Use numeric field `Name`s ("0", "1" etc) for positional fields

src/librustc/front/map/definitions.rs

@@ -83,7 +83,7 @@ pub enum DefPathData {
     TypeParam(ast::Name),
     LifetimeDef(ast::Name),
     EnumVariant(ast::Name),
-    Field(Option<ast::Name>),
+    Field(ast::Name),
     StructCtor, // implicit ctor for a tuple-like struct
     Initializer, // initializer for a const
     Binding(ast::Name), // pattern binding
@@ -185,14 +185,10 @@ pub fn as_interned_str(&self) -> InternedString {
             EnumVariant(name) |
             DetachedCrate(name) |
             Binding(name) |
-            Field(Some(name)) => {
+            Field(name) => {
                 name.as_str()
             }
 
-            Field(None) => {
-                InternedString::new("{{field}}")
-            }
-
             // note that this does not show up in user printouts
             CrateRoot => {
                 InternedString::new("{{root}}")

src/librustc/middle/dead.rs

@@ -429,13 +429,12 @@ fn should_warn_about_item(&mut self, item: &hir::Item) -> bool {
     }
 
     fn should_warn_about_field(&mut self, node: &hir::StructField_) -> bool {
-        let is_named = node.name.is_some();
         let field_type = self.tcx.node_id_to_type(node.id);
         let is_marker_field = match field_type.ty_to_def_id() {
             Some(def_id) => self.tcx.lang_items.items().iter().any(|item| *item == Some(def_id)),
             _ => false
         };
-        is_named
+        !node.is_positional()
             && !self.symbol_is_live(node.id, None)
             && !is_marker_field
             && !has_allow_dead_code_or_lang_attr(&node.attrs)
@@ -546,7 +545,7 @@ fn visit_foreign_item(&mut self, fi: &hir::ForeignItem) {
     fn visit_struct_field(&mut self, field: &hir::StructField) {
         if self.should_warn_about_field(&field.node) {
             self.warn_dead_code(field.node.id, field.span,
-                                field.node.name.unwrap(), "struct field");
+                                field.node.name, "struct field");
         }
 
         intravisit::walk_struct_field(self, field);

src/librustc/middle/ty/mod.rs

@@ -1371,8 +1371,6 @@ pub struct FieldDefData<'tcx, 'container: 'tcx> {
     /// The field's DefId. NOTE: the fields of tuple-like enum variants
     /// are not real items, and don't have entries in tcache etc.
     pub did: DefId,
-    /// special_idents::unnamed_field.name
-    /// if this is a tuple-like field
     pub name: Name,
     pub vis: hir::Visibility,
     /// TyIVar is used here to allow for variance (see the doc at

src/librustc_front/hir.rs

@@ -1242,45 +1242,22 @@ pub fn inherit_from(&self, parent_visibility: Visibility) -> Visibility {
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct StructField_ {
-    pub name: Option<Name>,
+    pub name: Name,
     pub vis: Visibility,
     pub id: NodeId,
     pub ty: P<Ty>,
     pub attrs: HirVec<Attribute>,
 }
 
-// impl StructField_ {
-//     pub fn name(&self) -> Option<Name> {
-//         match self.kind {
-//             NamedField(name, _) => Some(name),
-//             UnnamedField(_) => None,
-//         }
-//     }
-// }
-
 pub type StructField = Spanned<StructField_>;
 
-// #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug, Copy)]
-// pub enum StructFieldKind {
-//     NamedField(Name, Visibility),
-//     /// Element of a tuple-like struct
-//     UnnamedField(Visibility),
-// }
-
-// impl StructFieldKind {
-//     pub fn is_unnamed(&self) -> bool {
-//         match *self {
-//             UnnamedField(..) => true,
-//             NamedField(..) => false,
-//         }
-//     }
-
-//     pub fn visibility(&self) -> Visibility {
-//         match *self {
-//             NamedField(_, vis) | UnnamedField(vis) => vis,
-//         }
-//     }
-// }
+impl StructField_ {
+    // Still necessary in couple of places
+    pub fn is_positional(&self) -> bool {
+        let first = self.name.as_str().as_bytes()[0];
+        first >= b'0' && first <= b'9'
+    }
+}
 
