add meta data support to atoms

Author: mpenet

pixie/vm/atom.py

@@ -10,8 +10,15 @@ class Atom(object.Object):
     def type(self):
         return Atom._type
 
-    def __init__(self, boxed_value):
+    def with_meta(self, meta):
+        return Atom(self._boxed_value, meta)
+
+    def meta(self):
+        return self._meta
+
+    def __init__(self, boxed_value, meta=nil):
         self._boxed_value = boxed_value
+        self._meta = meta
 
 
 @extend(proto._reset_BANG_, Atom)
@@ -26,6 +33,15 @@ def _deref(self):
     assert isinstance(self, Atom)
     return self._boxed_value
 
+@extend(proto._meta, Atom)
+def _meta(self):
+    assert isinstance(self, Atom)
+    return self.meta()
+
+@extend(proto._with_meta, Atom)
+def _with_meta(self, meta):
+    assert isinstance(self, Atom)
+    return self.with_meta(meta)
 
 @as_var("atom")
 def atom(val=nil):

tests/pixie/tests/test-stdlib.pxi

@@ -683,11 +683,12 @@
   (t/assert= 5 ((comp inc inc inc inc) 1))
   (t/assert= :xyz ((comp) :xyz)))
 
-(t/deftest test-swap-reset
+(t/deftest test-atom
   (let [a (atom 0)]
     (t/assert= 1 (swap! a inc))
     (t/assert= 2 (swap! a inc))
-    (t/assert= 3 (reset! a 3))))
+    (t/assert= 3 (reset! a 3))
+    (t/assert= :bar (-> a (with-meta {:foo :bar}) meta :foo))))
 
 (t/deftest pre-post-conds
   (let [f (fn ([a] {:pre [(even? a)] :post [(= % 6)]} (/ a 2))