diff --git a/src/librustc/back/link.rs b/src/librustc/back/link.rs
index 9a27c293e48..8f72d302bef 100644
--- a/src/librustc/back/link.rs
+++ b/src/librustc/back/link.rs
@@ -734,7 +734,7 @@ pub fn mangle_internal_name_by_path(ccx: @CrateContext, path: path) -> ~str {
 }
 
 pub fn mangle_internal_name_by_seq(ccx: @CrateContext, flav: &str) -> ~str {
-    return fmt!("%s_%u", flav, (ccx.names)(flav).repr);
+    return fmt!("%s_%u", flav, (ccx.names)(flav).name);
 }
 
 
diff --git a/src/librustc/driver/driver.rs b/src/librustc/driver/driver.rs
index 57d19e3ee16..928f7d5a791 100644
--- a/src/librustc/driver/driver.rs
+++ b/src/librustc/driver/driver.rs
@@ -39,6 +39,7 @@ use syntax::attr;
 use syntax::codemap;
 use syntax::diagnostic;
 use syntax::parse;
+use syntax::parse::token;
 use syntax::print::{pp, pprust};
 use syntax;
 
@@ -230,7 +231,7 @@ pub fn compile_rest(sess: Session,
                               sess.filesearch,
                               session::sess_os_to_meta_os(sess.targ_cfg.os),
                               sess.opts.is_static,
-                              sess.parse_sess.interner));
+                              token::get_ident_interner()));
 
     let lang_items = time(time_passes, ~"language item collection", ||
                           middle::lang_items::collect_language_items(crate, sess));
@@ -455,7 +456,7 @@ pub fn pretty_print_input(sess: Session, cfg: ast::crate_cfg, input: &input,
     let is_expanded = upto != cu_parse;
     let src = sess.codemap.get_filemap(source_name(input)).src;
     do io::with_str_reader(*src) |rdr| {
-        pprust::print_crate(sess.codemap, sess.parse_sess.interner,
+        pprust::print_crate(sess.codemap, token::get_ident_interner(),
                             sess.span_diagnostic, crate.unwrap(),
                             source_name(input),
                             rdr, io::stdout(), ann, is_expanded);
@@ -754,7 +755,7 @@ pub fn build_session_(sopts: @session::options,
     let target_cfg = build_target_config(sopts, demitter);
     let p_s = parse::new_parse_sess_special_handler(span_diagnostic_handler,
                                                     cm);
-    let cstore = @mut cstore::mk_cstore(p_s.interner);
+    let cstore = @mut cstore::mk_cstore(token::get_ident_interner());
     let filesearch = filesearch::mk_filesearch(
         &sopts.maybe_sysroot,
         sopts.target_triple,
@@ -963,7 +964,7 @@ pub fn early_error(emitter: diagnostic::Emitter, msg: ~str) -> ! {
 
 pub fn list_metadata(sess: Session, path: &Path, out: @io::Writer) {
     metadata::loader::list_file_metadata(
-        sess.parse_sess.interner,
+        token::get_ident_interner(),
         session::sess_os_to_meta_os(sess.targ_cfg.os), path, out);
 }
 
diff --git a/src/librustc/driver/session.rs b/src/librustc/driver/session.rs
index d6a99b3edc9..211665942a8 100644
--- a/src/librustc/driver/session.rs
+++ b/src/librustc/driver/session.rs
@@ -26,6 +26,7 @@ use syntax::diagnostic;
 use syntax::parse::ParseSess;
 use syntax::{ast, codemap};
 use syntax::abi;
+use syntax::parse::token;
 use syntax;
 
 use core::hashmap::HashMap;
@@ -293,14 +294,19 @@ impl Session_ {
         self.opts.optimize == No && !self.debugging_opt(no_debug_borrows)
     }
 
+    // pointless function, now...
     pub fn str_of(@self, id: ast::ident) -> @~str {
-        self.parse_sess.interner.get(id)
+        token::ident_to_str(&id)
     }
+
+    // pointless function, now...
     pub fn ident_of(@self, st: &str) -> ast::ident {
-        self.parse_sess.interner.intern(st)
+        token::str_to_ident(st)
     }
+
+    // pointless function, now...
     pub fn intr(@self) -> @syntax::parse::token::ident_interner {
-        self.parse_sess.interner
+        token::get_ident_interner()
     }
 }
 
diff --git a/src/librustc/front/test.rs b/src/librustc/front/test.rs
index 8cd8a989352..cda7d1fa937 100644
--- a/src/librustc/front/test.rs
+++ b/src/librustc/front/test.rs
@@ -22,6 +22,7 @@ use syntax::codemap::{dummy_sp, span, ExpandedFrom, CallInfo, NameAndSpan};
 use syntax::codemap;
 use syntax::ext::base::ExtCtxt;
 use syntax::fold;
+use syntax::parse::token;
 use syntax::print::pprust;
 use syntax::{ast, ast_util};
 
@@ -143,7 +144,7 @@ fn fold_item(cx: @mut TestCtxt, i: @ast::item, fld: @fold::ast_fold)
           -> Option<@ast::item> {
     cx.path.push(i.ident);
     debug!("current path: %s",
-           ast_util::path_name_i(copy cx.path, cx.sess.parse_sess.interner));
+           ast_util::path_name_i(copy cx.path));
 
     if is_test_fn(cx, i) || is_bench_fn(i) {
         match i.node {
@@ -411,13 +412,10 @@ fn mk_test_desc_and_fn_rec(cx: &TestCtxt, test: &Test) -> @ast::expr {
 
     let ext_cx = cx.ext_cx;
 
-    debug!("encoding %s", ast_util::path_name_i(path,
-                                                cx.sess.parse_sess.interner));
+    debug!("encoding %s", ast_util::path_name_i(path));
 
     let name_lit: ast::lit =
-        nospan(ast::lit_str(@ast_util::path_name_i(
-            path,
-            cx.sess.parse_sess.interner)));
+        nospan(ast::lit_str(@ast_util::path_name_i(path)));
 
     let name_expr = @ast::expr {
           id: cx.sess.next_node_id(),
diff --git a/src/librustc/metadata/creader.rs b/src/librustc/metadata/creader.rs
index 0e263c78bfe..546c516c287 100644
--- a/src/librustc/metadata/creader.rs
+++ b/src/librustc/metadata/creader.rs
@@ -22,6 +22,7 @@ use core::vec;
 use syntax::attr;
 use syntax::codemap::{span, dummy_sp};
 use syntax::diagnostic::span_handler;
+use syntax::parse::token;
 use syntax::parse::token::ident_interner;
 use syntax::visit;
 use syntax::ast;
@@ -176,7 +177,7 @@ fn visit_item(e: @mut Env, i: @ast::item) {
                             }
                             nn
                         }
-                        None => e.intr.get(i.ident)
+                        None => token::ident_to_str(&i.ident)
                     };
                 if attr::find_attrs_by_name(i.attrs, "nolink").is_empty() {
                     already_added =
@@ -235,7 +236,7 @@ fn resolve_crate(e: @mut Env,
                  hash: @~str,
                  span: span)
               -> ast::crate_num {
-    let metas = metas_with_ident(@/*bad*/copy *e.intr.get(ident), metas);
+    let metas = metas_with_ident(token::ident_to_str(&ident), metas);
 
     match existing_match(e, metas, hash) {
       None => {
@@ -276,7 +277,7 @@ fn resolve_crate(e: @mut Env,
             match attr::last_meta_item_value_str_by_name(load_ctxt.metas,
                                                          "name") {
                 Some(v) => v,
-                None => e.intr.get(ident),
+                None => token::ident_to_str(&ident),
             };
         let cmeta = @cstore::crate_metadata {
             name: cname,
@@ -305,10 +306,11 @@ fn resolve_crate_deps(e: @mut Env, cdata: @~[u8]) -> cstore::cnum_map {
     for decoder::get_crate_deps(e.intr, cdata).each |dep| {
         let extrn_cnum = dep.cnum;
         let cname = dep.name;
+        let cname_str = token::ident_to_str(&dep.name);
         let cmetas = metas_with(dep.vers, @~"vers", ~[]);
         debug!("resolving dep crate %s ver: %s hash: %s",
-               *e.intr.get(dep.name), *dep.vers, *dep.hash);
-        match existing_match(e, metas_with_ident(e.intr.get(cname),
+               *cname_str, *dep.vers, *dep.hash);
+        match existing_match(e, metas_with_ident(cname_str,
                                                  copy cmetas),
                              dep.hash) {
           Some(local_cnum) => {
diff --git a/src/librustc/metadata/decoder.rs b/src/librustc/metadata/decoder.rs
index bb35af19807..baf93416379 100644
--- a/src/librustc/metadata/decoder.rs
+++ b/src/librustc/metadata/decoder.rs
@@ -40,6 +40,7 @@ use syntax::parse::token::{StringRef, ident_interner, special_idents};
 use syntax::print::pprust;
 use syntax::{ast, ast_util};
 use syntax::codemap;
+use syntax::parse::token;
 
 type cmd = @crate_metadata;
 
@@ -297,10 +298,10 @@ fn item_path(intr: @ident_interner, item_doc: ebml::Doc) -> ast_map::path {
     for reader::docs(path_doc) |tag, elt_doc| {
         if tag == tag_path_elt_mod {
             let str = reader::doc_as_str(elt_doc);
-            result.push(ast_map::path_mod(intr.intern(str)));
+            result.push(ast_map::path_mod(token::str_to_ident(str)));
         } else if tag == tag_path_elt_name {
             let str = reader::doc_as_str(elt_doc);
-            result.push(ast_map::path_name(intr.intern(str)));
+            result.push(ast_map::path_name(token::str_to_ident(str)));
         } else {
             // ignore tag_path_len element
         }
@@ -314,8 +315,8 @@ fn item_name(intr: @ident_interner, item: ebml::Doc) -> ast::ident {
     do reader::with_doc_data(name) |data| {
         let string = str::from_bytes_slice(data);
         match intr.find_equiv(&StringRef(string)) {
-            None => intr.intern(string),
-            Some(val) => val,
+            None => token::str_to_ident(string),
+            Some(val) => ast::new_ident(val),
         }
     }
 }
@@ -843,7 +844,7 @@ pub fn get_type_name_if_impl(intr: @ident_interner,
     }
 
     for reader::tagged_docs(item, tag_item_impl_type_basename) |doc| {
-        return Some(intr.intern(str::from_bytes(reader::doc_data(doc))));
+        return Some(token::str_to_ident(str::from_bytes(reader::doc_data(doc))));
     }
 
     return None;
@@ -1095,7 +1096,7 @@ pub fn get_crate_deps(intr: @ident_interner, data: @~[u8]) -> ~[crate_dep] {
     }
     for reader::tagged_docs(depsdoc, tag_crate_dep) |depdoc| {
         deps.push(crate_dep {cnum: crate_num,
-                  name: intr.intern(docstr(depdoc, tag_crate_dep_name)),
+                  name: token::str_to_ident(docstr(depdoc, tag_crate_dep_name)),
                   vers: @docstr(depdoc, tag_crate_dep_vers),
                   hash: @docstr(depdoc, tag_crate_dep_hash)});
         crate_num += 1;
@@ -1109,7 +1110,7 @@ fn list_crate_deps(intr: @ident_interner, data: @~[u8], out: @io::Writer) {
     for get_crate_deps(intr, data).each |dep| {
         out.write_str(
             fmt!("%d %s-%s-%s\n",
-                 dep.cnum, *intr.get(dep.name), *dep.hash, *dep.vers));
+                 dep.cnum, *token::ident_to_str(&dep.name), *dep.hash, *dep.vers));
     }
 
     out.write_str("\n");
diff --git a/src/librustc/metadata/encoder.rs b/src/librustc/metadata/encoder.rs
index 6f453a79b68..2365897c4d7 100644
--- a/src/librustc/metadata/encoder.rs
+++ b/src/librustc/metadata/encoder.rs
@@ -43,6 +43,7 @@ use syntax::opt_vec::OptVec;
 use syntax::opt_vec;
 use syntax::parse::token::special_idents;
 use syntax::{ast_util, visit};
+use syntax::parse::token;
 use syntax;
 use writer = extra::ebml::writer;
 
@@ -141,8 +142,7 @@ fn add_to_index(ecx: @EncodeContext,
     full_path.push(name);
     index.push(
         entry {
-            val: ast_util::path_name_i(full_path,
-                                       ecx.tcx.sess.parse_sess.interner),
+            val: ast_util::path_name_i(full_path),
             pos: ebml_w.writer.tell()
         });
 }
@@ -485,8 +485,7 @@ fn encode_info_for_mod(ecx: @EncodeContext,
                         (%?/%?)",
                         *ecx.tcx.sess.str_of(ident),
                         did,
-                        ast_map::node_id_to_str(ecx.tcx.items, did, ecx.tcx
-                                                .sess.parse_sess.interner));
+                        ast_map::node_id_to_str(ecx.tcx.items, did, token::get_ident_interner()));
 
                 ebml_w.start_tag(tag_mod_impl);
                 ebml_w.wr_str(def_to_str(local_def(did)));
@@ -1055,7 +1054,7 @@ fn encode_info_for_item(ecx: @EncodeContext,
                         tcx.sess.span_unimpl(
                             item.span,
                             fmt!("Method %s is both provided and static",
-                                 *tcx.sess.intr().get(method_ty.ident)));
+                                 *token::ident_to_str(&method_ty.ident)));
                     }
                     encode_type_param_bounds(ebml_w, ecx,
                                              &m.generics.ty_params);
diff --git a/src/librustc/metadata/loader.rs b/src/librustc/metadata/loader.rs
index 182f1e9078c..1ebf8f2e9f4 100644
--- a/src/librustc/metadata/loader.rs
+++ b/src/librustc/metadata/loader.rs
@@ -19,6 +19,7 @@ use metadata::filesearch::FileSearch;
 use metadata::filesearch;
 use syntax::codemap::span;
 use syntax::diagnostic::span_handler;
+use syntax::parse::token;
 use syntax::parse::token::ident_interner;
 use syntax::print::pprust;
 use syntax::{ast, attr};
@@ -59,7 +60,7 @@ pub fn load_library_crate(cx: &Context) -> (~str, @~[u8]) {
       None => {
         cx.diag.span_fatal(
             cx.span, fmt!("can't find crate for `%s`",
-                          *cx.intr.get(cx.ident)));
+                          *token::ident_to_str(&cx.ident)));
       }
     }
 }
diff --git a/src/librustc/middle/astencode.rs b/src/librustc/middle/astencode.rs
index c26e91cc5ec..8bde4e37d54 100644
--- a/src/librustc/middle/astencode.rs
+++ b/src/librustc/middle/astencode.rs
@@ -41,6 +41,7 @@ use syntax::codemap::span;
 use syntax::codemap;
 use syntax::fold::*;
 use syntax::fold;
+use syntax::parse::token;
 use syntax;
 use writer = extra::ebml::writer;
 
@@ -86,7 +87,7 @@ pub fn encode_inlined_item(ecx: @e::EncodeContext,
                            ii: ast::inlined_item,
                            maps: Maps) {
     debug!("> Encoding inlined item: %s::%s (%u)",
-           ast_map::path_to_str(path, ecx.tcx.sess.parse_sess.interner),
+           ast_map::path_to_str(path, token::get_ident_interner()),
            *ecx.tcx.sess.str_of(ii.ident()),
            ebml_w.writer.tell());
 
@@ -99,7 +100,7 @@ pub fn encode_inlined_item(ecx: @e::EncodeContext,
     ebml_w.end_tag();
 
     debug!("< Encoded inlined fn: %s::%s (%u)",
-           ast_map::path_to_str(path, ecx.tcx.sess.parse_sess.interner),
+           ast_map::path_to_str(path, token::get_ident_interner()),
            *ecx.tcx.sess.str_of(ii.ident()),
            ebml_w.writer.tell());
 }
@@ -119,7 +120,7 @@ pub fn decode_inlined_item(cdata: @cstore::crate_metadata,
       None => None,
       Some(ast_doc) => {
         debug!("> Decoding inlined fn: %s::?",
-               ast_map::path_to_str(path, tcx.sess.parse_sess.interner));
+               ast_map::path_to_str(path, token::get_ident_interner()));
         let mut ast_dsr = reader::Decoder(ast_doc);
         let from_id_range = Decodable::decode(&mut ast_dsr);
         let to_id_range = reserve_id_range(dcx.tcx.sess, from_id_range);
@@ -132,7 +133,7 @@ pub fn decode_inlined_item(cdata: @cstore::crate_metadata,
         let ii = renumber_ast(xcx, raw_ii);
         debug!("Fn named: %s", *tcx.sess.str_of(ii.ident()));
         debug!("< Decoded inlined fn: %s::%s",
-               ast_map::path_to_str(path, tcx.sess.parse_sess.interner),
+               ast_map::path_to_str(path, token::get_ident_interner()),
                *tcx.sess.str_of(ii.ident()));
         ast_map::map_decoded_item(tcx.sess.diagnostic(),
                                   dcx.tcx.items, path, &ii);
@@ -1167,7 +1168,7 @@ impl fake_ext_ctxt for fake_session {
         }
     }
     fn ident_of(&self, st: &str) -> ast::ident {
-        self.interner.intern(st)
+        token::str_to_ident(st)
     }
 }
 
@@ -1236,9 +1237,9 @@ fn test_simplification() {
     match (item_out, item_exp) {
       (ast::ii_item(item_out), ast::ii_item(item_exp)) => {
         assert!(pprust::item_to_str(item_out,
-                                         ext_cx.parse_sess().interner)
+                                    token::get_ident_interner())
                      == pprust::item_to_str(item_exp,
-                                            ext_cx.parse_sess().interner));
+                                            token::get_ident_interner()));
       }
       _ => fail!()
     }
diff --git a/src/librustc/middle/borrowck/mod.rs b/src/librustc/middle/borrowck/mod.rs
index 0834d036083..fa3bae3f5ac 100644
--- a/src/librustc/middle/borrowck/mod.rs
+++ b/src/librustc/middle/borrowck/mod.rs
@@ -30,6 +30,7 @@ use syntax::ast;
 use syntax::ast_map;
 use syntax::visit;
 use syntax::codemap::span;
+use syntax::parse::token;
 
 macro_rules! if_ok(
     ($inp: expr) => (
@@ -710,8 +711,8 @@ impl BorrowckCtxt {
         match *loan_path {
             LpVar(id) => {
                 match self.tcx.items.find(&id) {
-                    Some(&ast_map::node_local(ident)) => {
-                        str::push_str(out, *self.tcx.sess.intr().get(ident));
+                    Some(&ast_map::node_local(ref ident)) => {
+                        str::push_str(out, *token::ident_to_str(ident));
                     }
                     r => {
                         self.tcx.sess.bug(
@@ -724,9 +725,9 @@ impl BorrowckCtxt {
             LpExtend(lp_base, _, LpInterior(mc::InteriorField(fname))) => {
                 self.append_loan_path_to_str_from_interior(lp_base, out);
                 match fname {
-                    mc::NamedField(fname) => {
+                    mc::NamedField(ref fname) => {
                         str::push_char(out, '.');
-                        str::push_str(out, *self.tcx.sess.intr().get(fname));
+                        str::push_str(out, *token::ident_to_str(fname));
                     }
                     mc::PositionalField(idx) => {
                         str::push_char(out, '#'); // invent a notation here
diff --git a/src/librustc/middle/privacy.rs b/src/librustc/middle/privacy.rs
index 1e596ee6b36..fe30b9c4fd7 100644
--- a/src/librustc/middle/privacy.rs
+++ b/src/librustc/middle/privacy.rs
@@ -35,6 +35,7 @@ use syntax::ast_util::{Private, Public, is_local};
 use syntax::ast_util::{variant_visibility_to_privacy, visibility_to_privacy};
 use syntax::attr;
 use syntax::codemap::span;
+use syntax::parse::token;
 use syntax::visit;
 
 pub fn check_crate(tcx: ty::ctxt,
@@ -120,7 +121,7 @@ pub fn check_crate(tcx: ty::ctxt,
                                        ast_map::node_id_to_str(
                                             tcx.items,
                                             method_id,
-                                            tcx.sess.parse_sess.interner)));
+                                           token::get_ident_interner())));
             }
             None => {
                 tcx.sess.span_bug(span, "method not found in \
@@ -184,7 +185,7 @@ pub fn check_crate(tcx: ty::ctxt,
                                        ast_map::node_id_to_str(
                                             tcx.items,
                                             method_id,
-                                            tcx.sess.parse_sess.interner)));
+                                           token::get_ident_interner())));
             }
             None => {
                 tcx.sess.span_bug(span, "method not found in \
@@ -216,9 +217,7 @@ pub fn check_crate(tcx: ty::ctxt,
                                            ast_map::node_id_to_str(
                                                 tcx.items,
                                                 item_id,
-                                                tcx.sess
-                                                   .parse_sess
-                                                   .interner)));
+                                               token::get_ident_interner())));
                 }
                 None => {
                     tcx.sess.span_bug(span, "item not found in AST map?!");
@@ -236,8 +235,7 @@ pub fn check_crate(tcx: ty::ctxt,
             if field.ident != ident { loop; }
             if field.vis == private {
                 tcx.sess.span_err(span, fmt!("field `%s` is private",
-                                             *tcx.sess.parse_sess.interner
-                                                 .get(ident)));
+                                             *token::ident_to_str(&ident)));
             }
             break;
         }
@@ -257,10 +255,7 @@ pub fn check_crate(tcx: ty::ctxt,
                      !privileged_items.contains(&(container_id.node))) {
                 tcx.sess.span_err(span,
                                   fmt!("method `%s` is private",
-                                       *tcx.sess
-                                           .parse_sess
-                                           .interner
-                                           .get(*name)));
+                                       *token::ident_to_str(name)));
             }
         } else {
             let visibility =
@@ -268,8 +263,7 @@ pub fn check_crate(tcx: ty::ctxt,
             if visibility != public {
                 tcx.sess.span_err(span,
                                   fmt!("method `%s` is private",
-                                       *tcx.sess.parse_sess.interner
-                                           .get(*name)));
+                                       *token::ident_to_str(name)));
             }
         }
     };
@@ -289,23 +283,13 @@ pub fn check_crate(tcx: ty::ctxt,
                             !privileged_items.contains(&def_id.node) {
                         tcx.sess.span_err(span,
                                           fmt!("function `%s` is private",
-                                               *tcx.sess
-                                                   .parse_sess
-                                                   .interner
-                                                   .get(copy *path
-                                                             .idents
-                                                             .last())));
+                                               *token::ident_to_str(path.idents.last())));
                     }
                 } else if csearch::get_item_visibility(tcx.sess.cstore,
                                                        def_id) != public {
                     tcx.sess.span_err(span,
                                       fmt!("function `%s` is private",
-                                           *tcx.sess
-                                               .parse_sess
-                                               .interner
-                                               .get(copy *path
-                                                         .idents
-                                                         .last())));
+                                           *token::ident_to_str(path.idents.last())));
                 }
             }
             _ => {}
@@ -335,10 +319,7 @@ pub fn check_crate(tcx: ty::ctxt,
                             match item.node {
                                 item_trait(_, _, ref methods) => {
                                     if method_num >= (*methods).len() {
-                                        tcx.sess.span_bug(span, "method \
-                                                                 number \
-                                                                 out of \
-                                                                 range?!");
+                                        tcx.sess.span_bug(span, "method number out of range?!");
                                     }
                                     match (*methods)[method_num] {
                                         provided(method)
@@ -346,17 +327,9 @@ pub fn check_crate(tcx: ty::ctxt,
                                              !privileged_items
                                              .contains(&(trait_id.node)) => {
                                             tcx.sess.span_err(span,
-                                                              fmt!("method
-                                                                    `%s` \
-                                                                    is \
-                                                                    private",
-                                                                   *tcx
-                                                                   .sess
-                                                                   .parse_sess
-                                                                   .interner
-                                                                   .get
-                                                                   (method
-                                                                    .ident)));
+                                                              fmt!("method `%s` is private",
+                                                                   *token::ident_to_str(&method
+                                                                                        .ident)));
                                         }
                                         provided(_) | required(_) => {
                                             // Required methods can't be
@@ -365,20 +338,15 @@ pub fn check_crate(tcx: ty::ctxt,
                                     }
                                 }
                                 _ => {
-                                    tcx.sess.span_bug(span, "trait wasn't \
-                                                             actually a \
-                                                             trait?!");
+                                    tcx.sess.span_bug(span, "trait wasn't actually a trait?!");
                                 }
                             }
                         }
                         Some(_) => {
-                            tcx.sess.span_bug(span, "trait wasn't an \
-                                                     item?!");
+                            tcx.sess.span_bug(span, "trait wasn't an item?!");
                         }
                         None => {
-                            tcx.sess.span_bug(span, "trait item wasn't \
-                                                     found in the AST \
-                                                     map?!");
+                            tcx.sess.span_bug(span, "trait item wasn't found in the AST map?!");
                         }
                     }
                 } else {
diff --git a/src/librustc/middle/region.rs b/src/librustc/middle/region.rs
index 5478d0900f9..5ccb38b960d 100644
--- a/src/librustc/middle/region.rs
+++ b/src/librustc/middle/region.rs
@@ -30,6 +30,7 @@ use core::hashmap::{HashMap, HashSet};
 use syntax::ast_map;
 use syntax::codemap::span;
 use syntax::print::pprust;
+use syntax::parse::token;
 use syntax::parse::token::special_idents;
 use syntax::{ast, visit};
 
