Have parser recognize static, self region.

Fixes a bug in methods that &self couldn't be referenced in the
body. Also fixes #2479.

Author: nikomatsakis

src/libsyntax/ast.rs

@@ -1047,7 +1047,12 @@ impl prim_ty : cmp::Eq {
 type region = {id: node_id, node: region_};
 
 #[auto_serialize]
-enum region_ { re_anon, re_named(ident) }
+enum region_ {
+    re_anon,
+    re_static,
+    re_self,
+    re_named(ident)
+}
 
 #[auto_serialize]
 enum ty_ {

src/libsyntax/parse/parser.rs

@@ -4,7 +4,7 @@ use result::Result;
 use either::{Either, Left, Right};
 use std::map::{HashMap, str_hash};
 use token::{can_begin_expr, is_ident, is_ident_or_path, is_plain_ident,
-               INTERPOLATED};
+            INTERPOLATED, special_idents};
 use codemap::{span,fss_none};
 use util::interner::interner;
 use ast_util::{spanned, respan, mk_sp, ident_to_path, operator_prec};
@@ -51,7 +51,8 @@ use ast::{_mod, add, alt_check, alt_exhaustive, arg, arm, attribute,
              pat_ident, pat_lit, pat_range, pat_rec, pat_region, pat_struct,
              pat_tup, pat_uniq, pat_wild, path, private, proto, proto_bare,
              proto_block, proto_box, proto_uniq, provided, public, pure_fn,
-             purity, re_anon, re_named, region, rem, required, ret_style,
+             purity, re_static, re_self, re_anon, re_named, region,
+             rem, required, ret_style,
              return_val, self_ty, shl, shr, stmt, stmt_decl, stmt_expr,
              stmt_semi, struct_def, struct_field, struct_variant_kind,
              subtract, sty_box, sty_by_ref, sty_region, sty_static, sty_uniq,
@@ -432,8 +433,10 @@ impl parser {
 
     fn region_from_name(s: Option<ident>) -> @region {
         let r = match s {
-          Some (id) => re_named(id),
-          None => re_anon
+            Some(id) if id == special_idents::static => ast::re_static,
+            Some(id) if id == special_idents::self_ => re_self,
+            Some(id) => re_named(id),
+            None => re_anon
         };
 
         @{id: self.get_id(), node: r}
@@ -614,7 +617,7 @@ impl parser {
                 let name = self.parse_value_ident();
                 self.bump();
                 name
-            } else { token::special_idents::invalid }
+            } else { special_idents::invalid }
         };
 
         let t = self.parse_ty(false);
@@ -2388,7 +2391,7 @@ impl parser {
 
     fn is_self_ident() -> bool {
         match self.token {
-          token::IDENT(id, false) if id == token::special_idents::self_
+          token::IDENT(id, false) if id == special_idents::self_
             => true,
           _ => false
         }
@@ -2603,7 +2606,7 @@ impl parser {
 
         // This is a new-style impl declaration.
         // XXX: clownshoes
-        let ident = token::special_idents::clownshoes_extensions;
+        let ident = special_idents::clownshoes_extensions;
 
         // Parse the type.
         let ty = self.parse_ty(false);
@@ -3019,7 +3022,7 @@ impl parser {
                 }
 
                 (ast::anonymous,
-                 token::special_idents::clownshoes_foreign_mod)
+                 special_idents::clownshoes_foreign_mod)
             }
         };
 

src/libsyntax/print/pprust.rs

@@ -328,14 +328,24 @@ fn print_foreign_mod(s: ps, nmod: ast::foreign_mod,
     for nmod.items.each |item| { print_foreign_item(s, item); }
 }
 
