unsigned integers

README.md

@@ -60,6 +60,8 @@ class Foo(EnvExperiment):
     * `bool`
     * `int32`
     * `int64`
+    * `uint32`
+    * `uint64`
     * `float`
     * `str` (note: fixed length, provide builtin methods?)
     * `bytes`
@@ -79,7 +81,7 @@ class Foo(EnvExperiment):
       i = 0
       a = t[i]
       ```
-    * `range` (over `int32`, `int64`, `float`)
+    * `range` (over numerical types)
 
 ## Generics
 We use [type variable](https://docs.python.org/3/library/typing.html#typing.TypeVar) for denoting generics.