@@ -595,7 +596,7 @@ impl DetermineRpCtxt {
 
         debug!("add_rp() variance for %s: %? == %? ^ %?",
                ast_map::node_id_to_str(self.ast_map, id,
-                                       self.sess.parse_sess.interner),
+                                       token::get_ident_interner()),
                joined_variance, old_variance, variance);
 
         if Some(joined_variance) != old_variance {
@@ -614,9 +615,9 @@ impl DetermineRpCtxt {
         debug!("add dependency from %d -> %d (%s -> %s) with variance %?",
                from, self.item_id,
                ast_map::node_id_to_str(self.ast_map, from,
-                                       self.sess.parse_sess.interner),
+                                       token::get_ident_interner()),
                ast_map::node_id_to_str(self.ast_map, self.item_id,
-                                       self.sess.parse_sess.interner),
+                                       token::get_ident_interner()),
                copy self.ambient_variance);
         let vec = match self.dep_map.find(&from) {
             Some(&vec) => vec,
@@ -951,7 +952,7 @@ pub fn determine_rp_in_crate(sess: Session,
             debug!("item %? (%s) is parameterized with variance %?",
                    key,
                    ast_map::node_id_to_str(ast_map, key,
-                                           sess.parse_sess.interner),
+                                           token::get_ident_interner()),
                    value);
         }
         "----"
diff --git a/src/librustc/middle/resolve.rs b/src/librustc/middle/resolve.rs
index db98407cc55..c23932b14b5 100644
--- a/src/librustc/middle/resolve.rs
+++ b/src/librustc/middle/resolve.rs
@@ -28,6 +28,7 @@ use syntax::ast_util::{path_to_ident, walk_pat, trait_method_to_ty_method};
 use syntax::ast_util::{Privacy, Public, Private};
 use syntax::ast_util::{variant_visibility_to_privacy, visibility_to_privacy};
 use syntax::attr::{attr_metas, contains_name};
+use syntax::parse::token;
 use syntax::parse::token::ident_interner;
 use syntax::parse::token::special_idents;
 use syntax::print::pprust::path_to_str;
@@ -727,7 +728,7 @@ impl PrimitiveTypeTable {
                   intr: @ident_interner,
                   string: &str,
                   primitive_type: prim_ty) {
-        let ident = intr.intern(string);
+        let ident = token::str_to_ident(string);
         self.primitive_types.insert(ident, primitive_type);
     }
 }
@@ -805,8 +806,7 @@ pub fn Resolver(session: Session,
         self_ident: special_idents::self_,
         type_self_ident: special_idents::type_self,
 
-        primitive_type_table: @PrimitiveTypeTable(session.
-                                                  parse_sess.interner),
+        primitive_type_table: @PrimitiveTypeTable(token::get_ident_interner()),
 
         namespaces: ~[ TypeNS, ValueNS ],
 
@@ -2942,17 +2942,17 @@ impl Resolver {
                                  module_: @mut Module,
                                  module_path: &[ident])
                                  -> ResolveResult<ModulePrefixResult> {
-        let interner = self.session.parse_sess.interner;
+        let interner = token::get_ident_interner();
 
         // Start at the current module if we see `self` or `super`, or at the
         // top of the crate otherwise.
         let mut containing_module;
         let mut i;
-        if *interner.get(module_path[0]) == ~"self" {
+        if *token::ident_to_str(&module_path[0]) == ~"self" {
             containing_module =
                 self.get_nearest_normal_module_parent_or_self(module_);
             i = 1;
-        } else if *interner.get(module_path[0]) == ~"super" {
+        } else if *token::ident_to_str(&module_path[0]) == ~"super" {
             containing_module =
                 self.get_nearest_normal_module_parent_or_self(module_);
             i = 0;  // We'll handle `super` below.
@@ -2962,7 +2962,7 @@ impl Resolver {
 
         // Now loop through all the `super`s we find.
         while i < module_path.len() &&
-                *interner.get(module_path[i]) == ~"super" {
+                *token::ident_to_str(&module_path[i]) == ~"super" {
             debug!("(resolving module prefix) resolving `super` at %s",
                    self.module_to_str(containing_module));
             match self.get_nearest_normal_module_parent(containing_module) {
diff --git a/src/librustc/middle/trans/base.rs b/src/librustc/middle/trans/base.rs
index c2dffa265ad..ba88fe09e70 100644
--- a/src/librustc/middle/trans/base.rs
+++ b/src/librustc/middle/trans/base.rs
@@ -78,7 +78,8 @@ use syntax::ast_map::{path, path_elt_to_str, path_name};
 use syntax::ast_util::{local_def, path_to_ident};
 use syntax::attr;
 use syntax::codemap::span;
-use syntax::parse::token::special_idents;
+use syntax::parse::token;
+use syntax::parse::token::{special_idents};
 use syntax::print::pprust::stmt_to_str;
 use syntax::visit;
 use syntax::{ast, ast_util, codemap, ast_map};
@@ -2257,10 +2258,10 @@ pub fn register_fn_fuller(ccx: @CrateContext,
                           -> ValueRef {
     debug!("register_fn_fuller creating fn for item %d with path %s",
            node_id,
-           ast_map::path_to_str(path, ccx.sess.parse_sess.interner));
+           ast_map::path_to_str(path, token::get_ident_interner()));
 
     let ps = if attr::attrs_contains_name(attrs, "no_mangle") {
-        path_elt_to_str(*path.last(), ccx.sess.parse_sess.interner)
+        path_elt_to_str(*path.last(), token::get_ident_interner())
     } else {
         mangle_exported_name(ccx, /*bad*/copy path, node_type)
     };
@@ -2504,7 +2505,7 @@ pub fn get_item_val(ccx: @CrateContext, id: ast::node_id) -> ValueRef {
                 }
                 ast::foreign_item_const(*) => {
                     let typ = ty::node_id_to_type(tcx, ni.id);
-                    let ident = ccx.sess.parse_sess.interner.get(ni.ident);
+                    let ident = token::ident_to_str(&ni.ident);
                     let g = do str::as_c_str(*ident) |buf| {
                         unsafe {
                             llvm::LLVMAddGlobal(ccx.llmod,
@@ -3069,7 +3070,7 @@ pub fn trans_crate(sess: session::Session,
         lib::llvm::associate_type(tn, @"tydesc", tydesc_type);
         let crate_map = decl_crate_map(sess, link_meta, llmod);
         let dbg_cx = if sess.opts.debuginfo {
-            Some(debuginfo::mk_ctxt(copy llmod_id, sess.parse_sess.interner))
+            Some(debuginfo::mk_ctxt(copy llmod_id, token::get_ident_interner()))
         } else {
             None
         };
@@ -3104,7 +3105,7 @@ pub fn trans_crate(sess: session::Session,
               lltypes: @mut HashMap::new(),
               llsizingtypes: @mut HashMap::new(),
               adt_reprs: @mut HashMap::new(),
-              names: new_namegen(sess.parse_sess.interner),
+              names: new_namegen(token::get_ident_interner()),
               next_addrspace: new_addrspace_gen(),
               symbol_hasher: symbol_hasher,
               type_hashcodes: @mut HashMap::new(),
diff --git a/src/librustc/middle/trans/common.rs b/src/librustc/middle/trans/common.rs
index a5e04832d69..8831cde1105 100644
--- a/src/librustc/middle/trans/common.rs
+++ b/src/librustc/middle/trans/common.rs
@@ -52,16 +52,19 @@ use core::vec;
 use syntax::ast::ident;
 use syntax::ast_map::{path, path_elt};
 use syntax::codemap::span;
+use syntax::parse::token;
 use syntax::parse::token::ident_interner;
 use syntax::{ast, ast_map};
 use syntax::abi::{X86, X86_64, Arm, Mips};
 
+// NOTE: this thunk is totally pointless now that we're not passing
+// interners around...
 pub type namegen = @fn(s: &str) -> ident;
 pub fn new_namegen(intr: @ident_interner) -> namegen {
     let f: @fn(s: &str) -> ident = |prefix| {
-        intr.gensym(fmt!("%s_%u",
-                          prefix,
-                          intr.gensym(prefix).repr))
+        token::str_to_ident(fmt!("%s_%u",
+                                 prefix,
+                                 token::gensym(prefix)))
     };
     f
 }
@@ -1195,7 +1198,7 @@ pub fn C_cstr(cx: @CrateContext, s: @~str) -> ValueRef {
             llvm::LLVMConstString(buf, s.len() as c_uint, False)
         };
         let g =
-            str::as_c_str(fmt!("str%u", (cx.names)("str").repr),
+            str::as_c_str(fmt!("str%u", (cx.names)("str").name),
                         |buf| llvm::LLVMAddGlobal(cx.llmod, val_ty(sc), buf));
         llvm::LLVMSetInitializer(g, sc);
         llvm::LLVMSetGlobalConstant(g, True);
@@ -1287,7 +1290,7 @@ pub fn C_bytes_plus_null(bytes: &[u8]) -> ValueRef {
 pub fn C_shape(ccx: @CrateContext, bytes: ~[u8]) -> ValueRef {
     unsafe {
         let llshape = C_bytes_plus_null(bytes);
-        let name = fmt!("shape%u", (ccx.names)("shape").repr);
+        let name = fmt!("shape%u", (ccx.names)("shape").name);
         let llglobal = str::as_c_str(name, |buf| {
             llvm::LLVMAddGlobal(ccx.llmod, val_ty(llshape), buf)
         });
diff --git a/src/librustc/middle/trans/foreign.rs b/src/librustc/middle/trans/foreign.rs
index 81ce0dcdad4..dfcf364233b 100644
--- a/src/librustc/middle/trans/foreign.rs
+++ b/src/librustc/middle/trans/foreign.rs
@@ -41,6 +41,7 @@ use syntax::{ast, ast_util};
 use syntax::{attr, ast_map};
 use syntax::opt_vec;
 use syntax::parse::token::special_idents;
+use syntax::parse::token;
 use syntax::abi::{X86, X86_64, Arm, Mips};
 use syntax::abi::{RustIntrinsic, Rust, Stdcall, Fastcall,
                   Cdecl, Aapcs, C};
@@ -343,8 +344,7 @@ pub fn trans_foreign_mod(ccx: @CrateContext,
                 }
             }
             ast::foreign_item_const(*) => {
-                let ident = ccx.sess.parse_sess.interner.get(
-                    foreign_item.ident);
+                let ident = token::ident_to_str(&foreign_item.ident);
                 ccx.item_symbols.insert(foreign_item.id, copy *ident);
             }
         }
diff --git a/src/librustc/middle/trans/type_use.rs b/src/librustc/middle/trans/type_use.rs
index 318612bd15b..9c84b4ffa99 100644
--- a/src/librustc/middle/trans/type_use.rs
+++ b/src/librustc/middle/trans/type_use.rs
@@ -42,6 +42,7 @@ use syntax::ast;
 use syntax::ast::*;
 use syntax::ast_map;
 use syntax::ast_util;
+use syntax::parse::token;
 use syntax::visit;
 
 pub type type_uses = uint; // Bitmask
@@ -170,7 +171,7 @@ pub fn type_uses_for(ccx: @CrateContext, fn_id: def_id, n_tps: uint)
                               ast_map::node_id_to_str(
                                 ccx.tcx.items,
                                 fn_id_loc.node,
-                                ccx.tcx.sess.parse_sess.interner)));
+                                token::get_ident_interner())));
       }
     }
     let Context { uses, _ } = cx;
diff --git a/src/librustc/middle/ty.rs b/src/librustc/middle/ty.rs
index 433c1a864dd..363af7c9e56 100644
--- a/src/librustc/middle/ty.rs
+++ b/src/librustc/middle/ty.rs
@@ -43,6 +43,7 @@ use syntax::ast_util;
 use syntax::attr;
 use syntax::codemap::span;
 use syntax::codemap;
+use syntax::parse::token;
 use syntax::parse::token::special_idents;
 use syntax::{ast, ast_map};
 use syntax::opt_vec::OptVec;
@@ -2678,7 +2679,7 @@ impl cmp::TotalOrd for bound_region {
             (&ty::br_anon(ref a1), &ty::br_anon(ref a2)) => a1.cmp(a2),
             (&ty::br_anon(*), _) => cmp::Less,
 
-            (&ty::br_named(ref a1), &ty::br_named(ref a2)) => a1.repr.cmp(&a2.repr),
+            (&ty::br_named(ref a1), &ty::br_named(ref a2)) => a1.name.cmp(&a2.name),
             (&ty::br_named(*), _) => cmp::Less,
 
             (&ty::br_cap_avoid(ref a1, @ref b1),
@@ -2819,7 +2820,7 @@ pub fn node_id_to_trait_ref(cx: ctxt, id: ast::node_id) -> @ty::TraitRef {
        None => cx.sess.bug(
            fmt!("node_id_to_trait_ref: no trait ref for node `%s`",
                 ast_map::node_id_to_str(cx.items, id,
-                                        cx.sess.parse_sess.interner)))
+                                        token::get_ident_interner())))
     }
 }
 
@@ -2830,7 +2831,7 @@ pub fn node_id_to_type(cx: ctxt, id: ast::node_id) -> t {
        None => cx.sess.bug(
            fmt!("node_id_to_type: no type for node `%s`",
                 ast_map::node_id_to_str(cx.items, id,
-                                        cx.sess.parse_sess.interner)))
+                                        token::get_ident_interner())))
     }
 }
 
@@ -3821,7 +3822,7 @@ pub fn substd_enum_variants(cx: ctxt,
 }
 
 pub fn item_path_str(cx: ctxt, id: ast::def_id) -> ~str {
-    ast_map::path_to_str(item_path(cx, id), cx.sess.parse_sess.interner)
+    ast_map::path_to_str(item_path(cx, id), token::get_ident_interner())
 }
 
 pub enum DtorKind {
@@ -4107,7 +4108,7 @@ pub fn lookup_struct_fields(cx: ctxt, did: ast::def_id) -> ~[field_ty] {
            cx.sess.bug(
                fmt!("struct ID not bound to an item: %s",
                     ast_map::node_id_to_str(cx.items, did.node,
-                                            cx.sess.parse_sess.interner)));
+                                            token::get_ident_interner())));
        }
     }
         }
diff --git a/src/librustc/middle/typeck/check/mod.rs b/src/librustc/middle/typeck/check/mod.rs
index dc8a47ca209..c69aeeb4aa8 100644
--- a/src/librustc/middle/typeck/check/mod.rs
+++ b/src/librustc/middle/typeck/check/mod.rs
@@ -127,6 +127,7 @@ use syntax::codemap::span;
 use syntax::codemap;
 use syntax::opt_vec::OptVec;
 use syntax::opt_vec;
+use syntax::parse::token;
 use syntax::parse::token::special_idents;
 use syntax::print::pprust;
 use syntax::visit;
@@ -815,7 +816,7 @@ impl FnCtxt {
                     fmt!("no type for node %d: %s in fcx %s",
                          id, ast_map::node_id_to_str(
                              self.tcx().items, id,
-                             self.tcx().sess.parse_sess.interner),
+                             token::get_ident_interner()),
                          self.tag()));
             }
         }
@@ -829,7 +830,7 @@ impl FnCtxt {
                     fmt!("no type substs for node %d: %s in fcx %s",
                          id, ast_map::node_id_to_str(
                              self.tcx().items, id,
-                             self.tcx().sess.parse_sess.interner),
+                             token::get_ident_interner()),
                          self.tag()));
             }
         }
diff --git a/src/librustc/util/ppaux.rs b/src/librustc/util/ppaux.rs
index 4ffa4d0d25e..2ec4cc65528 100644
--- a/src/librustc/util/ppaux.rs
+++ b/src/librustc/util/ppaux.rs
@@ -28,6 +28,7 @@ use middle::typeck;
 use syntax::abi::AbiSet;
 use syntax::ast_map;
 use syntax::codemap::span;
+use syntax::parse::token;
 use syntax::print::pprust;
 use syntax::{ast, ast_util};
 
@@ -200,7 +201,7 @@ pub fn re_scope_id_to_str(cx: ctxt, node_id: ast::node_id) -> ~str {
       _ => { cx.sess.bug(
           fmt!("re_scope refers to %s",
                ast_map::node_id_to_str(cx.items, node_id,
-                                       cx.sess.parse_sess.interner))) }
+                                       token::get_ident_interner()))) }
     }
 }
 
@@ -654,7 +655,7 @@ impl Repr for ty::Method {
 
 impl Repr for ast::ident {
     fn repr(&self, tcx: ctxt) -> ~str {
-        copy *tcx.sess.intr().get(*self)
+        copy *token::ident_to_str(self)
     }
 }
 
diff --git a/src/librustdoc/extract.rs b/src/librustdoc/extract.rs
index 920a72077f0..1175175c2d6 100644
--- a/src/librustdoc/extract.rs
+++ b/src/librustdoc/extract.rs
@@ -18,16 +18,17 @@ use doc;
 
 use core::vec;
 use syntax::ast;
-use syntax::parse::token::{ident_interner};
+use syntax::parse::token::{ident_interner, ident_to_str};
 use syntax::parse::token;
 
 // Hack; rather than thread an interner through everywhere, rely on
 // thread-local data
+// Hack-Becomes-Feature: using thread-local-state everywhere...
 pub fn to_str(id: ast::ident) -> ~str {
-    let intr = token::get_ident_interner();
-    return copy *(*intr).get(id);
+    return copy *ident_to_str(&id);
 }
 
+// get rid of this pointless function:
 pub fn interner() -> @ident_interner {
     return token::get_ident_interner();
 }
diff --git a/src/librustdoc/tystr_pass.rs b/src/librustdoc/tystr_pass.rs
index 57a45d3dcc2..82336addb62 100644
--- a/src/librustdoc/tystr_pass.rs
+++ b/src/librustdoc/tystr_pass.rs
@@ -24,6 +24,7 @@ use pass::Pass;
 use core::vec;
 use syntax::ast;
 use syntax::print::pprust;
+use syntax::parse::token;
 use syntax::ast_map;
 
 pub fn mk_pass() -> Pass {
@@ -76,7 +77,7 @@ fn get_fn_sig(srv: astsrv::Srv, fn_id: doc::AstId) -> Option<~str> {
                 node: ast::foreign_item_fn(ref decl, purity, ref tys), _
             }, _, _, _) => {
                 Some(pprust::fun_to_str(decl, purity, ident, None, tys,
-                                        extract::interner()))
+                                       token::get_ident_interner()))
             }
             _ => fail!("get_fn_sig: fn_id not bound to a fn item")
         }
diff --git a/src/librusti/rusti.rc b/src/librusti/rusti.rc
index 56a87eb8055..88482c94336 100644
--- a/src/librusti/rusti.rc
+++ b/src/librusti/rusti.rc
@@ -174,7 +174,7 @@ fn run(repl: Repl, input: ~str) -> Repl {
         _ => fail!()
     };
     debug!("recording input into repl history");
-    record(repl, blk, sess.parse_sess.interner)
+    record(repl, blk, token::get_ident_interner())
 }
 
