Redo yesterday's buf_writer-wrapper in a less silly and convoluted wa…

…y. Add integer stringifying functions to _int module.

src/lib/_int.rs

@@ -44,3 +44,47 @@ fn next_power_of_two(uint n) -> uint {
   }
   ret tmp + 1u;
 }
+
+fn uto_string(mutable uint n, uint radix) -> str
+{
+  check (0u < radix && radix <= 16u);
+  fn digit(uint n) -> str {
+    alt (n) {
+      case (0u) { ret "0"; }
+      case (1u) { ret "1"; }
+      case (2u) { ret "2"; }
+      case (3u) { ret "3"; }
+      case (4u) { ret "4"; }
+      case (5u) { ret "5"; }
+      case (6u) { ret "6"; }
+      case (7u) { ret "7"; }
+      case (8u) { ret "8"; }
+      case (9u) { ret "9"; }
+      case (10u) { ret "A"; }
+      case (11u) { ret "B"; }
+      case (12u) { ret "C"; }
+      case (13u) { ret "D"; }
+      case (14u) { ret "E"; }
+      case (15u) { ret "F"; }
+    }
+  }
+
+  if (n == 0u) { ret "0"; }
+
+  let str s = "";
+  while (n > 0u) {
+    s = digit(n % radix) + s;
+    n /= radix;
+  }
+  ret s;
+}
+
+fn to_string(mutable int n, uint radix) -> str
+{
+  check (0u < radix && radix <= 16u);
+  if (n < 0) {
+    ret "-" + uto_string((-n) as uint, radix);
+  } else {
+    ret uto_string(n as uint, radix);
+  }
+}

src/lib/_io.rs

@@ -112,49 +112,21 @@ fn new_buf_writer(str path, vec[fileflag] flags) -> buf_writer {
   ret fd_buf_writer(fd);
 }
 
-type formatter[T] = fn(&T x) -> vec[u8];
-
-type writer[T] = unsafe obj { fn write(&T x); };
-
-fn mk_writer[T](str path,
-                vec[fileflag] flags,
-                &formatter[T] fmt)
-  -> writer[T]
-{
-  unsafe obj w[T](buf_writer out, formatter[T] fmt) {
-    fn write(&T x) {
-      out.write(fmt(x));
-    }
-  }
-  ret w[T](new_buf_writer(path, flags), fmt);
-}
-
-/* TODO: int_writer, uint_writer, ... */
-
-fn str_writer(str path, vec[fileflag] flags) -> writer[str] {
-  auto fmt = _str.bytes; // FIXME (issue #90)
-  ret mk_writer[str](path, flags, fmt);
-}
-
-fn vec_writer[T](str path,
-                 vec[fileflag] flags,
-                 &formatter[T] inner)
-  -> writer[vec[T]]
+type writer =
+  unsafe obj {
+    fn write_str(str s);
+    fn write_int(int n);
+    fn write_uint(uint n);
+  };
+
+fn file_writer(str path,
+               vec[fileflag] flags)
+  -> writer
 {
-  fn fmt[T](&vec[T] v, &formatter[T] inner) -> vec[u8] {
-    let vec[u8] res = _str.bytes("vec(");
-    auto first = true;
-    for (T x in v) {
-      if (!first) {
-        res += _str.bytes(", ");
-      } else {
-        first = false;
-      }
-      res += inner(x);
-    }
-    res += _str.bytes(")\n");
-    ret res;
+  unsafe obj fw(buf_writer out) {
+    fn write_str(str s)   { out.write(_str.bytes(s)); }
+    fn write_int(int n)   { out.write(_str.bytes(_int.to_string(n, 10u))); }
+    fn write_uint(uint n) { out.write(_str.bytes(_int.uto_string(n, 10u))); }
   }
-
-  ret mk_writer[vec[T]](path, flags, bind fmt[T](_, inner));
+  ret fw(new_buf_writer(path, flags));
 }