Add Range (#66)

* Add Range function

Work all done by @sudo-panda

Author: sudo-panda

func_adl/__init__.py

@@ -10,3 +10,5 @@
 
 # Dataset accessors
 from .event_dataset import EventDataset, find_EventDataset  # NOQA
+
+from .functions import Range

func_adl/functions.py

@@ -0,0 +1,24 @@
+import ast
+
+from .object_stream import ObjectStream
+
+from typing import Union, cast
+
+def Range(lower_bound: Union[str, int, ast.AST], upper_bound: Union[str, int, ast.AST]) -> ObjectStream:
+    r"""
+    Given the lower and upper bound return an object with the range of numbers, similar to python range
+    
+    Arguments:
+
+        lower_bound     The start of the range
+        upper_bound     The end of the range
+
+    Return:
+
+        A new ObjectStream that contains the range of numbers
+
+    """
+
+    return ObjectStream(function_call("Range",
+                                          [cast(ast.AST, as_ast(lower_bound)),
+                                           cast(ast.AST, as_ast(upper_bound))]))