7 +4663,7 @@ impl<'a> Parser<'a> {
                 // method macro.
 
                 let last_span = self.last_span;
-                self.complain_if_pub_macro(visa, last_span);
+                self.complain_if_pub_macro(vis, last_span);
 
                 let pth = self.parse_path(NoTypesAllowed);
                 self.expect(&token::Not);
@@ -4686,7 +4680,8 @@ impl<'a> Parser<'a> {
                 if delim != token::Brace {
                     self.expect(&token::Semi)
                 }
-                (ast::MethMac(m), self.span.hi, attrs)
+                (ast::MacImplItem(m), self.span.hi, attrs,
+                 token::special_idents::invalid)
             } else {
                 let unsafety = self.parse_unsafety();
                 let abi = if self.eat_keyword(keywords::Extern) {
@@ -4705,22 +4700,22 @@ impl<'a> Parser<'a> {
                 let body_span = body.span;
                 let mut new_attrs = attrs;
                 new_attrs.push_all(&inner_attrs[..]);
-                (ast::MethDecl(ident,
-                               generics,
-                               abi,
-                               explicit_self,
-                               unsafety,
-                               decl,
-                               body,
-                               visa),
-                 body_span.hi, new_attrs)
+                (MethodImplItem(ast::MethodSig {
+                    generics: generics,
+                    abi: abi,
+                    explicit_self: explicit_self,
+                    unsafety: unsafety,
+                    decl: decl
+                 }, body), body_span.hi, new_attrs, ident)
             }
         };
-        P(ast::Method {
-            attrs: new_attrs,
+        P(ImplItem {
             id: ast::DUMMY_NODE_ID,
-            span: mk_sp(lo, hi),
+            attrs: new_attrs,
+            vis: vis,
+            ident: ident,
             node: method_,
+            span: mk_sp(lo, hi),
         })
     }
 
@@ -4752,7 +4747,7 @@ impl<'a> Parser<'a> {
         (ident, ItemTrait(unsafety, tps, bounds, meths), None)
     }
 
-    fn parse_impl_items(&mut self) -> (Vec<ImplItem>, Vec<Attribute>) {
+    fn parse_impl_items(&mut self) -> (Vec<P<ImplItem>>, Vec<Attribute>) {
         let mut impl_items = Vec::new();
         self.expect(&token::OpenDelim(token::Brace));
         let (inner_attrs, mut method_attrs) =
@@ -4764,15 +4759,11 @@ impl<'a> Parser<'a> {
             }
 
             let vis = self.parse_visibility();
-            if self.eat_keyword(keywords::Type) {
-                impl_items.push(TypeImplItem(P(self.parse_typedef(
-                            method_attrs,
-                            vis))))
+            impl_items.push(if self.eat_keyword(keywords::Type) {
+                self.parse_assoc_ty_in_impl(method_attrs, vis)
             } else {
-                impl_items.push(MethodImplItem(self.parse_method(
-                            method_attrs,
-                            vis)));
-            }
+                self.parse_method(method_attrs, vis)
+            });
             method_attrs = vec![];
         }
         (impl_items, inner_attrs)
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 883c2295a36..07303ba51ff 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -12,8 +12,7 @@ pub use self::AnnNode::*;
 
 use abi;
 use ast;
-use ast::{MethodImplItem, RegionTyParamBound, TraitTyParamBound, TraitBoundModifier};
-use ast::{RequiredMethod, ProvidedMethod, TypeImplItem, TypeTraitItem};
+use ast::{RegionTyParamBound, TraitTyParamBound, TraitBoundModifier};
 use ast_util;
 use attr;
 use owned_slice::OwnedSlice;
@@ -360,14 +359,6 @@ pub fn generics_to_string(generics: &ast::Generics) -> String {
     $to_string(|s| s.print_generics(generics))
 }
 