 /// Fields and Ids of enum variants and structs
 ///

src/librustc_front/intravisit.rs

@@ -669,7 +669,7 @@ pub fn walk_struct_def<'v, V: Visitor<'v>>(visitor: &mut V, struct_definition: &
 }
 
 pub fn walk_struct_field<'v, V: Visitor<'v>>(visitor: &mut V, struct_field: &'v StructField) {
-    walk_opt_name(visitor, struct_field.span, struct_field.node.name);
+    visitor.visit_name(struct_field.span, struct_field.node.name);
     visitor.visit_ty(&struct_field.node.ty);
     walk_list!(visitor, visit_attribute, &struct_field.node.attrs);
 }

src/librustc_front/lowering.rs

@@ -578,12 +578,14 @@ pub fn lower_variant_data(lctx: &LoweringContext, vdata: &VariantData) -> hir::V
     match *vdata {
         VariantData::Struct(ref fields, id) => {
             hir::VariantData::Struct(fields.iter()
+                                           .enumerate()
                                            .map(|f| lower_struct_field(lctx, f))
                                            .collect(),
                                      id)
         }
         VariantData::Tuple(ref fields, id) => {
             hir::VariantData::Tuple(fields.iter()
+                                          .enumerate()
                                           .map(|f| lower_struct_field(lctx, f))
                                           .collect(),
                                     id)
@@ -607,11 +609,14 @@ pub fn lower_poly_trait_ref(lctx: &LoweringContext, p: &PolyTraitRef) -> hir::Po
     }
 }
 
-pub fn lower_struct_field(lctx: &LoweringContext, f: &StructField) -> hir::StructField {
+pub fn lower_struct_field(lctx: &LoweringContext,
+                          (index, f): (usize, &StructField))
+                          -> hir::StructField {
     Spanned {
         node: hir::StructField_ {
             id: f.node.id,
-            name: f.node.ident().map(|ident| ident.name),
+            name: f.node.ident().map(|ident| ident.name)
+                                .unwrap_or(token::intern(&index.to_string())),
             vis: lower_visibility(lctx, f.node.kind.visibility()),
             ty: lower_ty(lctx, &f.node.ty),
             attrs: lower_attrs(lctx, &f.node.attrs),

src/librustc_front/print/pprust.rs

@@ -938,7 +938,7 @@ pub fn print_struct(&mut self,
                 try!(self.maybe_print_comment(field.span.lo));
                 try!(self.print_outer_attributes(&field.node.attrs));
                 try!(self.print_visibility(field.node.vis));
-                try!(self.print_name(field.node.name.unwrap()));
+                try!(self.print_name(field.node.name));
                 try!(self.word_nbsp(":"));
                 try!(self.print_type(&field.node.ty));
                 try!(word(&mut self.s, ","));

src/librustc_lint/bad_style.rs

@@ -283,10 +283,7 @@ fn check_pat(&mut self, cx: &LateContext, p: &hir::Pat) {
     fn check_struct_def(&mut self, cx: &LateContext, s: &hir::VariantData,
                         _: ast::Name, _: &hir::Generics, _: ast::NodeId) {
         for sf in s.fields() {
-            if let Some(name) = sf.node.name {
-                self.check_snake_case(cx, "structure field", &name.as_str(),
-                                      Some(sf.span));
-            }
+            self.check_snake_case(cx, "structure field", &sf.node.name.as_str(), Some(sf.span));
         }
     }
 }

src/librustc_lint/builtin.rs

@@ -428,7 +428,7 @@ fn check_impl_item(&mut self, cx: &LateContext, impl_item: &hir::ImplItem) {
     }
 
     fn check_struct_field(&mut self, cx: &LateContext, sf: &hir::StructField) {
-        if sf.node.name.is_some() {
+        if !sf.node.is_positional() {
             if sf.node.vis == hir::Public || self.in_variant {
                 let cur_struct_def = *self.struct_def_stack.last()
                     .expect("empty struct_def_stack");

