Test the buffered reader and writer in _io.

src/lib/_io.rs

@@ -84,7 +84,18 @@ fn new_buf_reader(str path) -> buf_reader {
     ret fd_buf_reader(fd, new_buf());
 }
 
-type fileflag = tag(append(), create(), truncate());
+/**
+ * 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; }
 
 fn new_buf_writer(str path, vec[fileflag] flags) -> buf_writer {
 
@@ -117,9 +128,13 @@ fn new_buf_writer(str path, vec[fileflag] flags) -> buf_writer {
 
     for (fileflag f in flags) {
         alt (f) {
-            case (append())   { fflags |= os.libc_constants.O_APPEND(); }
+            // FIXME (issue #150): cf comment above defn of fileflag type
-            case (create())   { fflags |= os.libc_constants.O_CREAT(); }
+            //case (append())   { fflags |= os.libc_constants.O_APPEND(); }
-            case (truncate()) { fflags |= os.libc_constants.O_TRUNC(); }
+            //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(); }
         }
     }
 

src/lib/_str.rs

@@ -11,6 +11,22 @@ native "rust" mod rustrt {
   fn refcount[T](str s) -> uint;
 }
 
+fn eq(str a, str b) -> bool {
+  let uint i = byte_len(a);
+  if (byte_len(b) != i) {
+    ret false;
+  }
+  while (i > 0u) {
+    i -= 1u;
+    auto cha = a.(i);
+    auto chb = b.(i);
+    if (cha != chb) {
+      ret false;
+    }
+  }
+  ret true;
+}
+
 fn is_utf8(vec[u8] v) -> bool {
   fail; // FIXME
 }

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

@@ -0,0 +1,26 @@
+// -*- rust -*-
+
+use std;
+import std._io;
+import std._str;
+
+fn test_simple(str tmpfilebase) {
+  let str tmpfile = tmpfilebase + ".tmp";
+  log tmpfile;
+  let str frood = "A hoopy frood who really knows where his towel is.";
+  log frood;
+
+  {
+    let _io.buf_writer out = _io.new_buf_writer(tmpfile, vec(_io.create()));
+    out.write(_str.bytes(frood));
+  }
+
+  let _io.buf_reader inp = _io.new_buf_reader(tmpfile);
+  let str frood2 = _str.from_bytes(inp.read());
+  log frood2;
+  check (_str.eq(frood, frood2));
+}
+
+fn main(vec[str] argv) {
+  test_simple(argv.(0));
+}