Export all enum variants by default; new syntax for selectively exporting variants

See issue 1426 for details. Now, the semantics of "export t;" where t is a tag are
to export all of t's variants as well. "export t{};" exports t but not its
variants, while "export t{a, b, c};" exports only variants a, b, c of t.

To do:
- documentation
- there's currently no checking that a, b, c are actually variants of t in the
 above example
- there's also no checking that t is an enum type, in the second two examples above
- change the modules listed in issue 1426 that should have the old export
semantics to use the t{} syntax

I deleted the test export-no-tag-variants since we're doing the opposite now,
and other tests cover the same behavior.

1 files changed, 13 insertions, 0 deletions

diff --git a/src/comp/syntax/print/pprust.rs b/src/comp/syntax/print/pprust.rs
index a57cf3add14..2ebcaa055a7 100644
--- a/src/comp/syntax/print/pprust.rs
+++ b/src/comp/syntax/print/pprust.rs
@@ -1303,6 +1303,19 @@ fn print_view_item(s: ps, item: @ast::view_item) {
         commasep(s, inconsistent, ids,
                  fn@(s: ps, &&w: ast::ident) { word(s.s, w) });
       }
+      ast::view_item_export_tag_none(id, _) {
+          head(s, "export");
+          word(s.s, id);
+          word(s.s, "::{}");
+      }
+      ast::view_item_export_tag_some(id, ids, _) {
+          head(s, "export");
+          word(s.s, id);
+          word(s.s, "::{");
+          commasep(s, inconsistent, ids, fn@(s:ps, &&w: ast::import_ident) {
+                  word(s.s, w.node.name) });
+          word(s.s, "}");
+      }
     }
     word(s.s, ";");
     end(s); // end inner head-block