 // Compiles a crate given by the filename as a library if the compiled
diff --git a/src/libstd/rand.rs b/src/libstd/rand.rs
index a6c1dca4342..b763c1c2d76 100644
--- a/src/libstd/rand.rs
+++ b/src/libstd/rand.rs
@@ -25,7 +25,7 @@ distributions like normal and exponential.
 use core::rand::RngUtil;
 
 fn main() {
-    let rng = rand::rng();
+    let mut rng = rand::rng();
     if rng.gen() { // bool
         println(fmt!("int: %d, uint: %u", rng.gen(), rng.gen()))
     }
diff --git a/src/libsyntax/ast.rs b/src/libsyntax/ast.rs
index 625bcd4ec9c..5bbc5d4e819 100644
--- a/src/libsyntax/ast.rs
+++ b/src/libsyntax/ast.rs
@@ -15,7 +15,7 @@ use core::prelude::*;
 use codemap::{span, spanned};
 use abi::AbiSet;
 use opt_vec::OptVec;
-use parse::token::get_ident_interner;
+use parse::token::{ident_to_str, interner_get, str_to_ident};
 
 use core::hashmap::HashMap;
 use core::option::Option;
@@ -25,12 +25,15 @@ use core::to_str::ToStr;
 use extra::serialize::{Encodable, Decodable, Encoder, Decoder};
 
 
-// an identifier contains an index into the interner
-// table and a SyntaxContext to track renaming and
+// an identifier contains a Name (index into the interner
+// table) and a SyntaxContext to track renaming and
 // macro expansion per Flatt et al., "Macros
 // That Work Together"
 #[deriving(Eq)]
-pub struct ident { repr: Name, ctxt: SyntaxContext }
+pub struct ident { name: Name, ctxt: SyntaxContext }
+
+/// Construct an identifier with the given name and an empty context:
+pub fn new_ident(name: Name) -> ident { ident {name: name, ctxt: empty_ctxt}}
 
 // a SyntaxContext represents a chain of macro-expandings
 // and renamings. Each macro expansion corresponds to
@@ -72,7 +75,8 @@ pub enum SyntaxContext_ {
     IllegalCtxt()
 }
 
-// a name represents an identifier
+// a name is a part of an identifier, representing a string
+// or gensym. It's the result of interning.
 pub type Name = uint;
 // a mark represents a unique id associated
 // with a macro expansion
@@ -80,22 +84,20 @@ pub type Mrk = uint;
 
 impl<S:Encoder> Encodable<S> for ident {
     fn encode(&self, s: &mut S) {
-        let intr = get_ident_interner();
-        s.emit_str(*(*intr).get(*self));
+        s.emit_str(*interner_get(self.name));
     }
 }
 
 impl<D:Decoder> Decodable<D> for ident {
     fn decode(d: &mut D) -> ident {
-        let intr = get_ident_interner();
-        (*intr).intern(d.read_str())
+        str_to_ident(d.read_str())
     }
 }
 
 impl to_bytes::IterBytes for ident {
     #[inline(always)]
     fn iter_bytes(&self, lsb0: bool, f: to_bytes::Cb) -> bool {
-        self.repr.iter_bytes(lsb0, f)
+        self.name.iter_bytes(lsb0, f)
     }
 }
 
@@ -385,6 +387,7 @@ pub type stmt = spanned<stmt_>;
 
 #[deriving(Eq, Encodable, Decodable)]
 pub enum stmt_ {
+    // could be an item or a local (let) binding:
     stmt_decl(@decl, node_id),
 
     // expr without trailing semi-colon (must have unit type):
@@ -414,7 +417,9 @@ pub type decl = spanned<decl_>;
 
 #[deriving(Eq, Encodable, Decodable)]
 pub enum decl_ {
+    // a local (let) binding:
     decl_local(@local),
+    // an item binding:
     decl_item(@item),
 }
 
diff --git a/src/libsyntax/ast_map.rs b/src/libsyntax/ast_map.rs
index 53150bb1010..ec77ba88530 100644
--- a/src/libsyntax/ast_map.rs
+++ b/src/libsyntax/ast_map.rs
@@ -58,8 +58,8 @@ pub fn path_to_str_with_sep(p: &[path_elt], sep: &str, itr: @ident_interner)
                          -> ~str {
     let strs = do p.map |e| {
         match *e {
-          path_mod(s) => copy *itr.get(s),
-          path_name(s) => copy *itr.get(s)
+          path_mod(s) => copy *itr.get(s.name),
+          path_name(s) => copy *itr.get(s.name)
         }
     };
     str::connect(strs, sep)
@@ -68,9 +68,9 @@ pub fn path_to_str_with_sep(p: &[path_elt], sep: &str, itr: @ident_interner)
 pub fn path_ident_to_str(p: &path, i: ident, itr: @ident_interner) -> ~str {
     if vec::is_empty(*p) {
         //FIXME /* FIXME (#2543) */ copy *i
-        copy *itr.get(i)
+        copy *itr.get(i.name)
     } else {
-        fmt!("%s::%s", path_to_str(*p, itr), *itr.get(i))
+        fmt!("%s::%s", path_to_str(*p, itr), *itr.get(i.name))
     }
 }
 
@@ -80,8 +80,8 @@ pub fn path_to_str(p: &[path_elt], itr: @ident_interner) -> ~str {
 
 pub fn path_elt_to_str(pe: path_elt, itr: @ident_interner) -> ~str {
     match pe {
-        path_mod(s) => copy *itr.get(s),
-        path_name(s) => copy *itr.get(s)
+        path_mod(s) => copy *itr.get(s.name),
+        path_name(s) => copy *itr.get(s.name)
     }
 }
 
@@ -356,16 +356,16 @@ pub fn node_id_to_str(map: map, id: node_id, itr: @ident_interner) -> ~str {
       }
       Some(&node_method(m, _, path)) => {
         fmt!("method %s in %s (id=%?)",
-             *itr.get(m.ident), path_to_str(*path, itr), id)
+             *itr.get(m.ident.name), path_to_str(*path, itr), id)
       }
       Some(&node_trait_method(ref tm, _, path)) => {
         let m = ast_util::trait_method_to_ty_method(&**tm);
         fmt!("method %s in %s (id=%?)",
-             *itr.get(m.ident), path_to_str(*path, itr), id)
+             *itr.get(m.ident.name), path_to_str(*path, itr), id)
       }
       Some(&node_variant(ref variant, _, path)) => {
         fmt!("variant %s in %s (id=%?)",
-             *itr.get(variant.node.name), path_to_str(*path, itr), id)
+             *itr.get(variant.node.name.name), path_to_str(*path, itr), id)
       }
       Some(&node_expr(expr)) => {
         fmt!("expr %s (id=%?)", pprust::expr_to_str(expr, itr), id)
@@ -381,7 +381,7 @@ pub fn node_id_to_str(map: map, id: node_id, itr: @ident_interner) -> ~str {
         fmt!("arg (id=%?)", id)
       }
       Some(&node_local(ident)) => {
-        fmt!("local (id=%?, name=%s)", id, *itr.get(ident))
+        fmt!("local (id=%?, name=%s)", id, *itr.get(ident.name))
       }
       Some(&node_block(_)) => {
         fmt!("block")
diff --git a/src/libsyntax/ast_util.rs b/src/libsyntax/ast_util.rs
index e2b8677d5a4..d99363d7ee5 100644
--- a/src/libsyntax/ast_util.rs
+++ b/src/libsyntax/ast_util.rs
@@ -14,6 +14,8 @@ use ast::*;
 use ast;
 use ast_util;
 use codemap::{span, spanned};
+use core::cast;
+use core::local_data;
 use opt_vec;
 use parse::token;
 use visit;
@@ -24,12 +26,11 @@ use core::option;
 use core::str;
 use core::to_bytes;
 
-pub fn path_name_i(idents: &[ident], intr: @token::ident_interner) -> ~str {
+pub fn path_name_i(idents: &[ident]) -> ~str {
     // FIXME: Bad copies (#2543 -- same for everything else that says "bad")
-    str::connect(idents.map(|i| copy *intr.get(*i)), "::")
+    str::connect(idents.map(|i| copy *token::interner_get(i.name)), "::")
 }
 
-
 pub fn path_to_ident(p: @Path) -> ident { copy *p.idents.last() }
 
 pub fn local_def(id: node_id) -> def_id {
@@ -620,16 +621,22 @@ pub enum Privacy {
 
 // HYGIENE FUNCTIONS
 
-/// Construct an identifier with the given repr and an empty context:
-pub fn new_ident(repr: uint) -> ident { ident {repr: repr, ctxt: 0}}
+/// Construct an identifier with the given name and an empty context:
+pub fn new_ident(name: Name) -> ident { ident {name: name, ctxt: 0}}
 
 /// Extend a syntax context with a given mark
-pub fn new_mark (m:Mrk, tail:SyntaxContext,table:&mut SCTable)
+pub fn new_mark(m:Mrk, tail:SyntaxContext) -> SyntaxContext {
+    new_mark_internal(m,tail,get_sctable())
+}
+
+// Extend a syntax context with a given mark and table
+// FIXME #4536 : currently pub to allow testing
+pub fn new_mark_internal(m:Mrk, tail:SyntaxContext,table:&mut SCTable)
     -> SyntaxContext {
     let key = (tail,m);
     // FIXME #5074 : can't use more natural style because we're missing
     // flow-sensitivity. Results in two lookups on a hash table hit.
-    // also applies to new_rename, below.
+    // also applies to new_rename_internal, below.
     // let try_lookup = table.mark_memo.find(&key);
     match table.mark_memo.contains_key(&key) {
         false => {
@@ -647,7 +654,13 @@ pub fn new_mark (m:Mrk, tail:SyntaxContext,table:&mut SCTable)
 }
 
 /// Extend a syntax context with a given rename
-pub fn new_rename (id:ident, to:Name, tail:SyntaxContext, table: &mut SCTable)
+pub fn new_rename(id:ident, to:Name, tail:SyntaxContext) -> SyntaxContext {
+    new_rename_internal(id, to, tail, get_sctable())
+}
+
+// Extend a syntax context with a given rename and sctable
+// FIXME #4536 : currently pub to allow testing
+pub fn new_rename_internal(id:ident, to:Name, tail:SyntaxContext, table: &mut SCTable)
     -> SyntaxContext {
     let key = (tail,id,to);
     // FIXME #5074
@@ -669,7 +682,8 @@ pub fn new_rename (id:ident, to:Name, tail:SyntaxContext, table: &mut SCTable)
 
 /// Make a fresh syntax context table with EmptyCtxt in slot zero
 /// and IllegalCtxt in slot one.
-pub fn new_sctable() -> SCTable {
+// FIXME #4536 : currently pub to allow testing
+pub fn new_sctable_internal() -> SCTable {
     SCTable {
         table: ~[EmptyCtxt,IllegalCtxt],
         mark_memo: HashMap::new(),
@@ -677,6 +691,23 @@ pub fn new_sctable() -> SCTable {
     }
 }
 
+// fetch the SCTable from TLS, create one if it doesn't yet exist.
+pub fn get_sctable() -> @mut SCTable {
+    unsafe {
+        let sctable_key = (cast::transmute::<(uint, uint),
+                           &fn(v: @@mut SCTable)>(
+                               (-4 as uint, 0u)));
+        match local_data::local_data_get(sctable_key) {
+            None => {
+                let new_table = @@mut new_sctable_internal();
+                local_data::local_data_set(sctable_key,new_table);
+                *new_table
+            },
+            Some(intr) => *intr
+        }
+    }
+}
+
 /// Add a value to the end of a vec, return its index
 fn idx_push<T>(vec: &mut ~[T], val: T) -> uint {
     vec.push(val);
@@ -684,19 +715,25 @@ fn idx_push<T>(vec: &mut ~[T], val: T) -> uint {
 }
 
 /// Resolve a syntax object to a name, per MTWT.
-pub fn resolve (id : ident, table : &mut SCTable) -> Name {
+pub fn resolve(id : ident) -> Name {
+    resolve_internal(id, get_sctable())
+}
+
+// Resolve a syntax object to a name, per MTWT.
+// FIXME #4536 : currently pub to allow testing
+pub fn resolve_internal(id : ident, table : &mut SCTable) -> Name {
     match table.table[id.ctxt] {
-        EmptyCtxt => id.repr,
+        EmptyCtxt => id.name,
         // ignore marks here:
-        Mark(_,subctxt) => resolve (ident{repr:id.repr, ctxt: subctxt},table),
+        Mark(_,subctxt) => resolve_internal(ident{name:id.name, ctxt: subctxt},table),
         // do the rename if necessary:
-        Rename(ident{repr,ctxt},toname,subctxt) => {
+        Rename(ident{name,ctxt},toname,subctxt) => {
             // this could be cached or computed eagerly:
-            let resolvedfrom = resolve(ident{repr:repr,ctxt:ctxt},table);
-            let resolvedthis = resolve(ident{repr:id.repr,ctxt:subctxt},table);
+            let resolvedfrom = resolve_internal(ident{name:name,ctxt:ctxt},table);
+            let resolvedthis = resolve_internal(ident{name:id.name,ctxt:subctxt},table);
             if ((resolvedthis == resolvedfrom)
-                && (marksof (ctxt,resolvedthis,table)
-                    == marksof (subctxt,resolvedthis,table))) {
+                && (marksof(ctxt,resolvedthis,table)
+                    == marksof(subctxt,resolvedthis,table))) {
                 toname
             } else {
                 resolvedthis
@@ -777,11 +814,11 @@ mod test {
     // convert a list of uints to an @~[ident]
     // (ignores the interner completely)
     fn uints_to_idents (uints: &~[uint]) -> @~[ident] {
-        @uints.map(|u|{ ident {repr:*u, ctxt: empty_ctxt} })
+        @uints.map(|u|{ ident {name:*u, ctxt: empty_ctxt} })
     }
 
     fn id (u : uint, s: SyntaxContext) -> ident {
-        ident{repr:u, ctxt: s}
+        ident{name:u, ctxt: s}
     }
 
     // because of the SCTable, I now need a tidy way of
@@ -798,8 +835,8 @@ mod test {
         -> SyntaxContext {
         tscs.foldr(tail, |tsc : &TestSC,tail : SyntaxContext|
                   {match *tsc {
-                      M(mrk) => new_mark(mrk,tail,table),
-                      R(ident,name) => new_rename(ident,name,tail,table)}})
+                      M(mrk) => new_mark_internal(mrk,tail,table),
+                      R(ident,name) => new_rename_internal(ident,name,tail,table)}})
     }
 
     // gather a SyntaxContext back into a vector of TestSCs
@@ -824,7 +861,7 @@ mod test {
     }
 
     #[test] fn test_unfold_refold(){
-        let mut t = new_sctable();
+        let mut t = new_sctable_internal();
 
         let test_sc = ~[M(3),R(id(101,0),14),M(9)];
         assert_eq!(unfold_test_sc(copy test_sc,empty_ctxt,&mut t),4);
@@ -838,11 +875,11 @@ mod test {
     // in a vector. v[0] will be the outermost mark.
     fn unfold_marks(mrks:~[Mrk],tail:SyntaxContext,table: &mut SCTable) -> SyntaxContext {
         mrks.foldr(tail, |mrk:&Mrk,tail:SyntaxContext|
-                   {new_mark(*mrk,tail,table)})
+                   {new_mark_internal(*mrk,tail,table)})
     }
 
     #[test] fn unfold_marks_test() {
-        let mut t = new_sctable();
+        let mut t = new_sctable_internal();
 
         assert_eq!(unfold_marks(~[3,7],empty_ctxt,&mut t),3);
         assert_eq!(t.table[2],Mark(7,0));
@@ -852,7 +889,7 @@ mod test {
     #[test] fn test_marksof () {
         let stopname = 242;
         let name1 = 243;
-        let mut t = new_sctable();
+        let mut t = new_sctable_internal();
         assert_eq!(marksof (empty_ctxt,stopname,&t),~[]);
         // FIXME #5074: ANF'd to dodge nested calls
         { let ans = unfold_marks(~[4,98],empty_ctxt,&mut t);
@@ -866,13 +903,13 @@ mod test {
         // rename where stop doesn't match:
         { let chain = ~[M(9),
                         R(id(name1,
-                             new_mark (4, empty_ctxt,&mut t)),
+                             new_mark_internal (4, empty_ctxt,&mut t)),
                           100101102),
                         M(14)];
          let ans = unfold_test_sc(chain,empty_ctxt,&mut t);
          assert_eq! (marksof (ans, stopname, &t), ~[9,14]);}
         // rename where stop does match
-        { let name1sc = new_mark(4, empty_ctxt, &mut t);
+        { let name1sc = new_mark_internal(4, empty_ctxt, &mut t);
          let chain = ~[M(9),
                        R(id(name1, name1sc),
                          stopname),
@@ -884,30 +921,30 @@ mod test {
 
     #[test] fn resolve_tests () {
         let a = 40;
-        let mut t = new_sctable();
+        let mut t = new_sctable_internal();
         // - ctxt is MT
-        assert_eq!(resolve(id(a,empty_ctxt),&mut t),a);
+        assert_eq!(resolve_internal(id(a,empty_ctxt),&mut t),a);
         // - simple ignored marks
         { let sc = unfold_marks(~[1,2,3],empty_ctxt,&mut t);
-         assert_eq!(resolve(id(a,sc),&mut t),a);}
+         assert_eq!(resolve_internal(id(a,sc),&mut t),a);}
         // - orthogonal rename where names don't match
         { let sc = unfold_test_sc(~[R(id(50,empty_ctxt),51),M(12)],empty_ctxt,&mut t);
-         assert_eq!(resolve(id(a,sc),&mut t),a);}
+         assert_eq!(resolve_internal(id(a,sc),&mut t),a);}
         // - rename where names do match, but marks don't
-        { let sc1 = new_mark(1,empty_ctxt,&mut t);
+        { let sc1 = new_mark_internal(1,empty_ctxt,&mut t);
          let sc = unfold_test_sc(~[R(id(a,sc1),50),
                                    M(1),
                                    M(2)],
                                  empty_ctxt,&mut t);
-        assert_eq!(resolve(id(a,sc),&mut t), a);}
+        assert_eq!(resolve_internal(id(a,sc),&mut t), a);}
         // - rename where names and marks match
         { let sc1 = unfold_test_sc(~[M(1),M(2)],empty_ctxt,&mut t);
          let sc = unfold_test_sc(~[R(id(a,sc1),50),M(1),M(2)],empty_ctxt,&mut t);
-         assert_eq!(resolve(id(a,sc),&mut t), 50); }
+         assert_eq!(resolve_internal(id(a,sc),&mut t), 50); }
         // - rename where names and marks match by literal sharing
         { let sc1 = unfold_test_sc(~[M(1),M(2)],empty_ctxt,&mut t);
          let sc = unfold_test_sc(~[R(id(a,sc1),50)],sc1,&mut t);
-         assert_eq!(resolve(id(a,sc),&mut t), 50); }
+         assert_eq!(resolve_internal(id(a,sc),&mut t), 50); }
         // - two renames of the same var.. can only happen if you use
         // local-expand to prevent the inner binding from being renamed
         // during the rename-pass caused by the first:
@@ -915,28 +952,28 @@ mod test {
         { let sc = unfold_test_sc(~[R(id(a,empty_ctxt),50),
                                     R(id(a,empty_ctxt),51)],
                                   empty_ctxt,&mut t);
-         assert_eq!(resolve(id(a,sc),&mut t), 51); }
+         assert_eq!(resolve_internal(id(a,sc),&mut t), 51); }
         // the simplest double-rename:
-        { let a_to_a50 = new_rename(id(a,empty_ctxt),50,empty_ctxt,&mut t);
-         let a50_to_a51 = new_rename(id(a,a_to_a50),51,a_to_a50,&mut t);
-         assert_eq!(resolve(id(a,a50_to_a51),&mut t),51);
+        { let a_to_a50 = new_rename_internal(id(a,empty_ctxt),50,empty_ctxt,&mut t);
+         let a50_to_a51 = new_rename_internal(id(a,a_to_a50),51,a_to_a50,&mut t);
+         assert_eq!(resolve_internal(id(a,a50_to_a51),&mut t),51);
          // mark on the outside doesn't stop rename:
-         let sc = new_mark(9,a50_to_a51,&mut t);
-         assert_eq!(resolve(id(a,sc),&mut t),51);
+         let sc = new_mark_internal(9,a50_to_a51,&mut t);
+         assert_eq!(resolve_internal(id(a,sc),&mut t),51);
          // but mark on the inside does:
          let a50_to_a51_b = unfold_test_sc(~[R(id(a,a_to_a50),51),
                                               M(9)],
                                            a_to_a50,
                                            &mut t);
-         assert_eq!(resolve(id(a,a50_to_a51_b),&mut t),50);}
+         assert_eq!(resolve_internal(id(a,a50_to_a51_b),&mut t),50);}
     }
 
     #[test] fn hashing_tests () {
-        let mut t = new_sctable();
-        assert_eq!(new_mark(12,empty_ctxt,&mut t),2);
-        assert_eq!(new_mark(13,empty_ctxt,&mut t),3);
+        let mut t = new_sctable_internal();
+        assert_eq!(new_mark_internal(12,empty_ctxt,&mut t),2);
+        assert_eq!(new_mark_internal(13,empty_ctxt,&mut t),3);
         // using the same one again should result in the same index:
-        assert_eq!(new_mark(12,empty_ctxt,&mut t),2);
+        assert_eq!(new_mark_internal(12,empty_ctxt,&mut t),2);
         // I'm assuming that the rename table will behave the same....
     }
 
diff --git a/src/libsyntax/ext/base.rs b/src/libsyntax/ext/base.rs
index 5fae6ff3c18..a3432a00edc 100644
--- a/src/libsyntax/ext/base.rs
+++ b/src/libsyntax/ext/base.rs
@@ -11,6 +11,7 @@
 use core::prelude::*;
 
 use ast;
+use ast::Name;
 use codemap;
 use codemap::{CodeMap, span, ExpnInfo, ExpandedFrom};
 use codemap::CallInfo;
@@ -18,6 +19,7 @@ use diagnostic::span_handler;
 use ext;
 use parse;
 use parse::token;
+use parse::token::{ident_to_str, intern, str_to_ident};
 
 use core::hashmap::HashMap;
 use core::vec;
@@ -91,29 +93,33 @@ pub enum SyntaxExtension {
     IdentTT(SyntaxExpanderTTItem),
 }
 
+// The SyntaxEnv is the environment that's threaded through the expansion
+// of macros. It contains bindings for macros, and also a special binding
+// for " block" (not a legal identifier) that maps to a BlockInfo
 pub type SyntaxEnv = @mut MapChain<Name, Transformer>;
 
-// Name : the domain of SyntaxEnvs
-// want to change these to uints....
-// note that we use certain strings that are not legal as identifiers
-// to indicate, for instance, how blocks are supposed to behave.
-type Name = @~str;
-
 // Transformer : the codomain of SyntaxEnvs
 