src/librustc_metadata/decoder.rs

@@ -48,8 +48,7 @@
 use rbml;
 use serialize::Decodable;
 use syntax::attr;
-use syntax::parse::token::{IdentInterner, special_idents};
-use syntax::parse::token;
+use syntax::parse::token::{self, IdentInterner};
 use syntax::ast;
 use syntax::abi::Abi;
 use syntax::codemap::{self, Span, BytePos, NO_EXPANSION};
@@ -406,6 +405,7 @@ fn get_variant_fields<'tcx>(intr: &IdentInterner,
                                 cdata: Cmd,
                                 doc: rbml::Doc,
                                 tcx: &ty::ctxt<'tcx>) -> Vec<ty::FieldDefData<'tcx, 'tcx>> {
+        let mut index = 0;
         reader::tagged_docs(doc, tag_item_field).map(|f| {
             let ff = item_family(f);
             match ff {
@@ -417,8 +417,9 @@ fn get_variant_fields<'tcx>(intr: &IdentInterner,
                                   struct_field_family_to_visibility(ff))
         }).chain(reader::tagged_docs(doc, tag_item_unnamed_field).map(|f| {
             let ff = item_family(f);
-            ty::FieldDefData::new(item_def_id(f, cdata),
-                                  special_idents::unnamed_field.name,
+            let name = intr.intern(&index.to_string());
+            index += 1;
+            ty::FieldDefData::new(item_def_id(f, cdata), name,
                                   struct_field_family_to_visibility(ff))
         })).collect()
     }
@@ -1153,10 +1154,13 @@ fn struct_field_family_to_visibility(family: Family) -> hir::Visibility {
 pub fn get_struct_field_names(intr: &IdentInterner, cdata: Cmd, id: DefIndex)
     -> Vec<ast::Name> {
     let item = cdata.lookup_item(id);
+    let mut index = 0;
     reader::tagged_docs(item, tag_item_field).map(|an_item| {
         item_name(intr, an_item)
     }).chain(reader::tagged_docs(item, tag_item_unnamed_field).map(|_| {
-        special_idents::unnamed_field.name
+        let name = intr.intern(&index.to_string());
+        index += 1;
+        name
     })).collect()
 }
 

src/librustc_metadata/encoder.rs

@@ -46,7 +46,6 @@
 use syntax::attr;
 use syntax::attr::AttrMetaMethods;
 use syntax::errors::Handler;
-use syntax::parse::token::special_idents;
 use syntax;
 use rbml::writer::Encoder;
 
@@ -249,7 +248,7 @@ fn encode_parent_item(rbml_w: &mut Encoder, id: DefId) {
 fn encode_struct_fields(rbml_w: &mut Encoder,
                         variant: ty::VariantDef) {
     for f in &variant.fields {
-        if f.name == special_idents::unnamed_field.name {
+        if variant.is_tuple_struct() {
             rbml_w.start_tag(tag_item_unnamed_field);
         } else {
             rbml_w.start_tag(tag_item_field);

src/librustc_resolve/build_reduced_graph.rs

@@ -380,12 +380,12 @@ fn build_reduced_graph_for_item(&mut self, item: &Item, parent: Module<'b>) -> M
                 }
 
                 // Record the def ID and fields of this struct.
-                let named_fields = struct_def.fields()
-                                             .iter()
-                                             .filter_map(|f| f.node.name)
-                                             .collect();
+                let field_names = struct_def.fields()
+                                            .iter()
+                                            .map(|f| f.node.name)
+                                            .collect();
                 let item_def_id = self.ast_map.local_def_id(item.id);
-                self.structs.insert(item_def_id, named_fields);
+                self.structs.insert(item_def_id, field_names);
 
                 parent
             }

src/librustc_typeck/check/dropck.rs

@@ -21,7 +21,6 @@
 
 use syntax::ast;
 use syntax::codemap::{self, Span};
-use syntax::parse::token::special_idents;
 
