De-share trait_ref

Also, makes the pretty-printer use & instead of @ as much as possible,
which will help with later changes, though in the interim has produced
some... interesting constructs.

Author: James Miller

src/librustc/front/config.rs

@@ -98,10 +98,10 @@ fn fold_foreign_mod(
 fn fold_item_underscore(cx: @Context, item: &ast::item_,
                         fld: @fold::ast_fold) -> ast::item_ {
     let item = match *item {
-        ast::item_impl(ref a, b, c, ref methods) => {
+        ast::item_impl(ref a, ref b, c, ref methods) => {
             let methods = methods.iter().filter(|m| method_in_cfg(cx, **m))
                 .transform(|x| *x).collect();
-            ast::item_impl(/*bad*/ copy *a, b, c, methods)
+            ast::item_impl(/*bad*/ copy *a, /*bad*/ copy *b, c, methods)
         }
         ast::item_trait(ref a, ref b, ref methods) => {
             let methods = methods.iter().filter(|m| trait_method_in_cfg(cx, *m) )

src/librustc/metadata/decoder.rs

@@ -1141,7 +1141,7 @@ fn list_crate_attributes(intr: @ident_interner, md: ebml::Doc, hash: &str,
 
     let r = get_attributes(md);
     for r.iter().advance |attr| {
-        out.write_str(fmt!("%s\n", pprust::attribute_to_str(*attr, intr)));
+        out.write_str(fmt!("%s\n", pprust::attribute_to_str(attr, intr)));
     }
 
     out.write_str("\n\n");

src/librustc/metadata/encoder.rs

@@ -1003,7 +1003,7 @@ fn encode_info_for_item(ecx: &EncodeContext,
                                         index);
         }
       }
-      item_impl(ref generics, opt_trait, ty, ref methods) => {
+      item_impl(ref generics, ref opt_trait, ty, ref methods) => {
         add_to_index();
         ebml_w.start_tag(tag_items_data_item);
         encode_def_id(ebml_w, local_def(item.id));

src/librustc/middle/kind.rs

@@ -117,7 +117,7 @@ fn check_item(item: @item, (cx, visitor): (Context, visit::vt<Context>)) {
     // If this is a destructor, check kinds.
     if !attrs_contains_name(item.attrs, "unsafe_destructor") {
         match item.node {
-            item_impl(_, Some(trait_ref), self_type, _) => {
+            item_impl(_, Some(ref trait_ref), self_type, _) => {
                 match cx.tcx.def_map.find(&trait_ref.ref_id) {
                     None => cx.tcx.sess.bug("trait ref not in def map!"),
                     Some(&trait_def) => {

src/librustc/middle/reachable.rs

@@ -141,7 +141,7 @@ impl ReachableContext {
                             }
                         }
                     }
-                    item_impl(ref generics, trait_ref, _, ref methods) => {
+                    item_impl(ref generics, ref trait_ref, _, ref methods) => {
                         // XXX(pcwalton): We conservatively assume any methods
                         // on a trait implementation are reachable, when this
                         // is not the case. We could be more precise by only

src/librustc/middle/resolve.rs

@@ -3533,7 +3533,7 @@ impl Resolver {
             }
 
             item_impl(ref generics,
-                      implemented_traits,
+                      ref implemented_traits,
                       self_type,
                       ref methods) => {
                 self.resolve_implementation(item.id,
@@ -3811,7 +3811,7 @@ impl Resolver {
                                         type_parameter_bound: &TyParamBound,
                                         visitor: ResolveVisitor) {
         match *type_parameter_bound {
-            TraitTyParamBound(tref) => {
+            TraitTyParamBound(ref tref) => {
                 self.resolve_trait_reference(tref, visitor, TraitBoundingTypeParameter)
             }
             RegionTyParamBound => {}
@@ -3913,7 +3913,7 @@ impl Resolver {
     pub fn resolve_implementation(@mut self,
                                   id: node_id,
                                   generics: &Generics,
-                                  opt_trait_reference: Option<@trait_ref>,
+                                  opt_trait_reference: &Option<trait_ref>,
                                   self_type: @Ty,
                                   methods: &[@method],
                                   visitor: ResolveVisitor) {
@@ -3929,7 +3929,7 @@ impl Resolver {
             // Resolve the trait reference, if necessary.
             let original_trait_refs;
             match opt_trait_reference {
-                Some(trait_reference) => {
+                &Some(ref trait_reference) => {
                     self.resolve_trait_reference(trait_reference, visitor, TraitImplementation);
 