-// NB: it may seem crazy to lump both of these into one environment;
-// what would it mean to bind "foo" to BlockLimit(true)? The idea
-// is that this follows the lead of MTWT, and accommodates growth
-// toward a more uniform syntax syntax (sorry) where blocks are just
-// another kind of transformer.
-
 pub enum Transformer {
     // this identifier maps to a syntax extension or macro
     SE(SyntaxExtension),
-    // should blocks occurring here limit macro scopes?
-    ScopeMacros(bool)
+    // blockinfo : this is ... well, it's simpler than threading
+    // another whole data stack-structured data structure through
+    // expansion. Basically, there's an invariant that every
+    // map must contain a binding for " block".
+    BlockInfo(BlockInfo)
 }
 
+pub struct BlockInfo {
+    // should macros escape from this scope?
+    macros_escape : bool,
+    // what are the pending renames?
+    pending_renames : @mut RenameList
+}
+
+// a list of ident->name renamings
+type RenameList = ~[(ast::ident,Name)];
+
 // The base map of methods for expanding syntax extension
 // AST nodes into full ASTs
 pub fn syntax_expander_table() -> SyntaxEnv {
@@ -127,77 +133,80 @@ pub fn syntax_expander_table() -> SyntaxEnv {
     }
     let mut syntax_expanders = HashMap::new();
     // NB identifier starts with space, and can't conflict with legal idents
-    syntax_expanders.insert(@~" block",
-                            @ScopeMacros(true));
-    syntax_expanders.insert(@~"macro_rules",
+    syntax_expanders.insert(intern(&" block"),
+                            @BlockInfo(BlockInfo{
+                                macros_escape : false,
+                                pending_renames : @mut ~[]
+                            }));
+    syntax_expanders.insert(intern(&"macro_rules"),
                             builtin_item_tt(
                                 ext::tt::macro_rules::add_new_extension));
-    syntax_expanders.insert(@~"fmt",
+    syntax_expanders.insert(intern(&"fmt"),
                             builtin_normal_tt(ext::fmt::expand_syntax_ext));
     syntax_expanders.insert(
-        @~"auto_encode",
+        intern(&"auto_encode"),
         @SE(ItemDecorator(ext::auto_encode::expand_auto_encode)));
     syntax_expanders.insert(
-        @~"auto_decode",
+        intern(&"auto_decode"),
         @SE(ItemDecorator(ext::auto_encode::expand_auto_decode)));
-    syntax_expanders.insert(@~"env",
+    syntax_expanders.insert(intern(&"env"),
                             builtin_normal_tt(ext::env::expand_syntax_ext));
-    syntax_expanders.insert(@~"bytes",
+    syntax_expanders.insert(intern("bytes"),
                             builtin_normal_tt(ext::bytes::expand_syntax_ext));
-    syntax_expanders.insert(@~"concat_idents",
+    syntax_expanders.insert(intern("concat_idents"),
                             builtin_normal_tt(
                                 ext::concat_idents::expand_syntax_ext));
-    syntax_expanders.insert(@~"log_syntax",
+    syntax_expanders.insert(intern(&"log_syntax"),
                             builtin_normal_tt(
                                 ext::log_syntax::expand_syntax_ext));
-    syntax_expanders.insert(@~"deriving",
+    syntax_expanders.insert(intern(&"deriving"),
                             @SE(ItemDecorator(
                                 ext::deriving::expand_meta_deriving)));
 
     // Quasi-quoting expanders
-    syntax_expanders.insert(@~"quote_tokens",
+    syntax_expanders.insert(intern(&"quote_tokens"),
                        builtin_normal_tt(ext::quote::expand_quote_tokens));
-    syntax_expanders.insert(@~"quote_expr",
+    syntax_expanders.insert(intern(&"quote_expr"),
                        builtin_normal_tt(ext::quote::expand_quote_expr));
-    syntax_expanders.insert(@~"quote_ty",
+    syntax_expanders.insert(intern(&"quote_ty"),
                        builtin_normal_tt(ext::quote::expand_quote_ty));
-    syntax_expanders.insert(@~"quote_item",
+    syntax_expanders.insert(intern(&"quote_item"),
                        builtin_normal_tt(ext::quote::expand_quote_item));
-    syntax_expanders.insert(@~"quote_pat",
+    syntax_expanders.insert(intern(&"quote_pat"),
                        builtin_normal_tt(ext::quote::expand_quote_pat));
-    syntax_expanders.insert(@~"quote_stmt",
+    syntax_expanders.insert(intern(&"quote_stmt"),
                        builtin_normal_tt(ext::quote::expand_quote_stmt));
 
-    syntax_expanders.insert(@~"line",
+    syntax_expanders.insert(intern(&"line"),
                             builtin_normal_tt(
                                 ext::source_util::expand_line));
-    syntax_expanders.insert(@~"col",
+    syntax_expanders.insert(intern(&"col"),
                             builtin_normal_tt(
                                 ext::source_util::expand_col));
-    syntax_expanders.insert(@~"file",
+    syntax_expanders.insert(intern(&"file"),
                             builtin_normal_tt(
                                 ext::source_util::expand_file));
-    syntax_expanders.insert(@~"stringify",
+    syntax_expanders.insert(intern(&"stringify"),
                             builtin_normal_tt(
                                 ext::source_util::expand_stringify));
-    syntax_expanders.insert(@~"include",
+    syntax_expanders.insert(intern(&"include"),
                             builtin_normal_tt(
                                 ext::source_util::expand_include));
-    syntax_expanders.insert(@~"include_str",
+    syntax_expanders.insert(intern(&"include_str"),
                             builtin_normal_tt(
                                 ext::source_util::expand_include_str));
-    syntax_expanders.insert(@~"include_bin",
+    syntax_expanders.insert(intern(&"include_bin"),
                             builtin_normal_tt(
                                 ext::source_util::expand_include_bin));
-    syntax_expanders.insert(@~"module_path",
+    syntax_expanders.insert(intern(&"module_path"),
                             builtin_normal_tt(
                                 ext::source_util::expand_mod));
-    syntax_expanders.insert(@~"proto",
+    syntax_expanders.insert(intern(&"proto"),
                             builtin_item_tt(ext::pipes::expand_proto));
-    syntax_expanders.insert(@~"asm",
+    syntax_expanders.insert(intern(&"asm"),
                             builtin_normal_tt(ext::asm::expand_asm));
     syntax_expanders.insert(
-        @~"trace_macros",
+        intern(&"trace_macros"),
         builtin_normal_tt(ext::trace_macros::expand_trace_macros));
     MapChain::new(~syntax_expanders)
 }
@@ -301,10 +310,10 @@ impl ExtCtxt {
         *self.trace_mac = x
     }
     pub fn str_of(&self, id: ast::ident) -> ~str {
-        copy *self.parse_sess.interner.get(id)
+        copy *ident_to_str(&id)
     }
     pub fn ident_of(&self, st: &str) -> ast::ident {
-        self.parse_sess.interner.intern(st)
+        str_to_ident(st)
     }
 }
 
@@ -470,6 +479,15 @@ impl <K: Eq + Hash + IterBytes ,V: Copy> MapChain<K,V>{
         }
     }
 
+    fn find_in_topmost_frame(&self, key: &K) -> Option<@V> {
+        let map = match *self {
+            BaseMapChain(ref map) => map,
+            ConsMapChain(ref map,_) => map
+        };
+        // strip one layer of indirection off the pointer.
+        map.find(key).map(|r| {**r})
+    }
+
     // insert the binding into the top-level map
     fn insert (&mut self, key: K, ext: @V) -> bool {
         // can't abstract over get_map because of flow sensitivity...
@@ -478,7 +496,40 @@ impl <K: Eq + Hash + IterBytes ,V: Copy> MapChain<K,V>{
             ConsMapChain (~ref mut map,_) => map.insert(key,ext)
         }
     }
+    // insert the binding into the topmost frame for which the binding
+    // associated with 'n' exists and satisfies pred
+    // ... there are definitely some opportunities for abstraction
+    // here that I'm ignoring. (e.g., manufacturing a predicate on
+    // the maps in the chain, and using an abstract "find".
+    fn insert_into_frame(&mut self, key: K, ext: @V, n: K, pred: &fn(&@V)->bool) {
+        match *self {
+            BaseMapChain (~ref mut map) => {
+                if satisfies_pred(map,&n,pred) {
+                    map.insert(key,ext);
+                } else {
+                    fail!(~"expected map chain containing satisfying frame")
+                }
+            },
+            ConsMapChain (~ref mut map, rest) => {
+                if satisfies_pred(map,&n,pred) {
+                    map.insert(key,ext);
+                } else {
+                    rest.insert_into_frame(key,ext,n,pred)
+                }
+            }
+        }
+    }
+}
 
+// returns true if the binding for 'n' satisfies 'pred' in 'map'
+fn satisfies_pred<K : Eq + Hash + IterBytes,V>(map : &mut HashMap<K,V>,
+                                               n: &K,
+                                               pred: &fn(&V)->bool)
+    -> bool {
+    match map.find(n) {
+        Some(ref v) => (pred(*v)),
+        None => false
+    }
 }
 
 #[cfg(test)]
diff --git a/src/libsyntax/ext/concat_idents.rs b/src/libsyntax/ext/concat_idents.rs
index 358f4041dd0..bfb234106b8 100644
--- a/src/libsyntax/ext/concat_idents.rs
+++ b/src/libsyntax/ext/concat_idents.rs
@@ -15,6 +15,7 @@ use codemap::span;
 use ext::base::*;
 use ext::base;
 use parse::token;
+use parse::token::{str_to_ident};
 
 pub fn expand_syntax_ext(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
     -> base::MacResult {
@@ -33,7 +34,7 @@ pub fn expand_syntax_ext(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
             }
         }
     }
-    let res = cx.parse_sess().interner.intern(res_str);
+    let res = str_to_ident(res_str);
 
     let e = @ast::expr {
         id: cx.next_id(),
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index 45b9be07a98..96a0461de1e 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -11,11 +11,11 @@
 use core::prelude::*;
 
 use ast::{blk_, attribute_, attr_outer, meta_word};
-use ast::{crate, expr_, expr_mac, mac_invoc_tt};
-use ast::{item_mac, stmt_, stmt_mac, stmt_expr, stmt_semi};
+use ast::{crate, decl_local, expr_, expr_mac, mac_invoc_tt};
+use ast::{item_mac, local_, stmt_, stmt_decl, stmt_mac, stmt_expr, stmt_semi};
 use ast::{SCTable, illegal_ctxt};
 use ast;
-use ast_util::{new_rename, new_mark, resolve};
+use ast_util::{new_rename, new_mark, resolve, get_sctable};
 use attr;
 use codemap;
 use codemap::{span, CallInfo, ExpandedFrom, NameAndSpan, spanned};
@@ -23,6 +23,9 @@ use ext::base::*;
 use fold::*;
 use parse;
 use parse::{parse_item_from_source_str};
+use parse::token::{ident_to_str, intern, fresh_name};
+use visit;
+use visit::{Visitor,mk_vt};
 
 use core::vec;
 
@@ -46,15 +49,14 @@ pub fn expand_expr(extsbox: @mut SyntaxEnv,
                             fmt!("expected macro name without module \
                                   separators"));
                     }
-                    /* using idents and token::special_idents would make the
-                    the macro names be hygienic */
-                    let extname = cx.parse_sess().interner.get(pth.idents[0]);
+                    let extname = &pth.idents[0];
+                    let extnamestr = ident_to_str(extname);
                     // leaving explicit deref here to highlight unbox op:
-                    match (*extsbox).find(&extname) {
+                    match (*extsbox).find(&extname.name) {
                         None => {
                             cx.span_fatal(
                                 pth.span,
-                                fmt!("macro undefined: '%s'", *extname))
+                                fmt!("macro undefined: '%s'", *extnamestr))
                         }
                         Some(@SE(NormalTT(SyntaxExpanderTT{
                             expander: exp,
@@ -63,7 +65,7 @@ pub fn expand_expr(extsbox: @mut SyntaxEnv,
                             cx.bt_push(ExpandedFrom(CallInfo {
                                 call_site: s,
                                 callee: NameAndSpan {
-                                    name: copy *extname,
+                                    name: copy *extnamestr,
                                     span: exp_sp,
                                 },
                             }));
@@ -76,7 +78,7 @@ pub fn expand_expr(extsbox: @mut SyntaxEnv,
                                         pth.span,
                                         fmt!(
                                             "non-expr macro in expr pos: %s",
-                                            *extname
+                                            *extnamestr
                                         )
                                     )
                                 }
@@ -92,7 +94,7 @@ pub fn expand_expr(extsbox: @mut SyntaxEnv,
                         _ => {
                             cx.span_fatal(
                                 pth.span,
-                                fmt!("'%s' is not a tt-style macro", *extname)
+                                fmt!("'%s' is not a tt-style macro", *extnamestr)
                             )
                         }
                     }
@@ -129,7 +131,7 @@ pub fn expand_mod_items(extsbox: @mut SyntaxEnv,
         do vec::foldr(item.attrs, ~[*item]) |attr, items| {
             let mname = attr::get_attr_name(attr);
 
-            match (*extsbox).find(&mname) {
+            match (*extsbox).find(&intern(*mname)) {
               Some(@SE(ItemDecorator(dec_fn))) => {
                   cx.bt_push(ExpandedFrom(CallInfo {
                       call_site: attr.span,
@@ -153,16 +155,20 @@ pub fn expand_mod_items(extsbox: @mut SyntaxEnv,
 
 // eval $e with a new exts frame:
 macro_rules! with_exts_frame (
-    ($extsboxexpr:expr,$e:expr) =>
+    ($extsboxexpr:expr,$macros_escape:expr,$e:expr) =>
     ({let extsbox = $extsboxexpr;
       let oldexts = *extsbox;
       *extsbox = oldexts.push_frame();
+      extsbox.insert(intern(special_block_name),
+                     @BlockInfo(BlockInfo{macros_escape:$macros_escape,pending_renames:@mut ~[]}));
       let result = $e;
       *extsbox = oldexts;
       result
      })
 )
 
+static special_block_name : &'static str = " block";
+
 // When we enter a module, record it, for the sake of `module!`
 pub fn expand_item(extsbox: @mut SyntaxEnv,
                    cx: @ExtCtxt,
@@ -180,14 +186,8 @@ pub fn expand_item(extsbox: @mut SyntaxEnv,
           match it.node {
               ast::item_mod(_) | ast::item_foreign_mod(_) => {
                   cx.mod_push(it.ident);
-                  let result =
-                      // don't push a macro scope for macro_escape:
-                      if contains_macro_escape(it.attrs) {
-                      orig(it,fld)
-                  } else {
-                      // otherwise, push a scope:
-                      with_exts_frame!(extsbox,orig(it,fld))
-                  };
+                  let macro_escape = contains_macro_escape(it.attrs);
+                  let result = with_exts_frame!(extsbox,macro_escape,orig(it,fld));
                   cx.mod_pop();
                   result
               }
@@ -203,31 +203,6 @@ pub fn contains_macro_escape (attrs: &[ast::attribute]) -> bool {
     attrs.any(|attr| "macro_escape" == *attr::get_attr_name(attr))
 }
 
-// this macro disables (one layer of) macro
-// scoping, to allow a block to add macro bindings
-// to its parent env
-macro_rules! without_macro_scoping(
-    ($extsexpr:expr,$exp:expr) =>
-    ({
-        // only evaluate this once:
-        let exts = $extsexpr;
-        // capture the existing binding:
-        let existingBlockBinding =
-            match exts.find(&@~" block"){
-                Some(binding) => binding,
-                None => cx.bug("expected to find \" block\" binding")
-            };
-        // this prevents the block from limiting the macros' scope:
-        exts.insert(@~" block",@ScopeMacros(false));
-        let result = $exp;
-        // reset the block binding. Note that since the original
-        // one may have been inherited, this procedure may wind
-        // up introducing a block binding where one didn't exist
-        // before.
-        exts.insert(@~" block",existingBlockBinding);
-        result
-    }))
-
 // Support for item-position macro invocations, exactly the same
 // logic as for expression-position macro invocations.
 pub fn expand_item_mac(extsbox: @mut SyntaxEnv,
@@ -241,22 +216,23 @@ pub fn expand_item_mac(extsbox: @mut SyntaxEnv,
         _ => cx.span_bug(it.span, "invalid item macro invocation")
     };
 
-    let extname = cx.parse_sess().interner.get(pth.idents[0]);
-    let expanded = match (*extsbox).find(&extname) {
+    let extname = &pth.idents[0];
+    let extnamestr = ident_to_str(extname);
+    let expanded = match (*extsbox).find(&extname.name) {
         None => cx.span_fatal(pth.span,
-                              fmt!("macro undefined: '%s!'", *extname)),
+                              fmt!("macro undefined: '%s!'", *extnamestr)),
 
         Some(@SE(NormalTT(ref expand))) => {
             if it.ident != parse::token::special_idents::invalid {
                 cx.span_fatal(pth.span,
                               fmt!("macro %s! expects no ident argument, \
-                                    given '%s'", *extname,
-                                   *cx.parse_sess().interner.get(it.ident)));
+                                    given '%s'", *extnamestr,
+                                   *ident_to_str(&it.ident)));
             }
             cx.bt_push(ExpandedFrom(CallInfo {
                 call_site: it.span,
                 callee: NameAndSpan {
-                    name: copy *extname,
+                    name: copy *extnamestr,
                     span: expand.span
                 }
             }));
@@ -266,29 +242,29 @@ pub fn expand_item_mac(extsbox: @mut SyntaxEnv,
             if it.ident == parse::token::special_idents::invalid {
                 cx.span_fatal(pth.span,
                               fmt!("macro %s! expects an ident argument",
-                                   *extname));
+                                   *extnamestr));
             }
             cx.bt_push(ExpandedFrom(CallInfo {
                 call_site: it.span,
                 callee: NameAndSpan {
-                    name: copy *extname,
+                    name: copy *extnamestr,
                     span: expand.span
                 }
             }));
             ((*expand).expander)(cx, it.span, it.ident, tts)
         }
         _ => cx.span_fatal(
-            it.span, fmt!("%s! is not legal in item position", *extname))
+            it.span, fmt!("%s! is not legal in item position", *extnamestr))
     };
 
     let maybe_it = match expanded {
         MRItem(it) => fld.fold_item(it),
         MRExpr(_) => cx.span_fatal(pth.span,
                                     ~"expr macro in item position: "
-                                    + *extname),
+                                    + *extnamestr),
         MRAny(_, item_maker, _) => item_maker().chain(|i| {fld.fold_item(i)}),
         MRDef(ref mdef) => {
-            extsbox.insert(@/*bad*/ copy mdef.name, @SE((*mdef).ext));
+            insert_macro(*extsbox,intern(mdef.name), @SE((*mdef).ext));
             None
         }
     };
@@ -296,6 +272,23 @@ pub fn expand_item_mac(extsbox: @mut SyntaxEnv,
     return maybe_it;
 }
 
+
+// insert a macro into the innermost frame that doesn't have the
+// macro_escape tag.
+fn insert_macro(exts: SyntaxEnv, name: ast::Name, transformer: @Transformer) {
+    let is_non_escaping_block =
+        |t : &@Transformer| -> bool{
+        match t {
+            &@BlockInfo(BlockInfo {macros_escape:false,_}) => true,
+            &@BlockInfo(BlockInfo {_}) => false,
+            _ => fail!(fmt!("special identifier %? was bound to a non-BlockInfo",
+                            special_block_name))
+        }
+    };
+    exts.insert_into_frame(name,transformer,intern(special_block_name),
+                           is_non_escaping_block)
+}
+
 // expand a stmt
 pub fn expand_stmt(extsbox: @mut SyntaxEnv,
                    cx: @ExtCtxt,
@@ -321,16 +314,17 @@ pub fn expand_stmt(extsbox: @mut SyntaxEnv,
             fmt!("expected macro name without module \
                   separators"));
     }
-    let extname = cx.parse_sess().interner.get(pth.idents[0]);
-    let (fully_expanded, sp) = match (*extsbox).find(&extname) {
+    let extname = &pth.idents[0];
+    let extnamestr = ident_to_str(extname);
+    let (fully_expanded, sp) = match (*extsbox).find(&extname.name) {
         None =>
-            cx.span_fatal(pth.span, fmt!("macro undefined: '%s'", *extname)),
+            cx.span_fatal(pth.span, fmt!("macro undefined: '%s'", *extnamestr)),
 
         Some(@SE(NormalTT(
             SyntaxExpanderTT{expander: exp, span: exp_sp}))) => {
             cx.bt_push(ExpandedFrom(CallInfo {
                 call_site: sp,
-                callee: NameAndSpan { name: copy *extname, span: exp_sp }
+                callee: NameAndSpan { name: copy *extnamestr, span: exp_sp }
             }));
             let expanded = match exp(cx, mac.span, tts) {
                 MRExpr(e) =>
@@ -339,7 +333,7 @@ pub fn expand_stmt(extsbox: @mut SyntaxEnv,
                 MRAny(_,_,stmt_mkr) => stmt_mkr(),
                 _ => cx.span_fatal(
                     pth.span,
-                    fmt!("non-stmt macro in stmt pos: %s", *extname))
+                    fmt!("non-stmt macro in stmt pos: %s", *extnamestr))
             };
 
             //keep going, outside-in
@@ -360,7 +354,7 @@ pub fn expand_stmt(extsbox: @mut SyntaxEnv,
 
         _ => {
             cx.span_fatal(pth.span,
-                          fmt!("'%s' is not a tt-style macro", *extname))
+                          fmt!("'%s' is not a tt-style macro", *extnamestr))
         }
     };
 