-pub fn ty_method_to_string(p: &ast::TypeMethod) -> String {
-    $to_string(|s| s.print_ty_method(p))
-}
-
-pub fn method_to_string(p: &ast::Method) -> String {
-    $to_string(|s| s.print_method(p))
-}
-
 pub fn fn_block_to_string(p: &ast::FnDecl) -> String {
     $to_string(|s| s.print_fn_block_args(p))
 }
@@ -384,8 +375,9 @@ pub fn fun_to_string(decl: &ast::FnDecl, unsafety: ast::Unsafety, name: ast::Ide
                   opt_explicit_self: Option<&ast::ExplicitSelf_>,
                   generics: &ast::Generics) -> String {
     $to_string(|s| {
-        try!(s.print_fn(decl, Some(unsafety), abi::Rust,
-                        name, generics, opt_explicit_self, ast::Inherited));
+        try!(s.head(""));
+        try!(s.print_fn(decl, unsafety, abi::Rust, Some(name),
+                        generics, opt_explicit_self, ast::Inherited));
         try!(s.end()); // Close the head box
         s.end() // Close the outer box
     })
@@ -768,8 +760,10 @@ impl<'a> State<'a> {
         try!(self.print_outer_attributes(&item.attrs));
         match item.node {
             ast::ForeignItemFn(ref decl, ref generics) => {
-                try!(self.print_fn(&**decl, None, abi::Rust, item.ident, generics,
-                                   None, item.vis));
+                try!(self.head(""));
+                try!(self.print_fn(&**decl, ast::Unsafety::Normal,
+                                   abi::Rust, Some(item.ident),
+                                   generics, None, item.vis));
                 try!(self.end()); // end head-ibox
                 try!(word(&mut self.s, ";"));
                 self.end() // end the outer fn box
@@ -790,23 +784,24 @@ impl<'a> State<'a> {
         }
     }
 
-    fn print_associated_type(&mut self, typedef: &ast::AssociatedType)
-                             -> io::Result<()>
-    {
-        try!(self.print_outer_attributes(&typedef.attrs));
+    fn print_associated_type(&mut self,
+                             ident: ast::Ident,
+                             bounds: Option<&ast::TyParamBounds>,
+                             ty: Option<&ast::Ty>)
+                             -> io::Result<()> {
         try!(self.word_space("type"));
-        try!(self.print_ty_param(&typedef.ty_param));
+        try!(self.print_ident(ident));
+        if let Some(bounds) = bounds {
+            try!(self.print_bounds(":", bounds));
+        }
+        if let Some(ty) = ty {
+            try!(space(&mut self.s));
+            try!(self.word_space("="));
+            try!(self.print_type(ty));
+        }
         word(&mut self.s, ";")
     }
 
-    fn print_typedef(&mut self, typedef: &ast::Typedef) -> io::Result<()> {
-        try!(self.word_space("type"));
-        try!(self.print_ident(typedef.ident));
-        try!(space(&mut self.s));
-        try!(self.word_space("="));
-        try!(self.print_type(&*typedef.typ));
-        word(&mut self.s, ";")
-    }
 
     /// Pretty-print an item
     pub fn print_item(&mut self, item: &ast::Item) -> io::Result<()> {
@@ -869,11 +864,12 @@ impl<'a> State<'a> {
                 try!(self.end()); // end the outer cbox
             }
             ast::ItemFn(ref decl, unsafety, abi, ref typarams, ref body) => {
+                try!(self.head(""));
                 try!(self.print_fn(
-                    &**decl,
-                    Some(unsafety),
+                    decl,
+                    unsafety,
                     abi,
-                    item.ident,
+                    Some(item.ident),
                     typarams,
                     None,
                     item.vis
@@ -977,18 +973,11 @@ impl<'a> State<'a> {
                 try!(self.bopen());
                 try!(self.print_inner_attributes(&item.attrs));
                 for impl_item in impl_items {
-                    match *impl_item {
-                        ast::MethodImplItem(ref meth) => {
-                            try!(self.print_method(&**meth));
-                        }
-                        ast::TypeImplItem(ref typ) => {
-                            try!(self.print_typedef(&**typ));
-                        }
-                    }
+                    try!(self.print_impl_item(impl_item));
                 }
                 try!(self.bclose(item.span));
             }
-            ast::ItemTrait(unsafety, ref generics, ref bounds, ref methods) => {
+            ast::ItemTrait(unsafety, ref generics, ref bounds, ref trait_items) => {
                 try!(self.head(""));
                 try!(self.print_visibility(item.vis));
                 try!(self.print_unsafety(unsafety));
@@ -1009,8 +998,8 @@ impl<'a> State<'a> {
                 try!(self.print_where_clause(generics));
                 try!(word(&mut self.s, " "));
                 try!(self.bopen());
-                for meth in methods {
-                    try!(self.print_trait_method(meth));
+                for trait_item in trait_items {
+                    try!(self.print_trait_item(trait_item));
                 }
                 try!(self.bclose(item.span));
             }
@@ -1242,60 +1231,61 @@ impl<'a> State<'a> {
         }
     }
 
