Change io.fileflag to a tag type. Remove FIXME

Author: brson

src/lib/io.rs

@@ -85,18 +85,11 @@ fn new_buf_reader(str path) -> buf_reader {
     ret fd_buf_reader(fd, new_buf());
 }
 
-/**
- * FIXME (issue #150):  This should be
- *
- *   type fileflag = tag(append(), create(), truncate());
- *
- * but then the tag value ctors are not found from crate-importers of std, so
- * we manually simulate the enum below.
- */
-type fileflag = uint;
-fn append() -> uint { ret 0u; }
-fn create() -> uint { ret 1u; }
-fn truncate() -> uint { ret 2u; }
+tag fileflag {
+    append;
+    create;
+    truncate;
+}
 
 fn new_buf_writer(str path, vec[fileflag] flags) -> buf_writer {
 
@@ -129,13 +122,9 @@ fn new_buf_writer(str path, vec[fileflag] flags) -> buf_writer {
 
     for (fileflag f in flags) {
         alt (f) {
-            // FIXME (issue #150): cf comment above defn of fileflag type
-            //case (append())   { fflags |= os.libc_constants.O_APPEND(); }
-            //case (create())   { fflags |= os.libc_constants.O_CREAT(); }
-            //case (truncate()) { fflags |= os.libc_constants.O_TRUNC(); }
-            case (0u)   { fflags |= os.libc_constants.O_APPEND(); }
-            case (1u)   { fflags |= os.libc_constants.O_CREAT(); }
-            case (2u) { fflags |= os.libc_constants.O_TRUNC(); }
+            case (append)   { fflags |= os.libc_constants.O_APPEND(); }
+            case (create)   { fflags |= os.libc_constants.O_CREAT(); }
+            case (truncate) { fflags |= os.libc_constants.O_TRUNC(); }
         }
     }
 

src/test/run-pass/lib-io.rs

@@ -11,7 +11,7 @@ fn test_simple(str tmpfilebase) {
   log frood;
 
   {
-    let io.buf_writer out = io.new_buf_writer(tmpfile, vec(io.create()));
+    let io.buf_writer out = io.new_buf_writer(tmpfile, vec(io.create));
     out.write(_str.bytes(frood));
   }