@@ -371,7 +365,33 @@ pub fn expand_stmt(extsbox: @mut SyntaxEnv,
 
 }
 
-
+// return a visitor that extracts the pat_ident paths
+// from a given pattern and puts them in a mutable
+// array (passed in to the traversal)
+pub fn new_name_finder() -> @Visitor<@mut ~[ast::ident]> {
+    let default_visitor = visit::default_visitor();
+    @Visitor{
+        visit_pat : |p:@ast::pat,ident_accum:@mut ~[ast::ident],v:visit::vt<@mut ~[ast::ident]>| {
+            match *p {
+                // we found a pat_ident!
+                ast::pat{id:_, node: ast::pat_ident(_,path,ref inner), span:_} => {
+                    match path {
+                        // a path of length one:
+                        @ast::Path{global: false,idents: [id], span:_,rp:_,types:_} =>
+                        ident_accum.push(id),
+                        // I believe these must be enums...
+                        _ => ()
+                    }
+                    // visit optional subpattern of pat_ident:
+                    for inner.each |subpat: &@ast::pat| { (v.visit_pat)(*subpat, ident_accum, v) }
+                }
+                // use the default traversal for non-pat_idents
+                _ => visit::visit_pat(p,ident_accum,v)
+            }
+        },
+        .. *default_visitor
+    }
+}
 
 pub fn expand_block(extsbox: @mut SyntaxEnv,
                     cx: @ExtCtxt,
@@ -380,21 +400,49 @@ pub fn expand_block(extsbox: @mut SyntaxEnv,
                     fld: @ast_fold,
                     orig: @fn(&blk_, span, @ast_fold) -> (blk_, span))
                  -> (blk_, span) {
-    match (*extsbox).find(&@~" block") {
-        // no scope limit on macros in this block, no need
-        // to push an exts frame:
-        Some(@ScopeMacros(false)) => {
-            orig (blk,sp,fld)
-        },
-        // this block should limit the scope of its macros:
-        Some(@ScopeMacros(true)) => {
-            // see note below about treatment of exts table
-            with_exts_frame!(extsbox,orig(blk,sp,fld))
-        },
-        _ => cx.span_bug(sp, "expected ScopeMacros binding for \" block\"")
+    // see note below about treatment of exts table
+    with_exts_frame!(extsbox,false,orig(blk,sp,fld))
+}
+
+
+// get the (innermost) BlockInfo from an exts stack
+fn get_block_info(exts : SyntaxEnv) -> BlockInfo {
+    match exts.find_in_topmost_frame(&intern(special_block_name)) {
+        Some(@BlockInfo(bi)) => bi,
+        _ => fail!(fmt!("special identifier %? was bound to a non-BlockInfo",
+                       @~" block"))
     }
 }
 
+
+// given a mutable list of renames, return a tree-folder that applies those
+// renames.
+fn renames_to_fold(renames : @mut ~[(ast::ident,ast::Name)]) -> @ast_fold {
+    let afp = default_ast_fold();
+    let f_pre = @AstFoldFns {
+        fold_ident: |id,_| {
+            // the individual elements are memoized... it would
+            // also be possible to memoize on the whole list at once.
+            let new_ctxt = renames.foldl(id.ctxt,|ctxt,&(from,to)| {
+                new_rename(from,to,*ctxt)
+            });
+            ast::ident{name:id.name,ctxt:new_ctxt}
+        },
+        .. *afp
+    };
+    make_fold(f_pre)
+}
+
+// perform a bunch of renames
+fn apply_pending_renames(folder : @ast_fold, stmt : ast::stmt) -> @ast::stmt {
+    match folder.fold_stmt(&stmt) {
+        Some(s) => s,
+        None => fail!(fmt!("renaming of stmt produced None"))
+    }
+}
+
+
+
 pub fn new_span(cx: @ExtCtxt, sp: span) -> span {
     /* this discards information in the case of macro-defining macros */
     return span {lo: sp.lo, hi: sp.hi, expn_info: cx.backtrace()};
@@ -663,35 +711,33 @@ pub fn fun_to_ident_folder(f: @fn(ast::ident)->ast::ident) -> @ast_fold{
 
 // update the ctxts in a path to get a rename node
 pub fn new_ident_renamer(from: ast::ident,
-                      to: ast::Name,
-                      table: @mut SCTable) ->
+                      to: ast::Name) ->
     @fn(ast::ident)->ast::ident {
     |id : ast::ident|
     ast::ident{
-        repr: id.repr,
-        ctxt: new_rename(from,to,id.ctxt,table)
+        name: id.name,
+        ctxt: new_rename(from,to,id.ctxt)
     }
 }
 
 
 // update the ctxts in a path to get a mark node
-pub fn new_ident_marker(mark: uint,
-                        table: @mut SCTable) ->
+pub fn new_ident_marker(mark: uint) ->
     @fn(ast::ident)->ast::ident {
     |id : ast::ident|
     ast::ident{
-        repr: id.repr,
-        ctxt: new_mark(mark,id.ctxt,table)
+        name: id.name,
+        ctxt: new_mark(mark,id.ctxt)
     }
 }
 
 // perform resolution (in the MTWT sense) on all of the
 // idents in the tree. This is the final step in expansion.
-pub fn new_ident_resolver(table: @mut SCTable) ->
+pub fn new_ident_resolver() ->
     @fn(ast::ident)->ast::ident {
     |id : ast::ident|
     ast::ident {
-        repr : resolve(id,table),
+        name : resolve(id),
         ctxt : illegal_ctxt
     }
 }
@@ -702,13 +748,17 @@ mod test {
     use super::*;
     use ast;
     use ast::{attribute_, attr_outer, meta_word, empty_ctxt};
-    use ast_util::{new_sctable};
+    use ast_util::{get_sctable};
     use codemap;
     use codemap::spanned;
     use parse;
+    use parse::token::{gensym, intern, get_ident_interner};
+    use print::pprust;
+    use util::parser_testing::{string_to_item, string_to_pat, strs_to_idents};
+    use visit::{mk_vt,Visitor};
+
     use core::io;
     use core::option::{None, Some};
-    use util::parser_testing::{string_to_item_and_sess};
 
     // make sure that fail! is present
     #[test] fn fail_exists_test () {
@@ -812,20 +862,33 @@ mod test {
 
     #[test]
     fn renaming () {
-        let (maybe_item_ast,sess) = string_to_item_and_sess(@~"fn a() -> int { let b = 13; b} ");
+        let maybe_item_ast = string_to_item(@~"fn a() -> int { let b = 13; b }");
         let item_ast = match maybe_item_ast {
             Some(x) => x,
             None => fail!("test case fail")
         };
-        let table = @mut new_sctable();
-        let a_name = 100; // enforced by testing_interner
-        let a2_name = sess.interner.gensym("a2").repr;
-        let renamer = new_ident_renamer(ast::ident{repr:a_name,ctxt:empty_ctxt},
-                                        a2_name,table);
+        let a_name = intern("a");
+        let a2_name = intern("a2");
+        let renamer = new_ident_renamer(ast::ident{name:a_name,ctxt:empty_ctxt},
+                                        a2_name);
         let renamed_ast = fun_to_ident_folder(renamer).fold_item(item_ast).get();
-        let resolver = new_ident_resolver(table);
+        let resolver = new_ident_resolver();
         let resolved_ast = fun_to_ident_folder(resolver).fold_item(renamed_ast).get();
-        io::print(fmt!("ast: %?\n",resolved_ast))
+        let resolved_as_str = pprust::item_to_str(resolved_ast,
+                                                  get_ident_interner());
+        assert_eq!(resolved_as_str,~"fn a2() -> int { let b = 13; b }");
+
+
     }
 
+    // sigh... it looks like I have two different renaming mechanisms, now...
+
+    #[test]
+    fn pat_idents(){
+        let pat = string_to_pat(@~"(a,Foo{x:c @ (b,9),y:Bar(4,d)})");
+        let pat_idents = new_name_finder();
+        let idents = @mut ~[];
+        ((*pat_idents).visit_pat)(pat,idents, mk_vt(pat_idents));
+        assert_eq!(idents,@mut strs_to_idents(~["a","c","b","d"]));
+    }
 }
diff --git a/src/libsyntax/ext/fmt.rs b/src/libsyntax/ext/fmt.rs
index 65b29ecaa91..67d3f84d1ff 100644
--- a/src/libsyntax/ext/fmt.rs
+++ b/src/libsyntax/ext/fmt.rs
@@ -25,6 +25,7 @@ use ext::build::AstBuilder;
 use core::option;
 use core::unstable::extfmt::ct::*;
 use core::vec;
+use parse::token::{str_to_ident};
 
 pub fn expand_syntax_ext(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
     -> base::MacResult {
@@ -53,12 +54,11 @@ fn pieces_to_expr(cx: @ExtCtxt, sp: span,
                   pieces: ~[Piece], args: ~[@ast::expr])
    -> @ast::expr {
     fn make_path_vec(cx: @ExtCtxt, ident: &str) -> ~[ast::ident] {
-        let intr = cx.parse_sess().interner;
-        return ~[intr.intern("std"),
-                 intr.intern("unstable"),
-                 intr.intern("extfmt"),
-                 intr.intern("rt"),
-                 intr.intern(ident)];
+        return ~[str_to_ident("std"),
+                 str_to_ident("unstable"),
+                 str_to_ident("extfmt"),
+                 str_to_ident("rt"),
+                 str_to_ident(ident)];
     }
     fn make_rt_path_expr(cx: @ExtCtxt, sp: span, nm: &str) -> @ast::expr {
         let path = make_path_vec(cx, nm);
@@ -112,15 +112,14 @@ fn pieces_to_expr(cx: @ExtCtxt, sp: span,
         fn make_conv_struct(cx: @ExtCtxt, sp: span, flags_expr: @ast::expr,
                          width_expr: @ast::expr, precision_expr: @ast::expr,
                          ty_expr: @ast::expr) -> @ast::expr {
-            let intr = cx.parse_sess().interner;
             cx.expr_struct(
                 sp,
                 cx.path_global(sp, make_path_vec(cx, "Conv")),
                 ~[
-                    cx.field_imm(sp, intr.intern("flags"), flags_expr),
-                    cx.field_imm(sp, intr.intern("width"), width_expr),
-                    cx.field_imm(sp, intr.intern("precision"), precision_expr),
-                    cx.field_imm(sp, intr.intern("ty"), ty_expr)
+                    cx.field_imm(sp, str_to_ident("flags"), flags_expr),
+                    cx.field_imm(sp, str_to_ident("width"), width_expr),
+                    cx.field_imm(sp, str_to_ident("precision"), precision_expr),
+                    cx.field_imm(sp, str_to_ident("ty"), ty_expr)
                 ]
             )
         }
@@ -255,11 +254,11 @@ fn pieces_to_expr(cx: @ExtCtxt, sp: span,
     let nargs = args.len();
 
     /* 'ident' is the local buffer building up the result of fmt! */
-    let ident = cx.parse_sess().interner.intern("__fmtbuf");
+    let ident = str_to_ident("__fmtbuf");
     let buf = || cx.expr_ident(fmt_sp, ident);
-    let core_ident = cx.parse_sess().interner.intern("std");
-    let str_ident = cx.parse_sess().interner.intern("str");
-    let push_ident = cx.parse_sess().interner.intern("push_str");
+    let core_ident = str_to_ident("std");
+    let str_ident = str_to_ident("str");
+    let push_ident = str_to_ident("push_str");
     let mut stms = ~[];
 
     /* Translate each piece (portion of the fmt expression) by invoking the
diff --git a/src/libsyntax/ext/log_syntax.rs b/src/libsyntax/ext/log_syntax.rs
index 598537c97e8..3ad4f87083f 100644
--- a/src/libsyntax/ext/log_syntax.rs
+++ b/src/libsyntax/ext/log_syntax.rs
@@ -15,6 +15,7 @@ use codemap;
 use ext::base::*;
 use ext::base;
 use print;
+use parse::token::{get_ident_interner};
 
 use core::io;
 use core::vec;
@@ -28,7 +29,7 @@ pub fn expand_syntax_ext(cx: @ExtCtxt,
     io::stdout().write_line(
         print::pprust::tt_to_str(
             ast::tt_delim(vec::to_owned(tt)),
-            cx.parse_sess().interner));
+            get_ident_interner()));
 
     //trivial expression
     MRExpr(@ast::expr {
diff --git a/src/libsyntax/ext/pipes/mod.rs b/src/libsyntax/ext/pipes/mod.rs
index 46de21d1c0b..3f4b5ee54f1 100644
--- a/src/libsyntax/ext/pipes/mod.rs
+++ b/src/libsyntax/ext/pipes/mod.rs
@@ -52,7 +52,6 @@ use ext::pipes::pipec::gen_init;
 use ext::pipes::proto::visit;
 use parse::lexer::{new_tt_reader, reader};
 use parse::parser::Parser;
-
 use core::option::None;
 
 pub mod ast_builder;
@@ -68,7 +67,6 @@ pub fn expand_proto(cx: @ExtCtxt, _sp: span, id: ast::ident,
     let sess = cx.parse_sess();
     let cfg = cx.cfg();
     let tt_rdr = new_tt_reader(copy cx.parse_sess().span_diagnostic,
-                               cx.parse_sess().interner,
                                None,
                                copy tt);
     let rdr = tt_rdr as @reader;
diff --git a/src/libsyntax/ext/pipes/parse_proto.rs b/src/libsyntax/ext/pipes/parse_proto.rs
index 67ef3347ff7..a89fd26df4c 100644
--- a/src/libsyntax/ext/pipes/parse_proto.rs
+++ b/src/libsyntax/ext/pipes/parse_proto.rs
@@ -17,6 +17,7 @@ use ext::pipes::proto::*;
 use parse::common::SeqSep;
 use parse::parser;
 use parse::token;
+use parse::token::{interner_get};
 
 pub trait proto_parser {
     fn parse_proto(&self, id: ~str) -> protocol;
@@ -42,11 +43,11 @@ impl proto_parser for parser::Parser {
 
     fn parse_state(&self, proto: protocol) {
         let id = self.parse_ident();
-        let name = copy *self.interner.get(id);
+        let name = copy *interner_get(id.name);
 
         self.expect(&token::COLON);
         let dir = match copy *self.token {
-            token::IDENT(n, _) => self.interner.get(n),
+            token::IDENT(n, _) => interner_get(n.name),
             _ => fail!()
         };
         self.bump();
@@ -77,7 +78,7 @@ impl proto_parser for parser::Parser {
     }
 
     fn parse_message(&self, state: state) {
-        let mname = copy *self.interner.get(self.parse_ident());
+        let mname = copy *interner_get(self.parse_ident().name);
 
         let args = if *self.token == token::LPAREN {
             self.parse_unspanned_seq(
@@ -96,7 +97,7 @@ impl proto_parser for parser::Parser {
 
         let next = match *self.token {
           token::IDENT(_, _) => {
-            let name = copy *self.interner.get(self.parse_ident());
+            let name = copy *interner_get(self.parse_ident().name);
             let ntys = if *self.token == token::LT {
                 self.parse_unspanned_seq(
                     &token::LT,
diff --git a/src/libsyntax/ext/pipes/pipec.rs b/src/libsyntax/ext/pipes/pipec.rs
index 83cafcd8a6a..1e5b3c3ee7e 100644
--- a/src/libsyntax/ext/pipes/pipec.rs
+++ b/src/libsyntax/ext/pipes/pipec.rs
@@ -325,10 +325,10 @@ impl gen_init for protocol {
 
         cx.parse_item(fmt!("pub fn init%s() -> (server::%s, client::%s)\
                             { pub use std::pipes::HasBuffer; %s }",
-                           start_state.generics.to_source(cx),
-                           start_state.to_ty(cx).to_source(cx),
-                           start_state.to_ty(cx).to_source(cx),
-                           body.to_source(cx)))
+                           start_state.generics.to_source(),
+                           start_state.to_ty(cx).to_source(),
+                           start_state.to_ty(cx).to_source(),
+                           body.to_source()))
     }
 
     fn gen_buffer_init(&self, ext_cx: @ExtCtxt) -> @ast::expr {
diff --git a/src/libsyntax/ext/quote.rs b/src/libsyntax/ext/quote.rs
index 9182b99bf30..062532afef8 100644
--- a/src/libsyntax/ext/quote.rs
+++ b/src/libsyntax/ext/quote.rs
@@ -63,11 +63,11 @@ pub mod rt {
 
     trait ToSource : ToTokens {
         // Takes a thing and generates a string containing rust code for it.
-        pub fn to_source(cx: @ExtCtxt) -> ~str;
+        pub fn to_source() -> ~str;
 
         // If you can make source, you can definitely make tokens.
         pub fn to_tokens(cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
@@ -75,80 +75,80 @@ pub mod rt {
 
     pub trait ToSource {
         // Takes a thing and generates a string containing rust code for it.
-        pub fn to_source(&self, cx: @ExtCtxt) -> ~str;
+        pub fn to_source(&self) -> ~str;
     }
 
     impl ToSource for ast::ident {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            copy *cx.parse_sess().interner.get(*self)
+        fn to_source(&self) -> ~str {
+            copy *ident_to_str(self)
         }
     }
 
     impl ToSource for @ast::item {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            item_to_str(*self, cx.parse_sess().interner)
+        fn to_source(&self) -> ~str {
+            item_to_str(*self, get_ident_interner())
         }
     }
 
     impl<'self> ToSource for &'self [@ast::item] {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            str::connect(self.map(|i| i.to_source(cx)), "\n\n")
+        fn to_source(&self) -> ~str {
+            str::connect(self.map(|i| i.to_source()), ~"\n\n")
         }
     }
 
     impl ToSource for @ast::Ty {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            ty_to_str(*self, cx.parse_sess().interner)
+        fn to_source(&self) -> ~str {
+            ty_to_str(*self, get_ident_interner())
         }
     }
 
     impl<'self> ToSource for &'self [@ast::Ty] {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            str::connect(self.map(|i| i.to_source(cx)), ", ")
+        fn to_source(&self) -> ~str {
+            str::connect(self.map(|i| i.to_source()), ~", ")
         }
     }
 
     impl ToSource for Generics {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            pprust::generics_to_str(self, cx.parse_sess().interner)
+        fn to_source(&self) -> ~str {
+            pprust::generics_to_str(self, get_ident_interner())
         }
     }
 
     impl ToSource for @ast::expr {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            pprust::expr_to_str(*self, cx.parse_sess().interner)
+        fn to_source(&self) -> ~str {
+            pprust::expr_to_str(*self, get_ident_interner())
         }
     }
 
     impl ToSource for ast::blk {
-        fn to_source(&self, cx: @ExtCtxt) -> ~str {
-            pprust::block_to_str(self, cx.parse_sess().interner)
+        fn to_source(&self) -> ~str {
+            pprust::block_to_str(self, get_ident_interner())
         }
     }
 
     impl<'self> ToSource for &'self str {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_str(@str::to_owned(*self)));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for int {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_int(*self as i64, ast::ty_i));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for i8 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_int(*self as i64, ast::ty_i8));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for i16 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_int(*self as i64, ast::ty_i16));
             pprust::lit_to_str(@lit)
         }
@@ -156,49 +156,49 @@ pub mod rt {
 
 
     impl ToSource for i32 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_int(*self as i64, ast::ty_i32));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for i64 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_int(*self as i64, ast::ty_i64));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for uint {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_uint(*self as u64, ast::ty_u));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for u8 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_uint(*self as u64, ast::ty_u8));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for u16 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_uint(*self as u64, ast::ty_u16));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for u32 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_uint(*self as u64, ast::ty_u32));
             pprust::lit_to_str(@lit)
         }
     }
 
     impl ToSource for u64 {
-        fn to_source(&self, _cx: @ExtCtxt) -> ~str {
+        fn to_source(&self) -> ~str {
             let lit = dummy_spanned(ast::lit_uint(*self as u64, ast::ty_u64));
             pprust::lit_to_str(@lit)
         }
@@ -208,115 +208,115 @@ pub mod rt {
 
     impl ToTokens for ast::ident {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for @ast::item {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl<'self> ToTokens for &'self [@ast::item] {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for @ast::Ty {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl<'self> ToTokens for &'self [@ast::Ty] {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for Generics {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for @ast::expr {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for ast::blk {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl<'self> ToTokens for &'self str {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for int {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for i8 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for i16 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for i32 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for i64 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for uint {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for u8 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for u16 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for u32 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
     impl ToTokens for u64 {
         fn to_tokens(&self, cx: @ExtCtxt) -> ~[token_tree] {
-            cx.parse_tts(self.to_source(cx))
+            cx.parse_tts(self.to_source())
         }
     }
 
@@ -417,25 +417,25 @@ pub fn expand_quote_stmt(cx: @ExtCtxt,
                                     ~[e_attrs], tts))
 }
 
-fn ids_ext(cx: @ExtCtxt, strs: ~[~str]) -> ~[ast::ident] {
-    strs.map(|str| cx.parse_sess().interner.intern(*str))
+fn ids_ext(strs: ~[~str]) -> ~[ast::ident] {
+    strs.map(|str| str_to_ident(*str))
 }
 
-fn id_ext(cx: @ExtCtxt, str: &str) -> ast::ident {
-    cx.parse_sess().interner.intern(str)
+fn id_ext(str: &str) -> ast::ident {
+    str_to_ident(str)
 }
 
 // Lift an ident to the expr that evaluates to that ident.
 fn mk_ident(cx: @ExtCtxt, sp: span, ident: ast::ident) -> @ast::expr {
     let e_str = cx.expr_str(sp, cx.str_of(ident));
     cx.expr_method_call(sp,
-                        cx.expr_ident(sp, id_ext(cx, "ext_cx")),
-                        id_ext(cx, "ident_of"),
+                        cx.expr_ident(sp, id_ext("ext_cx")),
+                        id_ext("ident_of"),
                         ~[e_str])
 }
 
 fn mk_bytepos(cx: @ExtCtxt, sp: span, bpos: BytePos) -> @ast::expr {
-    let path = id_ext(cx, "BytePos");
+    let path = id_ext("BytePos");
     let arg = cx.expr_uint(sp, bpos.to_uint());
     cx.expr_call_ident(sp, path, ~[arg])
 }
@@ -453,7 +453,7 @@ fn mk_binop(cx: @ExtCtxt, sp: span, bop: token::binop) -> @ast::expr {
         SHL => "SHL",
         SHR => "SHR"
     };
-    cx.expr_ident(sp, id_ext(cx, name))
+    cx.expr_ident(sp, id_ext(name))
 }
 
 fn mk_token(cx: @ExtCtxt, sp: span, tok: &token::Token) -> @ast::expr {
@@ -461,12 +461,12 @@ fn mk_token(cx: @ExtCtxt, sp: span, tok: &token::Token) -> @ast::expr {
     match *tok {
         BINOP(binop) => {
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "BINOP"),
+                                      id_ext("BINOP"),
                                       ~[mk_binop(cx, sp, binop)]);
         }
         BINOPEQ(binop) => {
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "BINOPEQ"),
+                                      id_ext("BINOPEQ"),
                                       ~[mk_binop(cx, sp, binop)]);
         }
 
@@ -479,12 +479,12 @@ fn mk_token(cx: @ExtCtxt, sp: span, tok: &token::Token) -> @ast::expr {
                 ast::ty_i32 => ~"ty_i32",
                 ast::ty_i64 => ~"ty_i64"
             };
-            let e_ity = cx.expr_ident(sp, id_ext(cx, s_ity));
+            let e_ity = cx.expr_ident(sp, id_ext(s_ity));
 
             let e_i64 = cx.expr_lit(sp, ast::lit_int(i, ast::ty_i64));
 