-    pub fn print_ty_method(&mut self, m: &ast::TypeMethod) -> io::Result<()> {
-        try!(self.hardbreak_if_not_bol());
-        try!(self.maybe_print_comment(m.span.lo));
-        try!(self.print_outer_attributes(&m.attrs));
-        try!(self.print_ty_fn(m.abi,
-                              m.unsafety,
-                              &*m.decl,
-                              Some(m.ident),
-                              &m.generics,
-                              Some(&m.explicit_self.node)));
-        word(&mut self.s, ";")
+    pub fn print_method_sig(&mut self,
+                            ident: ast::Ident,
+                            m: &ast::MethodSig,
+                            vis: ast::Visibility)
+                            -> io::Result<()> {
+        self.print_fn(&m.decl,
+                      m.unsafety,
+                      m.abi,
+                      Some(ident),
+                      &m.generics,
+                      Some(&m.explicit_self.node),
+                      vis)
     }
 
-    pub fn print_trait_method(&mut self,
-                              m: &ast::TraitItem) -> io::Result<()> {
-        match *m {
-            RequiredMethod(ref ty_m) => self.print_ty_method(ty_m),
-            ProvidedMethod(ref m) => self.print_method(&**m),
-            TypeTraitItem(ref t) => self.print_associated_type(&**t),
+    pub fn print_trait_item(&mut self, ti: &ast::TraitItem)
+                            -> io::Result<()> {
+        try!(self.hardbreak_if_not_bol());
+        try!(self.maybe_print_comment(ti.span.lo));
+        try!(self.print_outer_attributes(&ti.attrs));
+        match ti.node {
+            ast::MethodTraitItem(ref sig, ref body) => {
+                if body.is_some() {
+                    try!(self.head(""));
+                }
+                try!(self.print_method_sig(ti.ident, sig, ast::Inherited));
+                if let Some(ref body) = *body {
+                    try!(self.nbsp());
+                    self.print_block_with_attrs(body, &ti.attrs)
+                } else {
+                    word(&mut self.s, ";")
+                }
+            }
+            ast::TypeTraitItem(ref bounds, ref default) => {
+                self.print_associated_type(ti.ident, Some(bounds),
+                                           default.as_ref().map(|ty| &**ty))
+            }
         }
     }
 
     pub fn print_impl_item(&mut self, ii: &ast::ImplItem) -> io::Result<()> {
-        match *ii {
-            MethodImplItem(ref m) => self.print_method(&**m),
-            TypeImplItem(ref td) => self.print_typedef(&**td),
-        }
-    }
-
-    pub fn print_method(&mut self, meth: &ast::Method) -> io::Result<()> {
         try!(self.hardbreak_if_not_bol());
-        try!(self.maybe_print_comment(meth.span.lo));
-        try!(self.print_outer_attributes(&meth.attrs));
-        match meth.node {
-            ast::MethDecl(ident,
-                          ref generics,
-                          abi,
-                          ref explicit_self,
-                          unsafety,
-                          ref decl,
-                          ref body,
-                          vis) => {
-                try!(self.print_fn(&**decl,
-                                   Some(unsafety),
-                                   abi,
-                                   ident,
-                                   generics,
-                                   Some(&explicit_self.node),
-                                   vis));
-                try!(word(&mut self.s, " "));
-                self.print_block_with_attrs(&**body, &meth.attrs)
-            },
-            ast::MethMac(codemap::Spanned { node: ast::MacInvocTT(ref pth, ref tts, _),
-                                            ..}) => {
+        try!(self.maybe_print_comment(ii.span.lo));
+        try!(self.print_outer_attributes(&ii.attrs));
+        match ii.node {
+            ast::MethodImplItem(ref sig, ref body) => {
+                try!(self.head(""));
+                try!(self.print_method_sig(ii.ident, sig, ii.vis));
+                try!(self.nbsp());
+                self.print_block_with_attrs(body, &ii.attrs)
+            }
+            ast::TypeImplItem(ref ty) => {
+                self.print_associated_type(ii.ident, None, Some(ty))
+            }
+            ast::MacImplItem(codemap::Spanned { node: ast::MacInvocTT(ref pth, ref tts, _),
+                                                ..}) => {
                 // code copied from ItemMac:
                 try!(self.print_path(pth, false, 0));
                 try!(word(&mut self.s, "! "));
@@ -2326,16 +2316,18 @@ impl<'a> State<'a> {
 