-fn print_region(s: ps, region: @ast::region) {
+fn print_region(s: ps, region: @ast::region, sep: ~str) {
     match region.node {
-      ast::re_anon => word_space(s, ~"&"),
-      ast::re_named(name) => {
-        word(s.s, ~"&");
-        print_ident(s, name);
-      }
+        ast::re_anon => {
+            word_space(s, ~"&");
+            return;
+        }
+        ast::re_static => {
+            word_space(s, ~"&static")
+        }
+        ast::re_self => {
+            word_space(s, ~"&self")
+        }
+        ast::re_named(name) => {
+            word(s.s, ~"&");
+            print_ident(s, name);
+        }
     }
+    word(s.s, sep);
 }
 
 fn print_type(s: ps, &&ty: @ast::ty) {
@@ -362,11 +372,8 @@ fn print_type_ex(s: ps, &&ty: @ast::ty, print_colons: bool) {
       }
       ast::ty_ptr(mt) => { word(s.s, ~"*"); print_mt(s, mt); }
       ast::ty_rptr(region, mt) => {
-        match region.node {
-          ast::re_anon => word(s.s, ~"&"),
-          _ => { print_region(s, region); word(s.s, ~"/"); }
-        }
-        print_mt(s, mt);
+          print_region(s, region, ~"/");
+          print_mt(s, mt);
       }
       ast::ty_rec(fields) => {
         word(s.s, ~"{");
@@ -961,18 +968,11 @@ fn print_mac(s: ps, m: ast::mac) {
 
 fn print_vstore(s: ps, t: ast::vstore) {
     match t {
-      ast::vstore_fixed(Some(i)) => word(s.s, fmt!("%u", i)),
-      ast::vstore_fixed(None) => word(s.s, ~"_"),
-      ast::vstore_uniq => word(s.s, ~"~"),
-      ast::vstore_box => word(s.s, ~"@"),
-      ast::vstore_slice(r) => match r.node {
-        ast::re_anon => word(s.s, ~"&"),
-        ast::re_named(name) => {
-            word(s.s, ~"&");
-            print_ident(s, name);
-            word(s.s, ~".");
-        }
-      }
+        ast::vstore_fixed(Some(i)) => word(s.s, fmt!("%u", i)),
+        ast::vstore_fixed(None) => word(s.s, ~"_"),
+        ast::vstore_uniq => word(s.s, ~"~"),
+        ast::vstore_box => word(s.s, ~"@"),
+        ast::vstore_slice(r) => print_region(s, r, ~"/")
     }
 }
 
@@ -1455,7 +1455,7 @@ fn print_path(s: ps, &&path: @ast::path, colons_before_params: bool) {
           None => { /* ok */ }
           Some(r) => {
             word(s.s, ~"/");
-            print_region(s, r);
+            print_region(s, r, ~"");
           }
         }
 

src/rustc/middle/region.rs

@@ -522,10 +522,10 @@ impl determine_rp_ctxt {
     // that flag to false when we enter a method.
     fn region_is_relevant(r: @ast::region) -> bool {
         match r.node {
+            ast::re_static => false,
             ast::re_anon => self.anon_implies_rp,
-            ast::re_named(id) => {
-                id == syntax::parse::token::special_idents::self_
-            }
+            ast::re_self => true,
+            ast::re_named(_) => false
         }
     }
 

src/rustc/middle/typeck/astconv.rs

@@ -73,8 +73,10 @@ fn ast_region_to_region<AC: ast_conv, RS: region_scope Copy Owned>(
     self: AC, rscope: RS, span: span, a_r: @ast::region) -> ty::region {
 
     let res = match a_r.node {
-      ast::re_anon => rscope.anon_region(span),
-      ast::re_named(id) => rscope.named_region(span, id)
+        ast::re_static => Ok(ty::re_static),
+        ast::re_anon => rscope.anon_region(span),
+        ast::re_self => rscope.self_region(span),
+        ast::re_named(id) => rscope.named_region(span, id)
     };
 
     get_region_reporting_err(self.tcx(), span, res)

src/rustc/middle/typeck/check.rs

@@ -77,6 +77,7 @@ use syntax::ast::ty_i;
 use typeck::infer::{resolve_type, force_tvar};
 use result::{Result, Ok, Err};
 use syntax::print::pprust;
+use syntax::parse::token::special_idents;
 
 use std::map::{str_hash, uint_hash};
 