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "LIT_INT"),
+                                      id_ext("LIT_INT"),
                                       ~[e_i64, e_ity]);
         }
 
@@ -496,12 +496,12 @@ fn mk_token(cx: @ExtCtxt, sp: span, tok: &token::Token) -> @ast::expr {
                 ast::ty_u32 => ~"ty_u32",
                 ast::ty_u64 => ~"ty_u64"
             };
-            let e_uty = cx.expr_ident(sp, id_ext(cx, s_uty));
+            let e_uty = cx.expr_ident(sp, id_ext(s_uty));
 
             let e_u64 = cx.expr_lit(sp, ast::lit_uint(u, ast::ty_u64));
 
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "LIT_UINT"),
+                                      id_ext("LIT_UINT"),
                                       ~[e_u64, e_uty]);
         }
 
@@ -509,7 +509,7 @@ fn mk_token(cx: @ExtCtxt, sp: span, tok: &token::Token) -> @ast::expr {
             let e_i64 = cx.expr_lit(sp, ast::lit_int(i, ast::ty_i64));
 
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "LIT_INT_UNSUFFIXED"),
+                                      id_ext("LIT_INT_UNSUFFIXED"),
                                       ~[e_i64]);
         }
 
@@ -519,37 +519,37 @@ fn mk_token(cx: @ExtCtxt, sp: span, tok: &token::Token) -> @ast::expr {
                 ast::ty_f32 => ~"ty_f32",
                 ast::ty_f64 => ~"ty_f64"
             };
-            let e_fty = cx.expr_ident(sp, id_ext(cx, s_fty));
+            let e_fty = cx.expr_ident(sp, id_ext(s_fty));
 
             let e_fident = mk_ident(cx, sp, fident);
 
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "LIT_FLOAT"),
+                                      id_ext("LIT_FLOAT"),
                                       ~[e_fident, e_fty]);
         }
 
         LIT_STR(ident) => {
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "LIT_STR"),
+                                      id_ext("LIT_STR"),
                                       ~[mk_ident(cx, sp, ident)]);
         }
 
         IDENT(ident, b) => {
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "IDENT"),
+                                      id_ext("IDENT"),
                                       ~[mk_ident(cx, sp, ident),
                                         cx.expr_bool(sp, b)]);
         }
 
         LIFETIME(ident) => {
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "LIFETIME"),
+                                      id_ext("LIFETIME"),
                                       ~[mk_ident(cx, sp, ident)]);
         }
 
         DOC_COMMENT(ident) => {
             return cx.expr_call_ident(sp,
-                                      id_ext(cx, "DOC_COMMENT"),
+                                      id_ext("DOC_COMMENT"),
                                       ~[mk_ident(cx, sp, ident)]);
         }
 
@@ -593,7 +593,7 @@ fn mk_token(cx: @ExtCtxt, sp: span, tok: &token::Token) -> @ast::expr {
         EOF => "EOF",
         _ => fail!()
     };
-    cx.expr_ident(sp, id_ext(cx, name))
+    cx.expr_ident(sp, id_ext(name))
 }
 
 
@@ -603,14 +603,14 @@ fn mk_tt(cx: @ExtCtxt, sp: span, tt: &ast::token_tree)
     match *tt {
 
         ast::tt_tok(sp, ref tok) => {
-            let e_sp = cx.expr_ident(sp, id_ext(cx, "sp"));
+            let e_sp = cx.expr_ident(sp, id_ext("sp"));
             let e_tok = cx.expr_call_ident(sp,
-                                           id_ext(cx, "tt_tok"),
+                                           id_ext("tt_tok"),
                                            ~[e_sp, mk_token(cx, sp, tok)]);
             let e_push =
                 cx.expr_method_call(sp,
-                                    cx.expr_ident(sp, id_ext(cx, "tt")),
-                                    id_ext(cx, "push"),
+                                    cx.expr_ident(sp, id_ext("tt")),
+                                    id_ext("push"),
                                     ~[e_tok]);
             ~[cx.stmt_expr(e_push)]
         }
@@ -625,13 +625,13 @@ fn mk_tt(cx: @ExtCtxt, sp: span, tt: &ast::token_tree)
             let e_to_toks =
                 cx.expr_method_call(sp,
                                     cx.expr_ident(sp, ident),
-                                    id_ext(cx, "to_tokens"),
-                                    ~[cx.expr_ident(sp, id_ext(cx, "ext_cx"))]);
+                                    id_ext("to_tokens"),
+                                    ~[cx.expr_ident(sp, id_ext("ext_cx"))]);
 
             let e_push =
                 cx.expr_method_call(sp,
-                                    cx.expr_ident(sp, id_ext(cx, "tt")),
-                                    id_ext(cx, "push_all_move"),
+                                    cx.expr_ident(sp, id_ext("tt")),
+                                    id_ext("push_all_move"),
                                     ~[e_to_toks]);
 
             ~[cx.stmt_expr(e_push)]
@@ -671,10 +671,10 @@ fn expand_tts(cx: @ExtCtxt,
     // import the runtime module, followed by a tt-building expression.
 
     let uses = ~[ cx.view_use_glob(sp, ast::public,
-                                   ids_ext(cx, ~[~"syntax",
-                                                 ~"ext",
-                                                 ~"quote",
-                                                 ~"rt"])) ];
+                                   ids_ext(~[~"syntax",
+                                             ~"ext",
+                                             ~"quote",
+                                             ~"rt"])) ];
 
     // We also bind a single value, sp, to ext_cx.call_site()
     //
@@ -703,23 +703,23 @@ fn expand_tts(cx: @ExtCtxt,
     // worth the hassle.
 
     let e_sp = cx.expr_method_call(sp,
-                                   cx.expr_ident(sp, id_ext(cx, "ext_cx")),
-                                   id_ext(cx, "call_site"),
+                                   cx.expr_ident(sp, id_ext("ext_cx")),
+                                   id_ext("call_site"),
                                    ~[]);
 
     let stmt_let_sp = cx.stmt_let(sp, false,
-                                  id_ext(cx, "sp"),
+                                  id_ext("sp"),
                                   e_sp);
 
     let stmt_let_tt = cx.stmt_let(sp, true,
-                                  id_ext(cx, "tt"),
+                                  id_ext("tt"),
                                   cx.expr_vec_uniq(sp, ~[]));
 
     cx.expr_blk(
         cx.blk_all(sp, uses,
                    ~[stmt_let_sp,
                      stmt_let_tt] + mk_tts(cx, sp, tts),
-                   Some(cx.expr_ident(sp, id_ext(cx, "tt")))))
+                   Some(cx.expr_ident(sp, id_ext("tt")))))
 }
 
 fn expand_parse_call(cx: @ExtCtxt,
@@ -730,25 +730,25 @@ fn expand_parse_call(cx: @ExtCtxt,
     let tts_expr = expand_tts(cx, sp, tts);
 
     let cfg_call = || cx.expr_method_call(
-        sp, cx.expr_ident(sp, id_ext(cx, "ext_cx")),
-        id_ext(cx, "cfg"), ~[]);
+        sp, cx.expr_ident(sp, id_ext("ext_cx")),
+        id_ext("cfg"), ~[]);
 
     let parse_sess_call = || cx.expr_method_call(
-        sp, cx.expr_ident(sp, id_ext(cx, "ext_cx")),
-        id_ext(cx, "parse_sess"), ~[]);
+        sp, cx.expr_ident(sp, id_ext("ext_cx")),
+        id_ext("parse_sess"), ~[]);
 
     let new_parser_call =
         cx.expr_call_global(sp,
-                            ids_ext(cx, ~[~"syntax",
-                                          ~"ext",
-                                          ~"quote",
-                                          ~"rt",
-                                          ~"new_parser_from_tts"]),
+                            ids_ext(~[~"syntax",
+                                      ~"ext",
+                                      ~"quote",
+                                      ~"rt",
+                                      ~"new_parser_from_tts"]),
                             ~[parse_sess_call(),
                               cfg_call(),
                               tts_expr]);
 
     cx.expr_method_call(sp, new_parser_call,
-                        id_ext(cx, parse_method),
+                        id_ext(parse_method),
                         arg_exprs)
 }
diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 91fad0c22a6..fcdfb0a6ba7 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -18,6 +18,7 @@ use ext::base::*;
 use ext::base;
 use ext::build::AstBuilder;
 use parse;
+use parse::token::{get_ident_interner};
 use print::pprust;
 
 use core::io;
@@ -65,7 +66,7 @@ pub fn expand_file(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
 
 pub fn expand_stringify(cx: @ExtCtxt, sp: span, tts: &[ast::token_tree])
     -> base::MacResult {
-    let s = pprust::tts_to_str(tts, cx.parse_sess().interner);
+    let s = pprust::tts_to_str(tts, get_ident_interner());
     base::MRExpr(cx.expr_str(sp, s))
 }
 
diff --git a/src/libsyntax/ext/trace_macros.rs b/src/libsyntax/ext/trace_macros.rs
index 111e176d4c5..3baf432f24d 100644
--- a/src/libsyntax/ext/trace_macros.rs
+++ b/src/libsyntax/ext/trace_macros.rs
@@ -28,7 +28,6 @@ pub fn expand_trace_macros(cx: @ExtCtxt,
     let cfg = cx.cfg();
     let tt_rdr = new_tt_reader(
         copy cx.parse_sess().span_diagnostic,
-        cx.parse_sess().interner,
         None,
         vec::to_owned(tt)
     );
diff --git a/src/libsyntax/ext/tt/macro_parser.rs b/src/libsyntax/ext/tt/macro_parser.rs
index ec63b5a7f74..9fb9def84e9 100644
--- a/src/libsyntax/ext/tt/macro_parser.rs
+++ b/src/libsyntax/ext/tt/macro_parser.rs
@@ -19,7 +19,7 @@ use codemap;
 use parse::lexer::*; //resolve bug?
 use parse::ParseSess;
 use parse::parser::Parser;
-use parse::token::{Token, EOF, to_str, nonterminal};
+use parse::token::{Token, EOF, to_str, nonterminal, get_ident_interner, ident_to_str};
 use parse::token;
 
 use core::hashmap::HashMap;
@@ -201,13 +201,13 @@ pub fn nameize(p_s: @mut ParseSess, ms: &[matcher], res: &[@named_match])
             };
           }
           codemap::spanned {
-                node: match_nonterminal(bind_name, _, idx), span: sp
+                node: match_nonterminal(ref bind_name, _, idx), span: sp
           } => {
-            if ret_val.contains_key(&bind_name) {
+            if ret_val.contains_key(bind_name) {
                 p_s.span_diagnostic.span_fatal(sp, ~"Duplicated bind name: "+
-                                               *p_s.interner.get(bind_name))
+                                               *ident_to_str(bind_name))
             }
-            ret_val.insert(bind_name, res[idx]);
+            ret_val.insert(*bind_name, res[idx]);
           }
         }
     }
@@ -372,9 +372,9 @@ pub fn parse(
                 || bb_eis.len() > 1u {
                 let nts = str::connect(vec::map(bb_eis, |ei| {
                     match ei.elts[ei.idx].node {
-                      match_nonterminal(bind,name,_) => {
-                        fmt!("%s ('%s')", *sess.interner.get(name),
-                             *sess.interner.get(bind))
+                      match_nonterminal(ref bind,ref name,_) => {
+                        fmt!("%s ('%s')", *ident_to_str(name),
+                             *ident_to_str(bind))
                       }
                       _ => fail!()
                     } }), " or ");
@@ -384,7 +384,7 @@ pub fn parse(
                     nts, next_eis.len()));
             } else if (bb_eis.len() == 0u && next_eis.len() == 0u) {
                 return failure(sp, ~"No rules expected the token: "
-                            + to_str(rdr.interner(), &tok));
+                            + to_str(get_ident_interner(), &tok));
             } else if (next_eis.len() > 0u) {
                 /* Now process the next token */
                 while(next_eis.len() > 0u) {
@@ -396,9 +396,9 @@ pub fn parse(
 
                 let mut ei = bb_eis.pop();
                 match ei.elts[ei.idx].node {
-                  match_nonterminal(_, name, idx) => {
+                  match_nonterminal(_, ref name, idx) => {
                     ei.matches[idx].push(@matched_nonterminal(
-                        parse_nt(&rust_parser, *sess.interner.get(name))));
+                        parse_nt(&rust_parser, *ident_to_str(name))));
                     ei.idx += 1u;
                   }
                   _ => fail!()
@@ -430,7 +430,7 @@ pub fn parse_nt(p: &Parser, name: &str) -> nonterminal {
       "ident" => match *p.token {
         token::IDENT(sn,b) => { p.bump(); token::nt_ident(sn,b) }
         _ => p.fatal(~"expected ident, found "
-                     + token::to_str(p.reader.interner(), &copy *p.token))
+                     + token::to_str(get_ident_interner(), &copy *p.token))
       },
       "path" => token::nt_path(p.parse_path_with_tps(false)),
       "tt" => {
diff --git a/src/libsyntax/ext/tt/macro_rules.rs b/src/libsyntax/ext/tt/macro_rules.rs
index 261943132b3..1822117507d 100644
--- a/src/libsyntax/ext/tt/macro_rules.rs
+++ b/src/libsyntax/ext/tt/macro_rules.rs
@@ -21,7 +21,7 @@ use ext::tt::macro_parser::{named_match, matched_seq, matched_nonterminal};
 use ext::tt::macro_parser::{parse, parse_or_else, success, failure};
 use parse::lexer::{new_tt_reader, reader};
 use parse::parser::Parser;
-use parse::token::special_idents;
+use parse::token::{get_ident_interner, special_idents, gensym_ident, ident_to_str};
 use parse::token::{FAT_ARROW, SEMI, nt_matchers, nt_tt};
 use print;
 
@@ -38,8 +38,8 @@ pub fn add_new_extension(cx: @ExtCtxt,
         spanned { node: copy m, span: dummy_sp() }
     }
 
-    let lhs_nm =  cx.parse_sess().interner.gensym("lhs");
-    let rhs_nm =  cx.parse_sess().interner.gensym("rhs");
+    let lhs_nm =  gensym_ident("lhs");
+    let rhs_nm =  gensym_ident("rhs");
 
     // The grammar for macro_rules! is:
     // $( $lhs:mtcs => $rhs:tt );+
@@ -57,7 +57,7 @@ pub fn add_new_extension(cx: @ExtCtxt,
 
     // Parse the macro_rules! invocation (`none` is for no interpolations):
     let arg_reader = new_tt_reader(copy cx.parse_sess().span_diagnostic,
-                                   cx.parse_sess().interner, None, copy arg);
+                                   None, copy arg);
     let argument_map = parse_or_else(cx.parse_sess(),
                                      cx.cfg(),
                                      arg_reader as @reader,
@@ -85,7 +85,7 @@ pub fn add_new_extension(cx: @ExtCtxt,
                              cx.str_of(name),
                              print::pprust::tt_to_str(
                                  ast::tt_delim(vec::to_owned(arg)),
-                                 cx.parse_sess().interner)));
+                                 get_ident_interner())));
         }
 
         // Which arm's failure should we report? (the one furthest along)
@@ -93,7 +93,6 @@ pub fn add_new_extension(cx: @ExtCtxt,
         let mut best_fail_msg = ~"internal error: ran no matchers";
 
         let s_d = cx.parse_sess().span_diagnostic;
-        let itr = cx.parse_sess().interner;
 
         for lhses.eachi |i, lhs| { // try each arm's matchers
             match *lhs {
@@ -101,7 +100,6 @@ pub fn add_new_extension(cx: @ExtCtxt,
                 // `none` is because we're not interpolating
                 let arg_rdr = new_tt_reader(
                     s_d,
-                    itr,
                     None,
                     vec::to_owned(arg)
                 ) as @reader;
@@ -122,7 +120,7 @@ pub fn add_new_extension(cx: @ExtCtxt,
                         _ => cx.span_bug(sp, "bad thing in rhs")
                     };
                     // rhs has holes ( `$id` and `$(...)` that need filled)
-                    let trncbr = new_tt_reader(s_d, itr, Some(named_matches),
+                    let trncbr = new_tt_reader(s_d, Some(named_matches),
                                                rhs);
                     let p = @Parser(cx.parse_sess(),
                                     cx.cfg(),
@@ -151,7 +149,7 @@ pub fn add_new_extension(cx: @ExtCtxt,
         |cx, sp, arg| generic_extension(cx, sp, name, arg, *lhses, *rhses);
 
     return MRDef(MacroDef{
-        name: copy *cx.parse_sess().interner.get(name),
+        name: copy *ident_to_str(&name),
         ext: NormalTT(base::SyntaxExpanderTT{expander: exp, span: Some(sp)})
     });
 }
diff --git a/src/libsyntax/ext/tt/transcribe.rs b/src/libsyntax/ext/tt/transcribe.rs
index 4a6a070df50..f0b078603db 100644
--- a/src/libsyntax/ext/tt/transcribe.rs
+++ b/src/libsyntax/ext/tt/transcribe.rs
@@ -15,7 +15,8 @@ use ast::{token_tree, tt_delim, tt_tok, tt_seq, tt_nonterminal,ident};
 use codemap::{span, dummy_sp};
 use diagnostic::span_handler;
 use ext::tt::macro_parser::{named_match, matched_seq, matched_nonterminal};
-use parse::token::{EOF, INTERPOLATED, IDENT, Token, nt_ident, ident_interner};
+use parse::token::{EOF, INTERPOLATED, IDENT, Token, nt_ident};
+use parse::token::{ident_to_str};
 use parse::lexer::TokenAndSpan;
 
 use core::hashmap::HashMap;
@@ -33,7 +34,6 @@ struct TtFrame {
 
 pub struct TtReader {
     sp_diag: @span_handler,
-    interner: @ident_interner,
     // the unzipped tree:
     stack: @mut TtFrame,
     /* for MBE-style macro transcription */
@@ -49,13 +49,11 @@ pub struct TtReader {
  *  `src` contains no `tt_seq`s and `tt_nonterminal`s, `interp` can (and
  *  should) be none. */
 pub fn new_tt_reader(sp_diag: @span_handler,
-                     itr: @ident_interner,
                      interp: Option<HashMap<ident,@named_match>>,
                      src: ~[ast::token_tree])
                   -> @mut TtReader {
     let r = @mut TtReader {
         sp_diag: sp_diag,
-        interner: itr,
         stack: @mut TtFrame {
             forest: @mut src,
             idx: 0u,
@@ -93,7 +91,6 @@ fn dup_tt_frame(f: @mut TtFrame) -> @mut TtFrame {
 pub fn dup_tt_reader(r: @mut TtReader) -> @mut TtReader {
     @mut TtReader {
         sp_diag: r.sp_diag,
-        interner: r.interner,
         stack: dup_tt_frame(r.stack),
         repeat_idx: copy r.repeat_idx,
         repeat_len: copy r.repeat_len,
@@ -126,7 +123,7 @@ fn lookup_cur_matched(r: &mut TtReader, name: ident) -> @named_match {
         Some(s) => lookup_cur_matched_by_matched(r, s),
         None => {
             r.sp_diag.span_fatal(r.cur_span, fmt!("unknown macro variable `%s`",
-                                                  *r.interner.get(name)));
+                                                  *ident_to_str(&name)));
         }
     }
 }
@@ -139,13 +136,13 @@ fn lockstep_iter_size(t: &token_tree, r: &mut TtReader) -> lis {
         match lhs {
           lis_unconstrained => copy rhs,
           lis_contradiction(_) => copy lhs,
-          lis_constraint(l_len, l_id) => match rhs {
+          lis_constraint(l_len, ref l_id) => match rhs {
             lis_unconstrained => copy lhs,
             lis_contradiction(_) => copy rhs,
             lis_constraint(r_len, _) if l_len == r_len => copy lhs,
-            lis_constraint(r_len, r_id) => {
-                let l_n = copy *r.interner.get(l_id);
-                let r_n = copy *r.interner.get(r_id);
+            lis_constraint(r_len, ref r_id) => {
+                let l_n = copy *ident_to_str(l_id);
+                let r_n = copy *ident_to_str(r_id);
                 lis_contradiction(fmt!("Inconsistent lockstep iteration: \
                                        '%s' has %u items, but '%s' has %u",
                                         l_n, l_len, r_n, r_len))
@@ -295,7 +292,7 @@ pub fn tt_next_token(r: &mut TtReader) -> TokenAndSpan {
                 r.sp_diag.span_fatal(
                     copy r.cur_span, /* blame the macro writer */
                     fmt!("variable '%s' is still repeating at this depth",
-                         *r.interner.get(ident)));
+                         *ident_to_str(&ident)));
               }
             }
           }
diff --git a/src/libsyntax/parse/comments.rs b/src/libsyntax/parse/comments.rs
index 2f166ae89ef..dab8dd3b4b6 100644
--- a/src/libsyntax/parse/comments.rs
+++ b/src/libsyntax/parse/comments.rs
@@ -18,6 +18,7 @@ use parse::lexer::{StringReader, bump, is_eof, nextch, TokenAndSpan};
 use parse::lexer::{is_line_non_doc_comment, is_block_non_doc_comment};
 use parse::lexer;
 use parse::token;
+use parse::token::{get_ident_interner};
 use parse;
 
 use core::io;
@@ -323,12 +324,9 @@ pub fn gather_comments_and_literals(span_diagnostic:
                                     srdr: @io::Reader)
                                  -> (~[cmnt], ~[lit]) {
     let src = @str::from_bytes(srdr.read_whole_stream());
-    let itr = parse::token::mk_fake_ident_interner();
     let cm = CodeMap::new();
     let filemap = cm.new_filemap(path, src);
-    let rdr = lexer::new_low_level_string_reader(span_diagnostic,
-                                                 filemap,
-                                                 itr);
+    let rdr = lexer::new_low_level_string_reader(span_diagnostic, filemap);
 
     let mut comments: ~[cmnt] = ~[];
     let mut literals: ~[lit] = ~[];
@@ -358,7 +356,7 @@ pub fn gather_comments_and_literals(span_diagnostic:
             debug!("tok lit: %s", s);
             literals.push(lit {lit: s, pos: sp.lo});
         } else {
-            debug!("tok: %s", token::to_str(rdr.interner, &tok));
+            debug!("tok: %s", token::to_str(get_ident_interner(), &tok));
         }
         first_read = false;
     }
diff --git a/src/libsyntax/parse/common.rs b/src/libsyntax/parse/common.rs
index 8a930cf9afd..9fb69821953 100644
--- a/src/libsyntax/parse/common.rs
+++ b/src/libsyntax/parse/common.rs
@@ -16,6 +16,7 @@ use parse::lexer::reader;
 use parse::parser::Parser;
 use parse::token::keywords;
 use parse::token;
+use parse::token::{get_ident_interner};
 
 use opt_vec;
 use opt_vec::OptVec;
@@ -49,13 +50,13 @@ pub fn seq_sep_none() -> SeqSep {
 // maps any token back to a string. not necessary if you know it's
 // an identifier....
 pub fn token_to_str(reader: @reader, token: &token::Token) -> ~str {
-    token::to_str(reader.interner(), token)
+    token::to_str(get_ident_interner(), token)
 }
 
 impl Parser {
     // convert a token to a string using self's reader
     pub fn token_to_str(&self, token: &token::Token) -> ~str {
-        token::to_str(self.reader.interner(), token)
+        token::to_str(get_ident_interner(), token)
     }
 