     pub fn print_fn(&mut self,
                     decl: &ast::FnDecl,
-                    unsafety: Option<ast::Unsafety>,
+                    unsafety: ast::Unsafety,
                     abi: abi::Abi,
-                    name: ast::Ident,
+                    name: Option<ast::Ident>,
                     generics: &ast::Generics,
                     opt_explicit_self: Option<&ast::ExplicitSelf_>,
                     vis: ast::Visibility) -> io::Result<()> {
-        try!(self.head(""));
         try!(self.print_fn_header_info(unsafety, abi, vis));
-        try!(self.nbsp());
-        try!(self.print_ident(name));
+
+        if let Some(name) = name {
+            try!(self.nbsp());
+            try!(self.print_ident(name));
+        }
         try!(self.print_generics(generics));
         try!(self.print_fn_args_and_ret(decl, opt_explicit_self));
         self.print_where_clause(generics)
@@ -2702,25 +2694,14 @@ impl<'a> State<'a> {
                        abi: abi::Abi,
                        unsafety: ast::Unsafety,
                        decl: &ast::FnDecl,
-                       id: Option<ast::Ident>,
+                       name: Option<ast::Ident>,
                        generics: &ast::Generics,
                        opt_explicit_self: Option<&ast::ExplicitSelf_>)
                        -> io::Result<()> {
         try!(self.ibox(indent_unit));
-        try!(self.print_fn_header_info(Some(unsafety), abi, ast::Inherited));
-
-        match id {
-            Some(id) => {
-                try!(word(&mut self.s, " "));
-                try!(self.print_ident(id));
-            }
-            _ => ()
-        }
-
-        try!(self.print_generics(generics));
-        try!(zerobreak(&mut self.s));
-        try!(self.print_fn_args_and_ret(decl, opt_explicit_self));
-        try!(self.print_where_clause(generics));
+        try!(self.print_fn(decl, unsafety, abi, name,
+                           generics, opt_explicit_self,
+                           ast::Inherited));
         self.end()
     }
 
@@ -2942,14 +2923,6 @@ impl<'a> State<'a> {
         }
     }
 
-    pub fn print_opt_unsafety(&mut self,
-                            opt_unsafety: Option<ast::Unsafety>) -> io::Result<()> {
-        match opt_unsafety {
-            Some(unsafety) => self.print_unsafety(unsafety),
-            None => Ok(())
-        }
-    }
-
     pub fn print_opt_abi_and_extern_if_nondefault(&mut self,
                                                   opt_abi: Option<abi::Abi>)
         -> io::Result<()> {
@@ -2975,11 +2948,11 @@ impl<'a> State<'a> {
     }
 
     pub fn print_fn_header_info(&mut self,
-                                opt_unsafety: Option<ast::Unsafety>,
+                                unsafety: ast::Unsafety,
                                 abi: abi::Abi,
                                 vis: ast::Visibility) -> io::Result<()> {
         try!(word(&mut self.s, &visibility_qualified(vis, "")));
-        try!(self.print_opt_unsafety(opt_unsafety));
+        try!(self.print_unsafety(unsafety));
 
         if abi != abi::Rust {
             try!(self.word_nbsp("extern"));
diff --git a/src/libsyntax/visit.rs b/src/libsyntax/visit.rs
index 33d8d56b4b1..638ddd3ea2e 100644
--- a/src/libsyntax/visit.rs
+++ b/src/libsyntax/visit.rs
@@ -38,7 +38,7 @@ pub enum FnKind<'a> {
     FkItemFn(Ident, &'a Generics, Unsafety, Abi),
 
     /// fn foo(&self)
-    FkMethod(Ident, &'a Generics, &'a Method),
+    FkMethod(Ident, &'a MethodSig),
 
