Parse, add to AST, and otherwise ignore 'export' view items. Need to add support to resolve.

Author: graydon

src/comp/front/ast.rs

@@ -279,6 +279,7 @@ type view_item = spanned[view_item_];
 tag view_item_ {
     view_item_use(ident, vec[@meta_item], def_id);
     view_item_import(ident, vec[ident], def_id, option.t[def]);
+    view_item_export(ident);
 }
 
 type item = spanned[item_];
@@ -306,6 +307,11 @@ fn index_view_item(mod_index index, @view_item it) {
         case(ast.view_item_import(?def_ident,_,_,_)) {
             index.insert(def_ident, ast.mie_view_item(it));
         }
+        case(ast.view_item_export(_)) {
+            // NB: don't index these, they might collide with
+            // the import or use that they're exporting. Have
+            // to do linear search for exports.
+        }
     }
 }
 

src/comp/front/parser.rs

@@ -2187,31 +2187,43 @@ impure fn parse_import(parser p) -> @ast.view_item {
     fail;
 }
 
-impure fn parse_use_or_import(parser p) -> @ast.view_item {
+impure fn parse_export(parser p) -> @ast.view_item {
+    auto lo = p.get_span();
+    expect(p, token.EXPORT);
+    auto id = parse_ident(p);
+    auto hi = p.get_span();
+    expect(p, token.SEMI);
+    ret @spanned(lo, hi, ast.view_item_export(id));
+}
+
+impure fn parse_view_item(parser p) -> @ast.view_item {
     alt (p.peek()) {
         case (token.USE) {
             ret parse_use(p);
         }
         case (token.IMPORT) {
             ret parse_import(p);
         }
+        case (token.EXPORT) {
+            ret parse_export(p);
+        }
     }
 }
 
-fn is_use_or_import(token.token t) -> bool {
-    if (t == token.USE) {
-        ret true;
-    }
-    if (t == token.IMPORT) {
-        ret true;
+fn is_view_item(token.token t) -> bool {
+    alt (t) {
+        case (token.USE) { ret true; }
+        case (token.IMPORT) { ret true; }
+        case (token.EXPORT) { ret true; }
+        case (_) {}
     }
     ret false;
 }
 
 impure fn parse_view(parser p, ast.mod_index index) -> vec[@ast.view_item] {
     let vec[@ast.view_item] items = vec();
-    while (is_use_or_import(p.peek())) {
-        auto item = parse_use_or_import(p);
+    while (is_view_item(p.peek())) {
+        auto item = parse_view_item(p);
         items += vec(item);
 
         ast.index_view_item(index, item);
@@ -2305,12 +2317,17 @@ impure fn parse_crate_directive(parser p) -> ast.crate_directive
         }
 
         case (token.USE) {
-            auto vi = parse_use_or_import(p);
+            auto vi = parse_view_item(p);
             ret spanned(lo, vi.span, ast.cdir_view_item(vi));
         }
 
         case (token.IMPORT) {
-            auto vi = parse_use_or_import(p);
+            auto vi = parse_view_item(p);
+            ret spanned(lo, vi.span, ast.cdir_view_item(vi));
+        }
+
+        case (token.EXPORT) {
+            auto vi = parse_view_item(p);
             ret spanned(lo, vi.span, ast.cdir_view_item(vi));
         }