                     // Record the current set of trait references.
@@ -3944,7 +3944,7 @@ impl Resolver {
                         &mut self.current_trait_refs,
                         Some(new_trait_refs)));
                 }
-                None => {
+                &None => {
                     original_trait_refs = None;
                 }
             }

src/librustc/middle/ty.rs

@@ -3624,12 +3624,12 @@ pub fn impl_trait_ref(cx: ctxt, id: ast::def_id) -> Option<@TraitRef> {
             debug!("(impl_trait_ref) searching for trait impl %?", id);
             match cx.items.find(&id.node) {
                 Some(&ast_map::node_item(@ast::item {
-                                         node: ast::item_impl(_, opt_trait, _, _),
+                                         node: ast::item_impl(_, ref opt_trait, _, _),
                                          _},
                                          _)) => {
                     match opt_trait {
-                        Some(t) => Some(ty::node_id_to_trait_ref(cx, t.ref_id)),
-                        None => None
+                        &Some(ref t) => Some(ty::node_id_to_trait_ref(cx, t.ref_id)),
+                        &None => None
                     }
                 }
                 _ => None

src/librustc/middle/typeck/astconv.rs

@@ -764,7 +764,7 @@ fn conv_builtin_bounds(tcx: ty::ctxt, ast_bounds: &Option<OptVec<ast::TyParamBou
             let mut builtin_bounds = ty::EmptyBuiltinBounds();
             for bound_vec.iter().advance |ast_bound| {
                 match *ast_bound {
-                    ast::TraitTyParamBound(b) => {
+                    ast::TraitTyParamBound(ref b) => {
                         match lookup_def_tcx(tcx, b.path.span, b.ref_id) {
                             ast::def_trait(trait_did) => {
                                 if try_add_builtin_trait(tcx,

src/librustc/middle/typeck/coherence.rs

@@ -207,9 +207,11 @@ impl CoherenceChecker {
 //                       self.crate_context.tcx.sess.str_of(item.ident));
 
                 match item.node {
-                    item_impl(_, opt_trait, _, _) => {
-                        self.check_implementation(item,
-                                                  opt_trait.iter().transform(|&x| x).collect());
+                    item_impl(_, ref opt_trait, _, _) => {
+                        let opt_trait : ~[trait_ref] = opt_trait.iter()
+                                                                .transform(|&x| x)
+                                                                .collect();
+                        self.check_implementation(item, opt_trait);
                     }
                     _ => {
                         // Nothing to do.
@@ -238,7 +240,7 @@ impl CoherenceChecker {
 
     pub fn check_implementation(&self,
                                 item: @item,
-                                associated_traits: ~[@trait_ref]) {
+                                associated_traits: &[trait_ref]) {
         let tcx = self.crate_context.tcx;
         let self_type = ty::lookup_item_type(tcx, local_def(item.id));
 
@@ -646,7 +648,7 @@ impl CoherenceChecker {
                                               a trait or new type instead");
                         }
                     }
-                    item_impl(_, Some(trait_ref), _, _) => {
+                    item_impl(_, Some(ref trait_ref), _, _) => {
                         // `for_ty` is `Type` in `impl Trait for Type`
                         let for_ty =
                             ty::node_id_to_type(self.crate_context.tcx,
@@ -678,7 +680,7 @@ impl CoherenceChecker {
         })));
     }
 