     // convert the current token to a string using self's reader
@@ -142,7 +143,7 @@ impl Parser {
     // true. Otherwise, return false.
     pub fn eat_keyword(&self, kw: keywords::Keyword) -> bool {
         let is_kw = match *self.token {
-            token::IDENT(sid, false) => kw.to_ident().repr == sid.repr,
+            token::IDENT(sid, false) => kw.to_ident().name == sid.name,
             _ => false
         };
         if is_kw { self.bump() }
diff --git a/src/libsyntax/parse/lexer.rs b/src/libsyntax/parse/lexer.rs
index 0eb933e6c3a..84700f052c9 100644
--- a/src/libsyntax/parse/lexer.rs
+++ b/src/libsyntax/parse/lexer.rs
@@ -17,6 +17,7 @@ use diagnostic::span_handler;
 use ext::tt::transcribe::{tt_next_token};
 use ext::tt::transcribe::{dup_tt_reader};
 use parse::token;
+use parse::token::{str_to_ident};
 
 use core::char;
 use core::either;
@@ -30,7 +31,6 @@ pub trait reader {
     fn next_token(@mut self) -> TokenAndSpan;
     fn fatal(@mut self, ~str) -> !;
     fn span_diag(@mut self) -> @span_handler;
-    fn interner(@mut self) -> @token::ident_interner;
     fn peek(@mut self) -> TokenAndSpan;
     fn dup(@mut self) -> @reader;
 }
@@ -50,25 +50,22 @@ pub struct StringReader {
     // The last character to be read
     curr: char,
     filemap: @codemap::FileMap,
-    interner: @token::ident_interner,
     /* cached: */
     peek_tok: token::Token,
     peek_span: span
 }
 
 pub fn new_string_reader(span_diagnostic: @span_handler,
-                         filemap: @codemap::FileMap,
-                         itr: @token::ident_interner)
+                         filemap: @codemap::FileMap)
                       -> @mut StringReader {
-    let r = new_low_level_string_reader(span_diagnostic, filemap, itr);
+    let r = new_low_level_string_reader(span_diagnostic, filemap);
     string_advance_token(r); /* fill in peek_* */
     return r;
 }
 
 /* For comments.rs, which hackily pokes into 'pos' and 'curr' */
 pub fn new_low_level_string_reader(span_diagnostic: @span_handler,
-                                   filemap: @codemap::FileMap,
-                                   itr: @token::ident_interner)
+                                   filemap: @codemap::FileMap)
                                 -> @mut StringReader {
     // Force the initial reader bump to start on a fresh line
     let initial_char = '\n';
@@ -79,7 +76,6 @@ pub fn new_low_level_string_reader(span_diagnostic: @span_handler,
         col: CharPos(0),
         curr: initial_char,
         filemap: filemap,
-        interner: itr,
         /* dummy values; not read */
         peek_tok: token::EOF,
         peek_span: codemap::dummy_sp()
@@ -100,7 +96,6 @@ fn dup_string_reader(r: @mut StringReader) -> @mut StringReader {
         col: r.col,
         curr: r.curr,
         filemap: r.filemap,
-        interner: r.interner,
         peek_tok: copy r.peek_tok,
         peek_span: copy r.peek_span
     }
@@ -121,7 +116,6 @@ impl reader for StringReader {
         self.span_diagnostic.span_fatal(copy self.peek_span, m)
     }
     fn span_diag(@mut self) -> @span_handler { self.span_diagnostic }
-    fn interner(@mut self) -> @token::ident_interner { self.interner }
     fn peek(@mut self) -> TokenAndSpan {
         TokenAndSpan {
             tok: copy self.peek_tok,
@@ -138,7 +132,6 @@ impl reader for TtReader {
         self.sp_diag.span_fatal(copy self.cur_span, m);
     }
     fn span_diag(@mut self) -> @span_handler { self.sp_diag }
-    fn interner(@mut self) -> @token::ident_interner { self.interner }
     fn peek(@mut self) -> TokenAndSpan {
         TokenAndSpan {
             tok: copy self.cur_tok,
@@ -277,7 +270,7 @@ fn consume_any_line_comment(rdr: @mut StringReader)
                 // but comments with only more "/"s are not
                 if !is_line_non_doc_comment(acc) {
                     return Some(TokenAndSpan{
-                        tok: token::DOC_COMMENT(rdr.interner.intern(acc)),
+                        tok: token::DOC_COMMENT(str_to_ident(acc)),
                         sp: codemap::mk_sp(start_bpos, rdr.pos)
                     });
                 }
@@ -331,7 +324,7 @@ fn consume_block_comment(rdr: @mut StringReader)
             // but comments with only "*"s between two "/"s are not
             if !is_block_non_doc_comment(acc) {
                 return Some(TokenAndSpan{
-                    tok: token::DOC_COMMENT(rdr.interner.intern(acc)),
+                    tok: token::DOC_COMMENT(str_to_ident(acc)),
                     sp: codemap::mk_sp(start_bpos, rdr.pos)
                 });
             }
@@ -477,12 +470,12 @@ fn scan_number(c: char, rdr: @mut StringReader) -> token::Token {
         if c == '3' && n == '2' {
             bump(rdr);
             bump(rdr);
-            return token::LIT_FLOAT(rdr.interner.intern(num_str),
+            return token::LIT_FLOAT(str_to_ident(num_str),
                                  ast::ty_f32);
         } else if c == '6' && n == '4' {
             bump(rdr);
             bump(rdr);
-            return token::LIT_FLOAT(rdr.interner.intern(num_str),
+            return token::LIT_FLOAT(str_to_ident(num_str),
                                  ast::ty_f64);
             /* FIXME (#2252): if this is out of range for either a
             32-bit or 64-bit float, it won't be noticed till the
@@ -494,9 +487,9 @@ fn scan_number(c: char, rdr: @mut StringReader) -> token::Token {
     }
     if is_float {
         if is_machine_float {
-            return token::LIT_FLOAT(rdr.interner.intern(num_str), ast::ty_f);
+            return token::LIT_FLOAT(str_to_ident(num_str), ast::ty_f);
         }
-        return token::LIT_FLOAT_UNSUFFIXED(rdr.interner.intern(num_str));
+        return token::LIT_FLOAT_UNSUFFIXED(str_to_ident(num_str));
     } else {
         if str::len(num_str) == 0u {
             rdr.fatal(~"no valid digits found for number");
@@ -559,7 +552,7 @@ fn next_token_inner(rdr: @mut StringReader) -> token::Token {
         let is_mod_name = c == ':' && nextch(rdr) == ':';
 
         // FIXME: perform NFKC normalization here. (Issue #2253)
-        return token::IDENT(rdr.interner.intern(accum_str), is_mod_name);
+        return token::IDENT(str_to_ident(accum_str), is_mod_name);
     }
     if is_dec_digit(c) {
         return scan_number(c, rdr);
@@ -669,7 +662,7 @@ fn next_token_inner(rdr: @mut StringReader) -> token::Token {
                 lifetime_name.push_char(rdr.curr);
                 bump(rdr);
             }
-            return token::LIFETIME(rdr.interner.intern(lifetime_name));
+            return token::LIFETIME(str_to_ident(lifetime_name));
         }
 
         // Otherwise it is a character constant:
@@ -742,7 +735,7 @@ fn next_token_inner(rdr: @mut StringReader) -> token::Token {
             }
         }
         bump(rdr);
-        return token::LIT_STR(rdr.interner.intern(accum_str));
+        return token::LIT_STR(str_to_ident(accum_str));
       }
       '-' => {
         if nextch(rdr) == '>' {
@@ -786,10 +779,10 @@ mod test {
     use core::option::None;
     use diagnostic;
     use parse::token;
+    use parse::token::{str_to_ident};
 
     // represents a testing reader (incl. both reader and interner)
     struct Env {
-        interner: @token::ident_interner,
         string_reader: @mut StringReader
     }
 
@@ -797,20 +790,18 @@ mod test {
     fn setup(teststr: ~str) -> Env {
         let cm = CodeMap::new();
         let fm = cm.new_filemap(~"zebra.rs", @teststr);
-        let ident_interner = token::get_ident_interner();
         let span_handler =
             diagnostic::mk_span_handler(diagnostic::mk_handler(None),@cm);
         Env {
-            interner: ident_interner,
-            string_reader: new_string_reader(span_handler,fm,ident_interner)
+            string_reader: new_string_reader(span_handler,fm)
         }
     }
 
     #[test] fn t1 () {
-        let Env {interner: ident_interner, string_reader} =
+        let Env {string_reader} =
             setup(~"/* my source file */ \
                     fn main() { io::println(~\"zebra\"); }\n");
-        let id = ident_interner.intern("fn");
+        let id = str_to_ident("fn");
         let tok1 = string_reader.next_token();
         let tok2 = TokenAndSpan{
             tok:token::IDENT(id, false),
@@ -821,7 +812,7 @@ mod test {
         // read another token:
         let tok3 = string_reader.next_token();
         let tok4 = TokenAndSpan{
-            tok:token::IDENT(ident_interner.intern("main"), false),
+            tok:token::IDENT(str_to_ident("main"), false),
             sp:span {lo:BytePos(24),hi:BytePos(28),expn_info: None}};
         assert_eq!(tok3,tok4);
         // the lparen is already read:
@@ -839,39 +830,39 @@ mod test {
     }
 
     // make the identifier by looking up the string in the interner
-    fn mk_ident (env: Env, id: &str, is_mod_name: bool) -> token::Token {
-        token::IDENT (env.interner.intern(id),is_mod_name)
+    fn mk_ident (id: &str, is_mod_name: bool) -> token::Token {
+        token::IDENT (str_to_ident(id),is_mod_name)
     }
 
     #[test] fn doublecolonparsing () {
         let env = setup (~"a b");
         check_tokenization (env,
-                           ~[mk_ident (env,"a",false),
-                             mk_ident (env,"b",false)]);
+                           ~[mk_ident("a",false),
+                             mk_ident("b",false)]);
     }
 
     #[test] fn dcparsing_2 () {
         let env = setup (~"a::b");
         check_tokenization (env,
-                           ~[mk_ident (env,"a",true),
+                           ~[mk_ident("a",true),
                              token::MOD_SEP,
-                             mk_ident (env,"b",false)]);
+                             mk_ident("b",false)]);
     }
 
     #[test] fn dcparsing_3 () {
         let env = setup (~"a ::b");
         check_tokenization (env,
-                           ~[mk_ident (env,"a",false),
+                           ~[mk_ident("a",false),
                              token::MOD_SEP,
-                             mk_ident (env,"b",false)]);
+                             mk_ident("b",false)]);
     }
 
     #[test] fn dcparsing_4 () {
         let env = setup (~"a:: b");
         check_tokenization (env,
-                           ~[mk_ident (env,"a",true),
+                           ~[mk_ident("a",true),
                              token::MOD_SEP,
-                             mk_ident (env,"b",false)]);
+                             mk_ident("b",false)]);
     }
 
     #[test] fn character_a() {
@@ -899,7 +890,7 @@ mod test {
         let env = setup(~"'abc");
         let TokenAndSpan {tok, sp: _} =
             env.string_reader.next_token();
-        let id = env.interner.intern("abc");
+        let id = token::str_to_ident("abc");
         assert_eq!(tok, token::LIFETIME(id));
     }
 
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index 9c716f5631f..d7248204e1c 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -19,7 +19,6 @@ use diagnostic::{span_handler, mk_span_handler, mk_handler, Emitter};
 use parse::attr::parser_attr;
 use parse::lexer::reader;
 use parse::parser::Parser;
-use parse::token::{ident_interner, get_ident_interner};
 
 use core::io;
 use core::option::{None, Option, Some};
@@ -43,14 +42,10 @@ pub mod classify;
 pub mod obsolete;
 
 // info about a parsing session.
-// This structure and the reader both have
-// an interner associated with them. If they're
-// not the same, bad things can happen.
 pub struct ParseSess {
     cm: @codemap::CodeMap, // better be the same as the one in the reader!
     next_id: node_id,
     span_diagnostic: @span_handler, // better be the same as the one in the reader!
-    interner: @ident_interner,
 }
 
 pub fn new_parse_sess(demitter: Option<Emitter>) -> @mut ParseSess {
@@ -59,7 +54,6 @@ pub fn new_parse_sess(demitter: Option<Emitter>) -> @mut ParseSess {
         cm: cm,
         next_id: 1,
         span_diagnostic: mk_span_handler(mk_handler(demitter), cm),
-        interner: get_ident_interner(),
     }
 }
 
@@ -70,7 +64,6 @@ pub fn new_parse_sess_special_handler(sh: @span_handler,
         cm: cm,
         next_id: 1,
         span_diagnostic: sh,
-        interner: get_ident_interner(),
     }
 }
 
@@ -312,9 +305,7 @@ pub fn filemap_to_tts(sess: @mut ParseSess, filemap: @FileMap)
     // it appears to me that the cfg doesn't matter here... indeed,
     // parsing tt's probably shouldn't require a parser at all.
     let cfg = ~[];
-    let srdr = lexer::new_string_reader(copy sess.span_diagnostic,
-                                        filemap,
-                                        sess.interner);
+    let srdr = lexer::new_string_reader(copy sess.span_diagnostic, filemap);
     let p1 = Parser(sess, cfg, srdr as @reader);
     p1.parse_all_token_trees()
 }
@@ -325,7 +316,6 @@ pub fn tts_to_parser(sess: @mut ParseSess,
                      cfg: ast::crate_cfg) -> Parser {
     let trdr = lexer::new_tt_reader(
         copy sess.span_diagnostic,
-        sess.interner,
         None,
         tts
     );
@@ -351,12 +341,13 @@ mod test {
     use codemap::{span, BytePos, spanned};
     use opt_vec;
     use ast;
+    use ast::{new_ident};
     use abi;
     use parse::parser::Parser;
-    use parse::token::intern;
-    use util::parser_testing::{string_to_tts_and_sess,string_to_parser};
+    use parse::token::{intern, str_to_ident};
+    use util::parser_testing::{string_to_tts_and_sess, string_to_parser};
     use util::parser_testing::{string_to_expr, string_to_item};
-    use util::parser_testing::{string_to_stmt};
+    use util::parser_testing::{string_to_stmt, strs_to_idents};
 
     // map a string to tts, return the tt without its parsesess
     fn string_to_tts_only(source_str : @~str) -> ~[ast::token_tree] {
@@ -377,17 +368,12 @@ mod test {
         span{lo:BytePos(a),hi:BytePos(b),expn_info:None}
     }
 
-    // convert a vector of uints to a vector of ast::idents
-    fn ints_to_idents(ids: ~[~str]) -> ~[ast::ident] {
-        ids.map(|u| intern(*u))
-    }
-
     #[test] fn path_exprs_1 () {
         assert_eq!(string_to_expr(@~"a"),
                    @ast::expr{id:1,
                               node:ast::expr_path(@ast::Path {span:sp(0,1),
                                                               global:false,
-                                                              idents:~[intern("a")],
+                                                              idents:~[str_to_ident("a")],
                                                               rp:None,
                                                               types:~[]}),
                               span:sp(0,1)})
@@ -399,7 +385,7 @@ mod test {
                                node:ast::expr_path(
                                    @ast::Path {span:sp(0,6),
                                                global:true,
-                                               idents:ints_to_idents(~[~"a",~"b"]),
+                                               idents:strs_to_idents(~["a","b"]),
                                                rp:None,
                                                types:~[]}),
                               span:sp(0,6)})
@@ -449,7 +435,7 @@ mod test {
                                                   node:ast::expr_path(
                                                       @ast::Path{span:sp(7,8),
                                                                  global:false,
-                                                                 idents:~[intern("d")],
+                                                                 idents:~[str_to_ident("d")],
                                                                  rp:None,
                                                                  types:~[]
                                                                 }),
@@ -466,7 +452,7 @@ mod test {
                                @ast::Path{
                                    span:sp(0,1),
                                    global:false,
-                                   idents:~[intern("b")],
+                                   idents:~[str_to_ident("b")],
                                    rp:None,
                                    types: ~[]}),
                            span: sp(0,1)},
@@ -487,7 +473,7 @@ mod test {
                                                   @ast::Path{
                                                       span:sp(0,1),
                                                       global:false,
-                                                      idents:~[intern("b")],
+                                                      idents:~[str_to_ident("b")],
                                                       rp: None,
                                                       types: ~[]},
                                                   None // no idea
@@ -506,7 +492,7 @@ mod test {
                                         span:sp(4,4), // this is bizarre...
                                         // check this in the original parser?
                                         global:false,
-                                        idents:~[intern("int")],
+                                        idents:~[str_to_ident("int")],
                                         rp: None,
                                         types: ~[]},
                                                        2),
@@ -516,7 +502,7 @@ mod test {
                                                            @ast::Path{
                                                                span:sp(0,1),
                                                                global:false,
-                                                               idents:~[intern("b")],
+                                                               idents:~[str_to_ident("b")],
                                                                rp: None,
                                                                types: ~[]},
                                                            None // no idea
@@ -532,7 +518,7 @@ mod test {
         // assignment order of the node_ids.
         assert_eq!(string_to_item(@~"fn a (b : int) { b; }"),
                   Some(
-                      @ast::item{ident:intern("a"),
+                      @ast::item{ident:str_to_ident("a"),
                             attrs:~[],
                             id: 9, // fixme
                             node: ast::item_fn(ast::fn_decl{
@@ -542,7 +528,7 @@ mod test {
                                                 node: ast::ty_path(@ast::Path{
                                         span:sp(10,13),
                                         global:false,
-                                        idents:~[intern("int")],
+                                        idents:~[str_to_ident("int")],
                                         rp: None,
                                         types: ~[]},
                                                        2),
@@ -553,7 +539,7 @@ mod test {
                                                        @ast::Path{
                                                            span:sp(6,7),
                                                            global:false,
-                                                           idents:~[intern("b")],
+                                                           idents:~[str_to_ident("b")],
                                                            rp: None,
                                                            types: ~[]},
                                                        None // no idea
@@ -583,7 +569,7 @@ mod test {
                                                         @ast::Path{
                                                             span:sp(17,18),
                                                             global:false,
-                                                            idents:~[intern("b")],
+                                                            idents:~[str_to_ident("b")],
                                                             rp:None,
                                                             types: ~[]}),
                                                     span: sp(17,18)},
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 23e3f145398..2fd0a7e33ff 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -85,7 +85,7 @@ use parse::obsolete::{ObsoleteLifetimeNotation, ObsoleteConstManagedPointer};
 use parse::obsolete::{ObsoletePurity, ObsoleteStaticMethod};
 use parse::obsolete::{ObsoleteConstItem, ObsoleteFixedLengthVectorType};
 use parse::obsolete::{ObsoleteNamedExternModule, ObsoleteMultipleLocalDecl};
-use parse::token::{can_begin_expr, is_ident, is_ident_or_path};
+use parse::token::{can_begin_expr, get_ident_interner, ident_to_str, is_ident, is_ident_or_path};
 use parse::token::{is_plain_ident, INTERPOLATED, keywords, special_idents, token_to_binop};
 use parse::token;
 use parse::{new_sub_parser_from_file, next_node_id, ParseSess};
@@ -219,7 +219,7 @@ pub fn Parser(sess: @mut ParseSess,
               rdr: @reader)
            -> Parser {
     let tok0 = copy rdr.next_token();
-    let interner = rdr.interner();
+    let interner = get_ident_interner();
 
     Parser {
         reader: rdr,
@@ -333,7 +333,7 @@ impl Parser {
     pub fn get_id(&self) -> node_id { next_node_id(self.sess) }
 
     pub fn id_to_str(&self, id: ident) -> @~str {
-        self.sess.interner.get(id)
+        get_ident_interner().get(id.name)
     }
 
     // is this one of the keywords that signals a closure type?
@@ -2628,6 +2628,13 @@ impl Parser {
             // to the macro clause of parse_item_or_view_item. This
             // could use some cleanup, it appears to me.
 