     /// |x, y| ...
     /// proc(x, y) ...
@@ -77,8 +77,8 @@ pub trait Visitor<'v> : Sized {
     fn visit_fn(&mut self, fk: FnKind<'v>, fd: &'v FnDecl, b: &'v Block, s: Span, _: NodeId) {
         walk_fn(self, fk, fd, b, s)
     }
-    fn visit_ty_method(&mut self, t: &'v TypeMethod) { walk_ty_method(self, t) }
-    fn visit_trait_item(&mut self, t: &'v TraitItem) { walk_trait_item(self, t) }
+    fn visit_trait_item(&mut self, ti: &'v TraitItem) { walk_trait_item(self, ti) }
+    fn visit_impl_item(&mut self, ii: &'v ImplItem) { walk_impl_item(self, ii) }
     fn visit_trait_ref(&mut self, t: &'v TraitRef) { walk_trait_ref(self, t) }
     fn visit_ty_param_bound(&mut self, bounds: &'v TyParamBound) {
         walk_ty_param_bound(self, bounds)
@@ -143,13 +143,7 @@ pub fn walk_inlined_item<'v,V>(visitor: &mut V, item: &'v InlinedItem)
         IIItem(ref i) => visitor.visit_item(&**i),
         IIForeign(ref i) => visitor.visit_foreign_item(&**i),
         IITraitItem(_, ref ti) => visitor.visit_trait_item(ti),
-        IIImplItem(_, MethodImplItem(ref m)) => {
-            walk_method_helper(visitor, &**m)
-        }
-        IIImplItem(_, TypeImplItem(ref typedef)) => {
-            visitor.visit_ident(typedef.span, typedef.ident);
-            visitor.visit_ty(&*typedef.typ);
-        }
+        IIImplItem(_, ref ii) => visitor.visit_impl_item(ii),
     }
 }
 
@@ -202,8 +196,6 @@ pub fn walk_explicit_self<'v, V: Visitor<'v>>(visitor: &mut V,
     }
 }
 
-/// Like with walk_method_helper this doesn't correspond to a method
-/// in Visitor, and so it gets a _helper suffix.
 pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
                                   trait_ref: &'v PolyTraitRef,
                                   _modifier: &'v TraitBoundModifier)
@@ -213,8 +205,6 @@ pub fn walk_poly_trait_ref<'v, V>(visitor: &mut V,
     visitor.visit_trait_ref(&trait_ref.trait_ref);
 }
 
-/// Like with walk_method_helper this doesn't correspond to a method
-/// in Visitor, and so it gets a _helper suffix.
 pub fn walk_trait_ref<'v,V>(visitor: &mut V,
                                    trait_ref: &'v TraitRef)
     where V: Visitor<'v>
@@ -294,15 +284,7 @@ pub fn walk_item<'v, V: Visitor<'v>>(visitor: &mut V, item: &'v Item) {
             }
             visitor.visit_ty(&**typ);
             for impl_item in impl_items {
-                match *impl_item {
-                    MethodImplItem(ref method) => {
-                        walk_method_helper(visitor, &**method)
-                    }
-                    TypeImplItem(ref typedef) => {
-                        visitor.visit_ident(typedef.span, typedef.ident);
-                        visitor.visit_ty(&*typedef.typ);
-                    }
-                }
+                visitor.visit_impl_item(impl_item);
             }
         }
         ItemStruct(ref struct_definition, ref generics) => {
@@ -561,15 +543,11 @@ pub fn walk_ty_param_bound<'v, V: Visitor<'v>>(visitor: &mut V,
     }
 }
 
-pub fn walk_ty_param<'v, V: Visitor<'v>>(visitor: &mut V, param: &'v TyParam) {
-    visitor.visit_ident(param.span, param.ident);
-    walk_ty_param_bounds_helper(visitor, &param.bounds);
-    walk_ty_opt(visitor, &param.default);
-}
-
 pub fn walk_generics<'v, V: Visitor<'v>>(visitor: &mut V, generics: &'v Generics) {
-    for type_parameter in &*generics.ty_params {
-        walk_ty_param(visitor, type_parameter);
+    for param in &*generics.ty_params {
+        visitor.visit_ident(param.span, param.ident);
+        walk_ty_param_bounds_helper(visitor, &param.bounds);
+        walk_ty_opt(visitor, &param.default);
     }
     walk_lifetime_decls_helper(visitor, &generics.lifetimes);
     for predicate in &generics.where_clause.predicates {
@@ -614,28 +592,6 @@ pub fn walk_fn_decl<'v, V: Visitor<'v>>(visitor: &mut V, function_declaration: &
     walk_fn_ret_ty(visitor, &function_declaration.output)
 }
 