-    pub fn trait_ref_to_trait_def_id(&self, trait_ref: @trait_ref) -> def_id {
+    pub fn trait_ref_to_trait_def_id(&self, trait_ref: &trait_ref) -> def_id {
         let def_map = self.crate_context.tcx.def_map;
         let trait_def = def_map.get_copy(&trait_ref.ref_id);
         let trait_id = def_id_of_def(trait_def);
@@ -805,7 +807,7 @@ impl CoherenceChecker {
                 // Check that we have implementations of every trait method
                 for trait_refs.iter().advance |trait_ref| {
                     let trait_did =
-                        self.trait_ref_to_trait_def_id(*trait_ref);
+                        self.trait_ref_to_trait_def_id(trait_ref);
                     self.please_check_that_trait_methods_are_implemented(
                         &mut methods,
                         trait_did,
@@ -817,7 +819,7 @@ impl CoherenceChecker {
                 // if a method of that name is not inherent to the
                 // impl, use the provided definition in the trait.
                 for trait_refs.iter().advance |trait_ref| {
-                    let trait_did = self.trait_ref_to_trait_def_id(*trait_ref);
+                    let trait_did = self.trait_ref_to_trait_def_id(trait_ref);
                     self.add_provided_methods_to_impl(
                         &mut methods,
                         &trait_did,

src/librustc/middle/typeck/collect.rs

@@ -378,15 +378,15 @@ pub fn ensure_supertraits(ccx: &CrateCtxt,
                           id: ast::node_id,
                           sp: codemap::span,
                           rp: Option<ty::region_variance>,
-                          ast_trait_refs: &[@ast::trait_ref],
+                          ast_trait_refs: &[ast::trait_ref],
                           generics: &ast::Generics)
 {
     let tcx = ccx.tcx;
     if tcx.supertraits.contains_key(&local_def(id)) { return; }
 
     let self_ty = ty::mk_self(ccx.tcx, local_def(id));
     let mut ty_trait_refs: ~[@ty::TraitRef] = ~[];
-    for ast_trait_refs.iter().advance |&ast_trait_ref| {
+    for ast_trait_refs.iter().advance |ast_trait_ref| {
         let trait_ref = instantiate_trait_ref(ccx, ast_trait_ref, rp,
                                               generics, self_ty);
 
@@ -441,7 +441,7 @@ pub fn compare_impl_method(tcx: ty::ctxt,
                 fmt!("method `%s` has a `%s` declaration in the impl, \
                       but not in the trait",
                      tcx.sess.str_of(trait_m.ident),
-                     explicit_self_to_str(impl_m.explicit_self, tcx.sess.intr())));
+                     explicit_self_to_str(&impl_m.explicit_self, tcx.sess.intr())));
             return;
         }
         (_, &ast::sty_static) => {
@@ -450,7 +450,7 @@ pub fn compare_impl_method(tcx: ty::ctxt,
                 fmt!("method `%s` has a `%s` declaration in the trait, \
                       but not in the impl",
                      tcx.sess.str_of(trait_m.ident),
-                     explicit_self_to_str(trait_m.explicit_self, tcx.sess.intr())));
+                     explicit_self_to_str(&trait_m.explicit_self, tcx.sess.intr())));
             return;
         }
         _ => {
@@ -813,7 +813,7 @@ pub fn convert(ccx: &CrateCtxt, it: &ast::item) {
                                generics,
                                rp);
       }
-      ast::item_impl(ref generics, opt_trait_ref, selfty, ref ms) => {
+      ast::item_impl(ref generics, ref opt_trait_ref, selfty, ref ms) => {
         let i_ty_generics = ty_generics(ccx, rp, generics, 0);
         let region_parameterization =
             RegionParameterization::from_variance_and_generics(rp, generics);
@@ -839,7 +839,7 @@ pub fn convert(ccx: &CrateCtxt, it: &ast::item) {
                                   &i_ty_generics, generics,
                                   parent_visibility);
         for opt_trait_ref.iter().advance |t| {
-            check_methods_against_trait(ccx, generics, rp, selfty, *t, cms);
+            check_methods_against_trait(ccx, generics, rp, selfty, t, cms);
         }
       }
       ast::item_trait(ref generics, ref supertraits, ref trait_methods) => {
@@ -1184,7 +1184,7 @@ pub fn ty_generics(ccx: &CrateCtxt,
         };
         for ast_bounds.iter().advance |ast_bound| {
             match *ast_bound {
-                TraitTyParamBound(b) => {
+                TraitTyParamBound(ref b) => {
                     let ty = ty::mk_param(ccx.tcx, param_ty.idx, param_ty.def_id);
                     let trait_ref = instantiate_trait_ref(ccx, b, rp, generics, ty);
                     if !astconv::try_add_builtin_trait(