 /// check_drop_impl confirms that the Drop implementation identfied by
 /// `drop_impl_did` is not any more specialized than the type it is
@@ -299,7 +298,7 @@ pub fn check_safety_of_destructor_if_necessary<'a, 'tcx>(rcx: &mut Rcx<'a, 'tcx>
                     // no need for an additional note if the overflow
                     // was somehow on the root.
                 }
-                TypeContext::ADT { def_id, variant, field, field_index } => {
+                TypeContext::ADT { def_id, variant, field } => {
                     let adt = tcx.lookup_adt_def(def_id);
                     let variant_name = match adt.adt_kind() {
                         ty::AdtKind::Enum => format!("enum {} variant {}",
@@ -308,17 +307,12 @@ pub fn check_safety_of_destructor_if_necessary<'a, 'tcx>(rcx: &mut Rcx<'a, 'tcx>
                         ty::AdtKind::Struct => format!("struct {}",
                                                        tcx.item_path_str(def_id))
                     };
-                    let field_name = if field == special_idents::unnamed_field.name {
-                        format!("#{}", field_index)
-                    } else {
-                        format!("`{}`", field)
-                    };
                     span_note!(
                         &mut err,
                         span,
                         "overflowed on {} field {} type: {}",
                         variant_name,
-                        field_name,
+                        field,
                         detected_on_typ);
                 }
             }
@@ -338,7 +332,6 @@ enum TypeContext {
         def_id: DefId,
         variant: ast::Name,
         field: ast::Name,
-        field_index: usize
     }
 }
 
@@ -452,7 +445,7 @@ fn iterate_over_potentially_unsafe_regions_in_type<'a, 'b, 'tcx>(
         ty::TyStruct(def, substs) | ty::TyEnum(def, substs) => {
             let did = def.did;
             for variant in &def.variants {
-                for (i, field) in variant.fields.iter().enumerate() {
+                for field in variant.fields.iter() {
                     let fty = field.ty(tcx, substs);
                     let fty = cx.rcx.fcx.resolve_type_vars_if_possible(
                         cx.rcx.fcx.normalize_associated_types_in(cx.span, &fty));
@@ -462,7 +455,6 @@ fn iterate_over_potentially_unsafe_regions_in_type<'a, 'b, 'tcx>(
                             def_id: did,
                             field: field.name,
                             variant: variant.name,
-                            field_index: i
                         },
                         fty,
                         depth+1))

src/librustc_typeck/coherence/mod.rs

@@ -36,7 +36,6 @@
 use std::cell::RefCell;
 use std::rc::Rc;
 use syntax::codemap::Span;
-use syntax::parse::token;
 use util::nodemap::{DefIdMap, FnvHashMap};
 use rustc::dep_graph::DepNode;
 use rustc::front::map as hir_map;
@@ -449,13 +448,7 @@ fn check_implementations_of_coerce_unsized(&self) {
                                    for a coercion between structures with one field \
                                    being coerced, but {} fields need coercions: {}",
                                    diff_fields.len(), diff_fields.iter().map(|&(i, a, b)| {
-                                        let name = fields[i].name;
-                                        format!("{} ({} to {})",
-                                                if name == token::special_names::unnamed_field {
-                                                    i.to_string()
-                                                } else {
-                                                    name.to_string()
-                                                }, a, b)
+                                        format!("{} ({} to {})", fields[i].name, a, b)
                                    }).collect::<Vec<_>>().join(", "));
                         return;
                     }

src/librustc_typeck/collect.rs

@@ -978,22 +978,18 @@ fn convert_struct_variant<'tcx>(tcx: &ty::ctxt<'tcx>,
     let mut seen_fields: FnvHashMap<ast::Name, Span> = FnvHashMap();
     let fields = def.fields().iter().map(|f| {
         let fid = tcx.map.local_def_id(f.node.id);
-        if let Some(name) = f.node.name {
-            let dup_span = seen_fields.get(&name).cloned();
-            if let Some(prev_span) = dup_span {
-                let mut err = struct_span_err!(tcx.sess, f.span, E0124,
-                                               "field `{}` is already declared",
-                                               name);
-                span_note!(&mut err, prev_span, "previously declared here");
-                err.emit();
-            } else {
-                seen_fields.insert(name, f.span);
-            }
-
-            ty::FieldDefData::new(fid, name, f.node.vis)
+        let dup_span = seen_fields.get(&f.node.name).cloned();
+        if let Some(prev_span) = dup_span {
+            let mut err = struct_span_err!(tcx.sess, f.span, E0124,
+                                           "field `{}` is already declared",
+                                           f.node.name);
+            span_note!(&mut err, prev_span, "previously declared here");
+            err.emit();
         } else {
-            ty::FieldDefData::new(fid, special_idents::unnamed_field.name, f.node.vis)
+            seen_fields.insert(f.node.name, f.span);
         }
+
+        ty::FieldDefData::new(fid, f.node.name, f.node.vis)
     }).collect();
     ty::VariantDefData {
         did: did,

