[WIP] Implement simple subroutine opcodes]

eth/vm/computation.py

@@ -324,6 +324,17 @@ def stack_push_int(self) -> Callable[[int], None]:
     @cached_property
     def stack_push_bytes(self) -> Callable[[bytes], None]:
         return self._stack.push_bytes
+
+    #
+    # Return Stack Management
+    #
+    @cached_property
+    def rstack_push_int(self) -> Callable[[int], None]:
+        return self._rstack.push_int
+
+    @cached_property
+    def rstack_pop1_int(self) -> Callable[[int]], None]:
+        return self._rstack.pop1_int
 
     #
     # Computation result

eth/vm/rstack.py

@@ -23,6 +23,13 @@
 For the same reason, the class RStack doesn't inherit from the abc StackAPI, as it would require to implement all the abstract methods defined.
 """
 
+
+def _busted_type(item_type: type, value: Union[int, bytes]) -> ValidationError:
+    return ValidationError(
+        "Stack must always be bytes or int, "
+        f"got {item_type!r} type, val {value!r}"
+    )
+
 class RStack():
     """
     VM Return Stack
@@ -46,7 +53,7 @@ def push_int(self) -> int:
         self._append((int, value))
 
 
-def pop1_int(self) -> int:
+    def pop1_int(self) -> int:
         #
         # Note: This function is optimized for speed over readability.
         #
@@ -61,10 +68,3 @@ def pop1_int(self) -> int:
             else:
                 raise _busted_type(item_type, popped)
 
-def _busted_type(item_type: type, value: Union[int, bytes]) -> ValidationError:
-    return ValidationError(
-        "Stack must always be bytes or int, "
-        f"got {item_type!r} type, val {value!r}"
-    )
-
-