-// Note: there is no visit_method() method in the visitor, instead override
-// visit_fn() and check for FkMethod().  I named this visit_method_helper()
-// because it is not a default impl of any method, though I doubt that really
-// clarifies anything. - Niko
-pub fn walk_method_helper<'v, V: Visitor<'v>>(visitor: &mut V, method: &'v Method) {
-    match method.node {
-        MethDecl(ident, ref generics, _, _, _, ref decl, ref body, _) => {
-            visitor.visit_ident(method.span, ident);
-            visitor.visit_fn(FkMethod(ident, generics, method),
-                             &**decl,
-                             &**body,
-                             method.span,
-                             method.id);
-            for attr in &method.attrs {
-                visitor.visit_attribute(attr);
-            }
-
-        },
-        MethMac(ref mac) => visitor.visit_mac(mac)
-    }
-}
-
 pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
                                    function_kind: FnKind<'v>,
                                    function_declaration: &'v FnDecl,
@@ -647,14 +603,9 @@ pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
         FkItemFn(_, generics, _, _) => {
             visitor.visit_generics(generics);
         }
-        FkMethod(_, generics, method) => {
-            visitor.visit_generics(generics);
-            match method.node {
-                MethDecl(_, _, _, ref explicit_self, _, _, _, _) =>
-                    visitor.visit_explicit_self(explicit_self),
-                MethMac(ref mac) =>
-                    visitor.visit_mac(mac)
-            }
+        FkMethod(_, sig) => {
+            visitor.visit_generics(&sig.generics);
+            visitor.visit_explicit_self(&sig.explicit_self);
         }
         FkFnBlock(..) => {}
     }
@@ -662,25 +613,43 @@ pub fn walk_fn<'v, V: Visitor<'v>>(visitor: &mut V,
     visitor.visit_block(function_body)
 }
 
-pub fn walk_ty_method<'v, V: Visitor<'v>>(visitor: &mut V, method_type: &'v TypeMethod) {
-    visitor.visit_ident(method_type.span, method_type.ident);
-    visitor.visit_explicit_self(&method_type.explicit_self);
-    for argument_type in &method_type.decl.inputs {
-        visitor.visit_ty(&*argument_type.ty)
-    }
-    visitor.visit_generics(&method_type.generics);
-    walk_fn_ret_ty(visitor, &method_type.decl.output);
-    for attr in &method_type.attrs {
+pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_item: &'v TraitItem) {
+    visitor.visit_ident(trait_item.span, trait_item.ident);
+    for attr in &trait_item.attrs {
         visitor.visit_attribute(attr);
     }
+    match trait_item.node {
+        MethodTraitItem(ref sig, None) => {
+            visitor.visit_explicit_self(&sig.explicit_self);
+            visitor.visit_generics(&sig.generics);
+            walk_fn_decl(visitor, &sig.decl);
+        }
+        MethodTraitItem(ref sig, Some(ref body)) => {
+            visitor.visit_fn(FkMethod(trait_item.ident, sig), &sig.decl,
+                             body, trait_item.span, trait_item.id);
+        }
+        TypeTraitItem(ref bounds, ref default) => {
+            walk_ty_param_bounds_helper(visitor, bounds);
+            walk_ty_opt(visitor, default);
+        }
+    }
 }
 
-pub fn walk_trait_item<'v, V: Visitor<'v>>(visitor: &mut V, trait_method: &'v TraitItem) {
-    match *trait_method {
-        RequiredMethod(ref method_type) => visitor.visit_ty_method(method_type),
-        ProvidedMethod(ref method) => walk_method_helper(visitor, &**method),
-        TypeTraitItem(ref associated_type) => {
-            walk_ty_param(visitor, &associated_type.ty_param);
+pub fn walk_impl_item<'v, V: Visitor<'v>>(visitor: &mut V, impl_item: &'v ImplItem) {
+    visitor.visit_ident(impl_item.span, impl_item.ident);
+    for attr in &impl_item.attrs {
+        visitor.visit_attribute(attr);
+    }
+    match impl_item.node {
+        MethodImplItem(ref sig, ref body) => {
+            visitor.visit_fn(FkMethod(impl_item.ident, sig), &sig.decl,
+                             body, impl_item.span, impl_item.id);
+        }
+        TypeImplItem(ref ty) => {
+            visitor.visit_ty(ty);
+        }
+        MacImplItem(ref mac) => {
+            visitor.visit_mac(mac);
         }
     }
 }