+            // whoops! I now have a guess: I'm guessing the "parens-only"
+            // rule here is deliberate, to allow macro users to use parens
+            // for things that should be parsed as stmt_mac, and braces
+            // for things that should expand into items. Tricky, and
+            // somewhat awkward... and probably undocumented. Of course,
+            // I could just be wrong.
+
             check_expected_item(self, item_attrs);
 
             // Potential trouble: if we allow macros with paths instead of
@@ -3363,7 +3370,7 @@ impl Parser {
             }
             if fields.len() == 0 {
                 self.fatal(fmt!("Unit-like struct should be written as `struct %s;`",
-                                *self.interner.get(class_name)));
+                                *get_ident_interner().get(class_name.name)));
             }
             self.bump();
         } else if *self.token == token::LPAREN {
@@ -3575,7 +3582,7 @@ impl Parser {
     }
 
     fn push_mod_path(&self, id: ident, attrs: ~[ast::attribute]) {
-        let default_path = self.sess.interner.get(id);
+        let default_path = token::interner_get(id.name);
         let file_path = match ::attr::first_attr_value_str_by_name(
             attrs, "path") {
 
@@ -3598,7 +3605,7 @@ impl Parser {
         let prefix = prefix.dir_path();
         let mod_path_stack = &*self.mod_path_stack;
         let mod_path = Path(".").push_many(*mod_path_stack);
-        let default_path = *self.sess.interner.get(id) + ".rs";
+        let default_path = *token::interner_get(id.name) + ".rs";
         let file_path = match ::attr::first_attr_value_str_by_name(
             outer_attrs, "path") {
             Some(d) => {
@@ -3973,7 +3980,7 @@ impl Parser {
         match *self.token {
             token::LIT_STR(s) => {
                 self.bump();
-                let the_string = self.id_to_str(s);
+                let the_string = ident_to_str(&s);
                 let mut words = ~[];
                 for str::each_word(*the_string) |s| { words.push(s) }
                 let mut abis = AbiSet::empty();
@@ -4535,7 +4542,7 @@ impl Parser {
         match *self.token {
             token::LIT_STR(s) => {
                 self.bump();
-                self.id_to_str(s)
+                ident_to_str(&s)
             }
             _ =>  self.fatal("expected string literal")
         }
diff --git a/src/libsyntax/parse/token.rs b/src/libsyntax/parse/token.rs
index b716384c6cc..ecf83483c21 100644
--- a/src/libsyntax/parse/token.rs
+++ b/src/libsyntax/parse/token.rs
@@ -11,6 +11,7 @@
 use core::prelude::*;
 
 use ast;
+use ast::Name;
 use ast_util;
 use parse::token;
 use util::interner::StrInterner;
@@ -21,6 +22,9 @@ use core::char;
 use core::cmp::Equiv;
 use core::local_data;
 use core::str;
+use core::hashmap::HashSet;
+use core::rand;
+use core::rand::RngUtil;
 use core::to_bytes;
 
 #[deriving(Encodable, Decodable, Eq)]
@@ -176,29 +180,29 @@ pub fn to_str(in: @ident_interner, t: &Token) -> ~str {
           u.to_str() + ast_util::uint_ty_to_str(t)
       }
       LIT_INT_UNSUFFIXED(i) => { i.to_str() }
-      LIT_FLOAT(s, t) => {
-        let mut body = copy *in.get(s);
+      LIT_FLOAT(ref s, t) => {
+        let mut body = copy *ident_to_str(s);
         if body.ends_with(".") {
             body += "0";  // `10.f` is not a float literal
         }
         body + ast_util::float_ty_to_str(t)
       }
-      LIT_FLOAT_UNSUFFIXED(s) => {
-        let mut body = copy *in.get(s);
+      LIT_FLOAT_UNSUFFIXED(ref s) => {
+        let mut body = copy *ident_to_str(s);
         if body.ends_with(".") {
             body += "0";  // `10.f` is not a float literal
         }
         body
       }
-      LIT_STR(s) => { ~"\"" + str::escape_default(*in.get(s)) + "\"" }
+      LIT_STR(ref s) => { ~"\"" + str::escape_default(*ident_to_str(s)) + "\"" }
 
       /* Name components */
-      IDENT(s, _) => copy *in.get(s),
-      LIFETIME(s) => fmt!("'%s", *in.get(s)),
+      IDENT(s, _) => copy *in.get(s.name),
+      LIFETIME(s) => fmt!("'%s", *in.get(s.name)),
       UNDERSCORE => ~"_",
 
       /* Other */
-      DOC_COMMENT(s) => copy *in.get(s),
+      DOC_COMMENT(ref s) => copy *ident_to_str(s),
       EOF => ~"<eof>",
       INTERPOLATED(ref nt) => {
         match nt {
@@ -304,47 +308,47 @@ pub fn is_bar(t: &Token) -> bool {
 pub mod special_idents {
     use ast::ident;
 
-    pub static underscore : ident = ident { repr: 0, ctxt: 0};
-    pub static anon : ident = ident { repr: 1, ctxt: 0};
-    pub static invalid : ident = ident { repr: 2, ctxt: 0}; // ''
-    pub static unary : ident = ident { repr: 3, ctxt: 0};
-    pub static not_fn : ident = ident { repr: 4, ctxt: 0};
-    pub static idx_fn : ident = ident { repr: 5, ctxt: 0};
-    pub static unary_minus_fn : ident = ident { repr: 6, ctxt: 0};
-    pub static clownshoes_extensions : ident = ident { repr: 7, ctxt: 0};
+    pub static underscore : ident = ident { name: 0, ctxt: 0};
+    pub static anon : ident = ident { name: 1, ctxt: 0};
+    pub static invalid : ident = ident { name: 2, ctxt: 0}; // ''
+    pub static unary : ident = ident { name: 3, ctxt: 0};
+    pub static not_fn : ident = ident { name: 4, ctxt: 0};
+    pub static idx_fn : ident = ident { name: 5, ctxt: 0};
+    pub static unary_minus_fn : ident = ident { name: 6, ctxt: 0};
+    pub static clownshoes_extensions : ident = ident { name: 7, ctxt: 0};
 
-    pub static self_ : ident = ident { repr: 8, ctxt: 0}; // 'self'
+    pub static self_ : ident = ident { name: 8, ctxt: 0}; // 'self'
 
     /* for matcher NTs */
-    pub static item : ident = ident { repr: 9, ctxt: 0};
-    pub static block : ident = ident { repr: 10, ctxt: 0};
-    pub static stmt : ident = ident { repr: 11, ctxt: 0};
-    pub static pat : ident = ident { repr: 12, ctxt: 0};
-    pub static expr : ident = ident { repr: 13, ctxt: 0};
-    pub static ty : ident = ident { repr: 14, ctxt: 0};
-    pub static ident : ident = ident { repr: 15, ctxt: 0};
-    pub static path : ident = ident { repr: 16, ctxt: 0};
-    pub static tt : ident = ident { repr: 17, ctxt: 0};
-    pub static matchers : ident = ident { repr: 18, ctxt: 0};
+    pub static item : ident = ident { name: 9, ctxt: 0};
+    pub static block : ident = ident { name: 10, ctxt: 0};
+    pub static stmt : ident = ident { name: 11, ctxt: 0};
+    pub static pat : ident = ident { name: 12, ctxt: 0};
+    pub static expr : ident = ident { name: 13, ctxt: 0};
+    pub static ty : ident = ident { name: 14, ctxt: 0};
+    pub static ident : ident = ident { name: 15, ctxt: 0};
+    pub static path : ident = ident { name: 16, ctxt: 0};
+    pub static tt : ident = ident { name: 17, ctxt: 0};
+    pub static matchers : ident = ident { name: 18, ctxt: 0};
 
-    pub static str : ident = ident { repr: 19, ctxt: 0}; // for the type
+    pub static str : ident = ident { name: 19, ctxt: 0}; // for the type
 
     /* outside of libsyntax */
-    pub static ty_visitor : ident = ident { repr: 20, ctxt: 0};
-    pub static arg : ident = ident { repr: 21, ctxt: 0};
-    pub static descrim : ident = ident { repr: 22, ctxt: 0};
-    pub static clownshoe_abi : ident = ident { repr: 23, ctxt: 0};
-    pub static clownshoe_stack_shim : ident = ident { repr: 24, ctxt: 0};
-    pub static tydesc : ident = ident { repr: 25, ctxt: 0};
-    pub static main : ident = ident { repr: 26, ctxt: 0};
-    pub static opaque : ident = ident { repr: 27, ctxt: 0};
-    pub static blk : ident = ident { repr: 28, ctxt: 0};
-    pub static statik : ident = ident { repr: 29, ctxt: 0};
-    pub static intrinsic : ident = ident { repr: 30, ctxt: 0};
-    pub static clownshoes_foreign_mod: ident = ident { repr: 31, ctxt: 0};
-    pub static unnamed_field: ident = ident { repr: 32, ctxt: 0};
-    pub static c_abi: ident = ident { repr: 33, ctxt: 0};
-    pub static type_self: ident = ident { repr: 34, ctxt: 0};    // `Self`
+    pub static ty_visitor : ident = ident { name: 20, ctxt: 0};
+    pub static arg : ident = ident { name: 21, ctxt: 0};
+    pub static descrim : ident = ident { name: 22, ctxt: 0};
+    pub static clownshoe_abi : ident = ident { name: 23, ctxt: 0};
+    pub static clownshoe_stack_shim : ident = ident { name: 24, ctxt: 0};
+    pub static tydesc : ident = ident { name: 25, ctxt: 0};
+    pub static main : ident = ident { name: 26, ctxt: 0};
+    pub static opaque : ident = ident { name: 27, ctxt: 0};
+    pub static blk : ident = ident { name: 28, ctxt: 0};
+    pub static statik : ident = ident { name: 29, ctxt: 0};
+    pub static intrinsic : ident = ident { name: 30, ctxt: 0};
+    pub static clownshoes_foreign_mod: ident = ident { name: 31, ctxt: 0};
+    pub static unnamed_field: ident = ident { name: 32, ctxt: 0};
+    pub static c_abi: ident = ident { name: 33, ctxt: 0};
+    pub static type_self: ident = ident { name: 34, ctxt: 0};    // `Self`
 }
 
 pub struct StringRef<'self>(&'self str);
@@ -394,25 +398,22 @@ pub struct ident_interner {
 }
 
 impl ident_interner {
-    pub fn intern(&self, val: &str) -> ast::ident {
-        ast::ident { repr: self.interner.intern(val), ctxt: 0 }
+    pub fn intern(&self, val: &str) -> Name {
+        self.interner.intern(val)
     }
-    pub fn gensym(&self, val: &str) -> ast::ident {
-        ast::ident { repr: self.interner.gensym(val), ctxt: 0 }
+    pub fn gensym(&self, val: &str) -> Name {
+        self.interner.gensym(val)
     }
-    pub fn get(&self, idx: ast::ident) -> @~str {
-        self.interner.get(idx.repr)
+    pub fn get(&self, idx: Name) -> @~str {
+        self.interner.get(idx)
     }
+    // is this really something that should be exposed?
     pub fn len(&self) -> uint {
         self.interner.len()
     }
-    pub fn find_equiv<Q:Hash +
-                        IterBytes +
-                        Equiv<@~str>>(&self, val: &Q) -> Option<ast::ident> {
-        match self.interner.find_equiv(val) {
-            Some(v) => Some(ast::ident { repr: v, ctxt: 0 }),
-            None => None,
-        }
+    pub fn find_equiv<Q:Hash + IterBytes + Equiv<@~str>>(&self, val: &Q)
+                                                     -> Option<Name> {
+        self.interner.find_equiv(val)
     }
 }
 
@@ -530,11 +531,51 @@ pub fn mk_fake_ident_interner() -> @ident_interner {
 }
 
 // maps a string to its interned representation
-pub fn intern(str : &str) -> ast::ident {
+pub fn intern(str : &str) -> Name {
     let interner = get_ident_interner();
     interner.intern(str)
 }
 
+// gensyms a new uint, using the current interner
+pub fn gensym(str : &str) -> Name {
+    let interner = get_ident_interner();
+    interner.gensym(str)
+}
+
+// map an interned representation back to a string
+pub fn interner_get(name : Name) -> @~str {
+    get_ident_interner().get(name)
+}
+
+// maps an identifier to the string that it corresponds to
+pub fn ident_to_str(id : &ast::ident) -> @~str {
+    interner_get(id.name)
+}
+
+// maps a string to an identifier with an empty syntax context
+pub fn str_to_ident(str : &str) -> ast::ident {
+    ast::new_ident(intern(str))
+}
+
+// maps a string to a gensym'ed identifier
+pub fn gensym_ident(str : &str) -> ast::ident {
+    ast::new_ident(gensym(str))
+}
+
+
+// create a fresh name. In principle, this is just a
+// gensym, but for debugging purposes, you'd like the
+// resulting name to have a suggestive stringify, without
+// paying the cost of guaranteeing that the name is
+// truly unique.  I'm going to try to strike a balance
+// by using a gensym with a name that has a random number
+// at the end. So, the gensym guarantees the uniqueness,
+// and the int helps to avoid confusion.
+pub fn fresh_name(src_name : &str) -> Name {
+    let num = rand::rng().gen_uint_range(0,0xffff);
+   gensym(fmt!("%s_%u",src_name,num))
+}
+
 /**
  * All the valid words that have meaning in the Rust language.
  *
@@ -590,42 +631,42 @@ pub mod keywords {
     impl Keyword {
         pub fn to_ident(&self) -> ident {
             match *self {
-                As => ident { repr: 35, ctxt: 0 },
-                   Break => ident { repr: 36, ctxt: 0 },
-                   Const => ident { repr: 37, ctxt: 0 },
-                   Copy => ident { repr: 38, ctxt: 0 },
-                   Do => ident { repr: 39, ctxt: 0 },
-                   Else => ident { repr: 41, ctxt: 0 },
-                   Enum => ident { repr: 42, ctxt: 0 },
-                   Extern => ident { repr: 43, ctxt: 0 },
-                   False => ident { repr: 44, ctxt: 0 },
-                   Fn => ident { repr: 45, ctxt: 0 },
-                   For => ident { repr: 46, ctxt: 0 },
-                   If => ident { repr: 47, ctxt: 0 },
-                   Impl => ident { repr: 48, ctxt: 0 },
-                   Let => ident { repr: 49, ctxt: 0 },
-                   __Log => ident { repr: 50, ctxt: 0 },
-                   Loop => ident { repr: 51, ctxt: 0 },
-                   Match => ident { repr: 52, ctxt: 0 },
-                   Mod => ident { repr: 53, ctxt: 0 },
-                   Mut => ident { repr: 54, ctxt: 0 },
-                   Once => ident { repr: 55, ctxt: 0 },
-                   Priv => ident { repr: 56, ctxt: 0 },
-                   Pub => ident { repr: 57, ctxt: 0 },
-                   Pure => ident { repr: 58, ctxt: 0 },
-                   Ref => ident { repr: 59, ctxt: 0 },
-                   Return => ident { repr: 60, ctxt: 0 },
-                   Static => ident { repr: 29, ctxt: 0 },
-                   Self => ident { repr: 8, ctxt: 0 },
-                   Struct => ident { repr: 61, ctxt: 0 },
-                   Super => ident { repr: 62, ctxt: 0 },
-                   True => ident { repr: 63, ctxt: 0 },
-                   Trait => ident { repr: 64, ctxt: 0 },
-                   Type => ident { repr: 65, ctxt: 0 },
-                   Unsafe => ident { repr: 66, ctxt: 0 },
-                   Use => ident { repr: 67, ctxt: 0 },
-                   While => ident { repr: 68, ctxt: 0 },
-                   Be => ident { repr: 69, ctxt: 0 },
+                As => ident { name: 35, ctxt: 0 },
+                   Break => ident { name: 36, ctxt: 0 },
+                   Const => ident { name: 37, ctxt: 0 },
+                   Copy => ident { name: 38, ctxt: 0 },
+                   Do => ident { name: 39, ctxt: 0 },
+                   Else => ident { name: 41, ctxt: 0 },
+                   Enum => ident { name: 42, ctxt: 0 },
+                   Extern => ident { name: 43, ctxt: 0 },
+                   False => ident { name: 44, ctxt: 0 },
+                   Fn => ident { name: 45, ctxt: 0 },
+                   For => ident { name: 46, ctxt: 0 },
+                   If => ident { name: 47, ctxt: 0 },
+                   Impl => ident { name: 48, ctxt: 0 },
+                   Let => ident { name: 49, ctxt: 0 },
+                   __Log => ident { name: 50, ctxt: 0 },
+                   Loop => ident { name: 51, ctxt: 0 },
+                   Match => ident { name: 52, ctxt: 0 },
+                   Mod => ident { name: 53, ctxt: 0 },
+                   Mut => ident { name: 54, ctxt: 0 },
+                   Once => ident { name: 55, ctxt: 0 },
+                   Priv => ident { name: 56, ctxt: 0 },
+                   Pub => ident { name: 57, ctxt: 0 },
+                   Pure => ident { name: 58, ctxt: 0 },
+                   Ref => ident { name: 59, ctxt: 0 },
+                   Return => ident { name: 60, ctxt: 0 },
+                   Static => ident { name: 29, ctxt: 0 },
+                   Self => ident { name: 8, ctxt: 0 },
+                   Struct => ident { name: 61, ctxt: 0 },
+                   Super => ident { name: 62, ctxt: 0 },
+                   True => ident { name: 63, ctxt: 0 },
+                   Trait => ident { name: 64, ctxt: 0 },
+                   Type => ident { name: 65, ctxt: 0 },
+                   Unsafe => ident { name: 66, ctxt: 0 },
+                   Use => ident { name: 67, ctxt: 0 },
+                   While => ident { name: 68, ctxt: 0 },
+                   Be => ident { name: 69, ctxt: 0 },
             }
         }
     }
@@ -633,14 +674,14 @@ pub mod keywords {
 
 pub fn is_keyword(kw: keywords::Keyword, tok: &Token) -> bool {
     match *tok {
-        token::IDENT(sid, false) => { kw.to_ident().repr == sid.repr }
+        token::IDENT(sid, false) => { kw.to_ident().name == sid.name }
         _ => { false }
     }
 }
 
 pub fn is_any_keyword(tok: &Token) -> bool {
     match *tok {
-        token::IDENT(sid, false) => match sid.repr {
+        token::IDENT(sid, false) => match sid.name {
             8 | 29 | 35 .. 69 => true,
             _ => false,
         },
@@ -650,7 +691,7 @@ pub fn is_any_keyword(tok: &Token) -> bool {
 
 pub fn is_strict_keyword(tok: &Token) -> bool {
     match *tok {
-        token::IDENT(sid, false) => match sid.repr {
+        token::IDENT(sid, false) => match sid.name {
             8 | 29 | 35 .. 68 => true,
             _ => false,
         },
@@ -660,10 +701,21 @@ pub fn is_strict_keyword(tok: &Token) -> bool {
 
 pub fn is_reserved_keyword(tok: &Token) -> bool {
     match *tok {
-        token::IDENT(sid, false) => match sid.repr {
+        token::IDENT(sid, false) => match sid.name {
             69 => true,
             _ => false,
         },
         _ => false,
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use std::io;
+    #[test] fn t1() {
+        let a = fresh_name("ghi");
+        io::println(fmt!("interned name: %u,\ntextual name: %s\n",
+                         a,*interner_get(a)));
+    }
+}
diff --git a/src/libsyntax/print/pprust.rs b/src/libsyntax/print/pprust.rs
index 7a3eddbd573..57e78d3ad84 100644
--- a/src/libsyntax/print/pprust.rs
+++ b/src/libsyntax/print/pprust.rs
@@ -21,7 +21,7 @@ use codemap::{CodeMap, BytePos};
 use codemap;
 use diagnostic;
 use parse::classify::expr_is_simple_block;
-use parse::token::ident_interner;
+use parse::token::{ident_interner, ident_to_str};
 use parse::{comments, token};
 use parse;
 use print::pp::{break_offset, word, space, zerobreak, hardbreak};
@@ -1475,7 +1475,7 @@ pub fn print_decl(s: @ps, decl: @ast::decl) {
 }
 
 pub fn print_ident(s: @ps, ident: ast::ident) {
-    word(s.s, *s.intr.get(ident));
+    word(s.s, *ident_to_str(&ident));
 }
 
 pub fn print_for_decl(s: @ps, loc: @ast::local, coll: @ast::expr) {
@@ -2236,7 +2236,7 @@ mod test {
     use codemap;
     use core::cmp::Eq;
     use core::option::None;
-    use parse;
+    use parse::token;
 
     fn string_check<T:Eq> (given : &T, expected: &T) {
         if !(given == expected) {
@@ -2246,8 +2246,7 @@ mod test {
 
     #[test]
     fn test_fun_to_str() {
-        let mock_interner = parse::token::mk_fake_ident_interner();
-        let abba_ident = mock_interner.intern("abba");
+        let abba_ident = token::str_to_ident("abba");
 
         let decl = ast::fn_decl {
             inputs: ~[],
@@ -2258,14 +2257,13 @@ mod test {
         };
         let generics = ast_util::empty_generics();
         assert_eq!(&fun_to_str(&decl, ast::impure_fn, abba_ident,
-                               None, &generics, mock_interner),
+                               None, &generics, token::get_ident_interner()),
                    &~"fn abba()");
     }
 
     #[test]
     fn test_variant_to_str() {
-        let mock_interner = parse::token::mk_fake_ident_interner();
-        let ident = mock_interner.intern("principal_skinner");
+        let ident = token::str_to_ident("principal_skinner");
 
         let var = codemap::respan(codemap::dummy_sp(), ast::variant_ {
             name: ident,
@@ -2277,7 +2275,7 @@ mod test {
             vis: ast::public,
         });
 
-        let varstr = variant_to_str(&var,mock_interner);
+        let varstr = variant_to_str(&var,token::get_ident_interner());
         assert_eq!(&varstr,&~"pub principal_skinner");
     }
 }
diff --git a/src/libsyntax/util/interner.rs b/src/libsyntax/util/interner.rs
index c3deb65163d..b55050184fe 100644
--- a/src/libsyntax/util/interner.rs
+++ b/src/libsyntax/util/interner.rs
@@ -64,9 +64,6 @@ impl<T:Eq + IterBytes + Hash + Const + Copy> Interner<T> {
         new_idx
     }
 
-    // this isn't "pure" in the traditional sense, because it can go from
-    // failing to returning a value as items are interned. But for typestate,
-    // where we first check a pred and then rely on it, ceasing to fail is ok.
     pub fn get(&self, idx: uint) -> T { self.vect[idx] }
 
     pub fn len(&self) -> uint { let vect = &*self.vect; vect.len() }
diff --git a/src/libsyntax/util/parser_testing.rs b/src/libsyntax/util/parser_testing.rs
index 1c2210c96b6..c5528069926 100644
--- a/src/libsyntax/util/parser_testing.rs
+++ b/src/libsyntax/util/parser_testing.rs
@@ -10,11 +10,11 @@
 
 use core::option::{Option,None};
 use ast;
-use parse::parser::Parser;
 use parse::{new_parse_sess};
-
-use syntax::parse::{ParseSess,string_to_filemap,filemap_to_tts};
-use syntax::parse::{new_parser_from_source_str};
+use parse::{ParseSess,string_to_filemap,filemap_to_tts};
+use parse::{new_parser_from_source_str};
+use parse::parser::Parser;
+use parse::token;
 
 // map a string to tts, using a made-up filename: return both the token_trees
 // and the ParseSess
@@ -54,7 +54,18 @@ pub fn string_to_item_and_sess (source_str : @~str) -> (Option<@ast::item>,@mut
     (p.parse_item(~[]),ps)
 }
 
-pub fn string_to_stmt (source_str : @~str) -> @ast::stmt {
+// parse a string, return a stmt
+pub fn string_to_stmt(source_str : @~str) -> @ast::stmt {
     string_to_parser(source_str).parse_stmt(~[])
 }
 
+// parse a string, return a pat. Uses "irrefutable"... which doesn't
+// (currently) affect parsing.
+pub fn string_to_pat(source_str : @~str) -> @ast::pat {
+    string_to_parser(source_str).parse_pat()
+}
+
+// convert a vector of strings to a vector of ast::idents
+pub fn strs_to_idents(ids: ~[&str]) -> ~[ast::ident] {
+    ids.map(|u| token::str_to_ident(*u))
+}