src/libsyntax/ast.rs

@@ -132,7 +132,7 @@ pub static crate_node_id: node_id = 0;
 // the "special" built-in traits (see middle::lang_items) and
 // detects Copy, Send, Send, and Freeze.
 pub enum TyParamBound {
-    TraitTyParamBound(@trait_ref),
+    TraitTyParamBound(trait_ref),
     RegionTyParamBound
 }
 
@@ -1002,9 +1002,9 @@ pub enum item_ {
     item_ty(@Ty, Generics),
     item_enum(enum_def, Generics),
     item_struct(@struct_def, Generics),
-    item_trait(Generics, ~[@trait_ref], ~[trait_method]),
+    item_trait(Generics, ~[trait_ref], ~[trait_method]),
     item_impl(Generics,
-              Option<@trait_ref>, // (optional) trait this impl implements
+              Option<trait_ref>, // (optional) trait this impl implements
               @Ty, // self
               ~[@method]),
     // a macro invocation (which includes macro definition)

src/libsyntax/ast_util.rs

@@ -580,7 +580,7 @@ pub fn view_path_id(p: &view_path) -> node_id {
 
 /// Returns true if the given struct def is tuple-like; i.e. that its fields
 /// are unnamed.
-pub fn struct_def_is_tuple_like(struct_def: @ast::struct_def) -> bool {
+pub fn struct_def_is_tuple_like(struct_def: &ast::struct_def) -> bool {
     struct_def.ctor_id.is_some()
 }
 

src/libsyntax/ext/build.rs

@@ -68,7 +68,7 @@ pub trait AstBuilder {
 
     fn typaram(&self, id: ast::ident, bounds: @OptVec<ast::TyParamBound>) -> ast::TyParam;
 
-    fn trait_ref(&self, path: ast::Path) -> @ast::trait_ref;
+    fn trait_ref(&self, path: ast::Path) -> ast::trait_ref;
     fn typarambound(&self, path: ast::Path) -> ast::TyParamBound;
     fn lifetime(&self, span: span, ident: ast::ident) -> ast::Lifetime;
 
@@ -358,8 +358,8 @@ impl AstBuilder for @ExtCtxt {
         }
     }
 
-    fn trait_ref(&self, path: ast::Path) -> @ast::trait_ref {
-        @ast::trait_ref {
+    fn trait_ref(&self, path: ast::Path) -> ast::trait_ref {
+        ast::trait_ref {
             path: path,
             ref_id: self.next_id()
         }

src/libsyntax/ext/log_syntax.rs

@@ -26,7 +26,7 @@ pub fn expand_syntax_ext(cx: @ExtCtxt,
     cx.print_backtrace();
     io::stdout().write_line(
         print::pprust::tt_to_str(
-            ast::tt_delim(vec::to_owned(tt)),
+            &ast::tt_delim(vec::to_owned(tt)),
             get_ident_interner()));
 
