The few and proud isolated bits from stdlib-work so far that don't break everything. Note util.rs hasn't yet been declared mod in the std crate. Don't do that yet, as it breaks make check.

1 files changed, 46 insertions, 0 deletions

diff --git a/src/lib/util.rs b/src/lib/util.rs
new file mode 100644
index 00000000..bf57bb52
--- /dev/null
+++ b/src/lib/util.rs
@@ -0,0 +1,46 @@
+type option[T] = tag(none(), some(T));
+type box[T] = tup(@T);
+type boxo[T] = option[box[T]];
+type boxm[T] = tup(mutable @T);
+type boxmo[T] = option[boxm[T]];
+
+type map[T, U] = fn(&T) -> U;
+
+fn option_map[T, U](map[T, U] f, &option[T] opt) -> option[U] {
+  alt (opt) {
+    case (some[T](x)) {
+      ret some[U](f[T, U](x));
+    }
+    case (none[T]()) {
+      ret none[U]();
+    }
+  }
+}
+
+fn unbox[T](&box[T] b) -> T {
+  ret b._0;
+}
+
+
+fn unboxm[T](&boxm[T] b) -> T {
+  ret b._0;
+}
+
+fn unboxo[T](boxo[T] b) -> option[T] {
+  // Pending issue #90, no need to alias the function item in order to pass
+  // it as an arg.
+  let map[box[T], T] f = unbox[T];
+  be option_map[box[T], T](f, b);
+}
+
+fn unboxmo[T](boxmo[T] b) -> option[T] {
+  // Issue #90, as above
+  let map[boxm[T], T] f = unboxm[T];
+  be option_map[boxm[T], T](f, b);
+}
+
+fn id[T](T x) -> T {
+  ret x;
+}
+
+type rational = rec(int num, int den);