@@ -567,22 +568,34 @@ impl @fn_ctxt: ast_conv {
     }
 }
 
+impl @fn_ctxt {
+    fn search_in_scope_regions(br: ty::bound_region)
+        -> Result<ty::region, ~str>
+    {
+        match self.in_scope_regions.find(br) {
+            Some(r) => result::Ok(r),
+            None => {
+                let blk_br = ty::br_named(special_idents::blk);
+                if br == blk_br {
+                    result::Ok(self.block_region())
+                } else {
+                    result::Err(fmt!("named region `%s` not in scope here",
+                                     bound_region_to_str(self.tcx(), br)))
+                }
+            }
+        }
+    }
+}
+
 impl @fn_ctxt: region_scope {
     fn anon_region(span: span) -> Result<ty::region, ~str> {
         result::Ok(self.infcx().next_region_var_nb(span))
     }
-    fn named_region(span: span, id: ast::ident) -> Result<ty::region, ~str> {
-        do empty_rscope.named_region(span, id).chain_err |_e| {
-            match self.in_scope_regions.find(ty::br_named(id)) {
-              Some(r) => result::Ok(r),
-              None if id == syntax::parse::token::special_idents::blk
-                  => result::Ok(self.block_region()),
-              None => {
-                result::Err(fmt!("named region `%s` not in scope here",
-                                 self.ccx.tcx.sess.str_of(id)))
-              }
-            }
-        }
+    fn self_region(_span: span) -> Result<ty::region, ~str> {
+        self.search_in_scope_regions(ty::br_self)
+    }
+    fn named_region(_span: span, id: ast::ident) -> Result<ty::region, ~str> {
+        self.search_in_scope_regions(ty::br_named(id))
     }
 }
 

src/rustc/middle/typeck/rscope.rs

@@ -3,6 +3,7 @@ use syntax::parse::token::special_idents;
 
 trait region_scope {
     fn anon_region(span: span) -> Result<ty::region, ~str>;
+    fn self_region(span: span) -> Result<ty::region, ~str>;
     fn named_region(span: span, id: ast::ident) -> Result<ty::region, ~str>;
 }
 
@@ -11,9 +12,13 @@ impl empty_rscope: region_scope {
     fn anon_region(_span: span) -> Result<ty::region, ~str> {
         result::Ok(ty::re_static)
     }
-    fn named_region(_span: span, id: ast::ident) -> Result<ty::region, ~str> {
-        if id == special_idents::static { result::Ok(ty::re_static) }
-        else { result::Err(~"only the static region is allowed here") }
+    fn self_region(_span: span) -> Result<ty::region, ~str> {
+        result::Err(~"only the static region is allowed here")
+    }
+    fn named_region(_span: span, _id: ast::ident)
+        -> Result<ty::region, ~str>
+    {
+        result::Err(~"only the static region is allowed here")
     }
 }
 
@@ -26,14 +31,13 @@ impl type_rscope: region_scope {
                                 type must be declared with a region bound")
         }
     }
+    fn self_region(span: span) -> Result<ty::region, ~str> {
+        self.anon_region(span)
+    }
     fn named_region(span: span, id: ast::ident) -> Result<ty::region, ~str> {
         do empty_rscope.named_region(span, id).chain_err |_e| {
-            if id == special_idents::self_ {
-                self.anon_region(span)
-            } else {
-                result::Err(~"named regions other than `self` are not \
-                             allowed as part of a type declaration")
-            }
+            result::Err(~"named regions other than `self` are not \
+                          allowed as part of a type declaration")
         }
     }
 }
@@ -54,6 +58,9 @@ impl @anon_rscope: region_scope {
     fn anon_region(_span: span) -> Result<ty::region, ~str> {
         result::Ok(self.anon)
     }
+    fn self_region(span: span) -> Result<ty::region, ~str> {
+        self.base.self_region(span)
+    }
     fn named_region(span: span, id: ast::ident) -> Result<ty::region, ~str> {
         self.base.named_region(span, id)
     }
@@ -74,6 +81,9 @@ impl @binding_rscope: region_scope {
         self.anon_bindings += 1;
         result::Ok(ty::re_bound(ty::br_anon(idx)))
     }
+    fn self_region(span: span) -> Result<ty::region, ~str> {
+        self.base.self_region(span)
+    }
     fn named_region(span: span, id: ast::ident) -> Result<ty::region, ~str> {
         do self.base.named_region(span, id).chain_err |_e| {
             result::Ok(ty::re_bound(ty::br_named(id)))