src/librustdoc/clean/inline.rs

@@ -188,8 +188,6 @@ fn build_external_function(cx: &DocContext, tcx: &ty::ctxt, did: DefId) -> clean
 }
 
 fn build_struct(cx: &DocContext, tcx: &ty::ctxt, did: DefId) -> clean::Struct {
-    use syntax::parse::token::special_idents::unnamed_field;
-
     let t = tcx.lookup_item_type(did);
     let predicates = tcx.lookup_predicates(did);
     let variant = tcx.lookup_adt_def(did).struct_variant();
@@ -197,8 +195,8 @@ fn build_struct(cx: &DocContext, tcx: &ty::ctxt, did: DefId) -> clean::Struct {
     clean::Struct {
         struct_type: match &*variant.fields {
             [] => doctree::Unit,
-            [ref f] if f.name == unnamed_field.name => doctree::Newtype,
-            [ref f, ..] if f.name == unnamed_field.name => doctree::Tuple,
+            [_] if variant.kind == ty::VariantKind::Tuple => doctree::Newtype,
+            [..] if variant.kind == ty::VariantKind::Tuple => doctree::Tuple,
             _ => doctree::Plain,
         },
         generics: (&t.generics, &predicates, subst::TypeSpace).clean(cx),

src/librustdoc/clean/mod.rs

@@ -1735,15 +1735,12 @@ pub enum StructField {
 
 impl Clean<Item> for hir::StructField {
     fn clean(&self, cx: &DocContext) -> Item {
-        let (name, vis) = match self.node.kind {
-            hir::NamedField(id, vis) => (Some(id), vis),
-            hir::UnnamedField(vis) => (None, vis)
-        };
+        let name = if self.node.is_positional() { None } else { Some(self.node.name) };
         Item {
             name: name.clean(cx),
             attrs: self.node.attrs.clean(cx),
             source: self.span.clean(cx),
-            visibility: Some(vis),
+            visibility: Some(self.node.vis),
             stability: get_stability(cx, cx.map.local_def_id(self.node.id)),
             deprecation: get_deprecation(cx, cx.map.local_def_id(self.node.id)),
             def_id: cx.map.local_def_id(self.node.id),
@@ -1754,12 +1751,15 @@ fn clean(&self, cx: &DocContext) -> Item {
 
 impl<'tcx> Clean<Item> for ty::FieldDefData<'tcx, 'static> {
     fn clean(&self, cx: &DocContext) -> Item {
-        use syntax::parse::token::special_idents::unnamed_field;
         // FIXME: possible O(n^2)-ness! Not my fault.
         let attr_map =
             cx.tcx().sess.cstore.crate_struct_field_attrs(self.did.krate);
 
-        let (name, attrs) = if self.name == unnamed_field.name {
+        let is_positional = {
+            let first = self.name.as_str().as_bytes()[0];
+            first >= b'0' && first <= b'9'
+        };
+        let (name, attrs) = if is_positional {
             (None, None)
         } else {
             (Some(self.name), Some(attr_map.get(&self.did).unwrap()))
@@ -1884,7 +1884,6 @@ fn clean(&self, cx: &DocContext) -> Item {
 
 impl<'tcx> Clean<Item> for ty::VariantDefData<'tcx, 'static> {
     fn clean(&self, cx: &DocContext) -> Item {
-        // use syntax::parse::token::special_idents::unnamed_field;
         let kind = match self.kind() {
             ty::VariantKind::Unit => CLikeVariant,
             ty::VariantKind::Tuple => {

src/libsyntax/parse/token.rs

@@ -542,7 +542,7 @@ pub mod special_idents {
         // outside of libsyntax
         (7,                          clownshoe_abi,          "__rust_abi");
         (8,                          opaque,                 "<opaque>");
-        (9,                          unnamed_field,          "<unnamed_field>");
+        (9,                          __unused1,              "<__unused1>");
         (super::SELF_TYPE_KEYWORD_NAME_NUM, type_self,       "Self");
         (11,                         prelude_import,         "prelude_import");
     }