     //trivial expression

src/libsyntax/ext/tt/macro_rules.rs

@@ -82,7 +82,7 @@ pub fn add_new_extension(cx: @ExtCtxt,
             io::println(fmt!("%s! { %s }",
                              cx.str_of(name),
                              print::pprust::tt_to_str(
-                                 ast::tt_delim(vec::to_owned(arg)),
+                                 &ast::tt_delim(vec::to_owned(arg)),
                                  get_ident_interner())));
         }
 

src/libsyntax/fold.rs

@@ -162,7 +162,7 @@ pub fn fold_fn_decl(decl: &ast::fn_decl, fld: @ast_fold) -> ast::fn_decl {
 
 fn fold_ty_param_bound(tpb: &TyParamBound, fld: @ast_fold) -> TyParamBound {
     match *tpb {
-        TraitTyParamBound(ty) => TraitTyParamBound(fold_trait_ref(ty, fld)),
+        TraitTyParamBound(ref ty) => TraitTyParamBound(fold_trait_ref(ty, fld)),
         RegionTyParamBound => RegionTyParamBound
     }
 }
@@ -296,10 +296,10 @@ pub fn noop_fold_item_underscore(i: &item_, fld: @ast_fold) -> item_ {
             let struct_def = fold_struct_def(*struct_def, fld);
             item_struct(struct_def, /* FIXME (#2543) */ copy *generics)
         }
-        item_impl(ref generics, ifce, ty, ref methods) => {
+        item_impl(ref generics, ref ifce, ty, ref methods) => {
             item_impl(
                 fold_generics(generics, fld),
-                ifce.map(|p| fold_trait_ref(*p, fld)),
+                ifce.map(|p| fold_trait_ref(p, fld)),
                 fld.fold_ty(ty),
                 methods.map(|x| fld.fold_method(*x))
             )
@@ -313,7 +313,7 @@ pub fn noop_fold_item_underscore(i: &item_, fld: @ast_fold) -> item_ {
             };
             item_trait(
                 fold_generics(generics, fld),
-                traits.map(|p| fold_trait_ref(*p, fld)),
+                traits.map(|p| fold_trait_ref(p, fld)),
                 methods
             )
         }
@@ -335,8 +335,8 @@ fn fold_struct_def(struct_def: @ast::struct_def, fld: @ast_fold)
     }
 }
 
-fn fold_trait_ref(p: @trait_ref, fld: @ast_fold) -> @trait_ref {
-    @ast::trait_ref {
+fn fold_trait_ref(p: &trait_ref, fld: @ast_fold) -> trait_ref {
+    ast::trait_ref {
         path: fld.fold_path(&p.path),
         ref_id: fld.new_id(p.ref_id),
     }

src/libsyntax/parse/parser.rs

@@ -3566,7 +3566,7 @@ impl Parser {
             // New-style trait. Reinterpret the type as a trait.
             let opt_trait_ref = match ty.node {
                 ty_path(ref path, @None, node_id) => {
-                    Some(@trait_ref {
+                    Some(trait_ref {
                         path: /* bad */ copy *path,
                         ref_id: node_id
                     })
@@ -3608,15 +3608,15 @@ impl Parser {
     }
 
     // parse a::B<~str,int>
-    fn parse_trait_ref(&self) -> @trait_ref {
-        @ast::trait_ref {
+    fn parse_trait_ref(&self) -> trait_ref {
+        ast::trait_ref {
             path: self.parse_path_with_tps(false),
             ref_id: self.get_id(),
         }
     }
 
     // parse B + C<~str,int> + D
-    fn parse_trait_ref_list(&self, ket: &token::Token) -> ~[@trait_ref] {
+    fn parse_trait_ref_list(&self, ket: &token::Token) -> ~[trait_ref] {
         self.parse_seq_to_before_end(
             ket,
             seq_sep_trailing_disallowed(token::BINOP(token::PLUS)),