Fix bitwise operations (#31)

* xxx.isna()

* isna for unicode/obj

* fix test for py3.7

* make boolean wrapping of bitwise operations optional

sharrow/aster.py

@@ -337,6 +337,7 @@ def __init__(
         preferred_spacename=None,
         extra_vars=None,
         blenders=None,
+        bool_wrapping=False,
     ):
         self.spacename = spacename
         self.dim_slots = dim_slots
@@ -347,6 +348,7 @@ def __init__(
         self.preferred_spacename = preferred_spacename
         self.extra_vars = extra_vars or {}
         self.blenders = blenders or {}
+        self.bool_wrapping = bool_wrapping
 
     def log_event(self, tag, node1=None, node2=None):
         if logger.getEffectiveLevel() <= 0:
@@ -691,7 +693,7 @@ def visit_Name(self, node):
 
     def visit_UnaryOp(self, node):
         # convert bitflip `~x` operator into `~np.bool_(x)`
-        if isinstance(node.op, ast.Invert):
+        if self.bool_wrapping and isinstance(node.op, ast.Invert):
             return ast.UnaryOp(
                 op=node.op,
                 operand=bool_wrap(self.visit(node.operand)),
@@ -707,7 +709,9 @@ def visit_BinOp(self, node):
         left = self.visit(node.left)
         right = self.visit(node.right)
 
-        if isinstance(node.op, (ast.BitAnd, ast.BitOr, ast.BitXor)):
+        if self.bool_wrapping and isinstance(
+            node.op, (ast.BitAnd, ast.BitOr, ast.BitXor)
+        ):
 
             result = ast.BinOp(
                 left=bool_wrap(left),
@@ -924,6 +928,7 @@ def expression_for_numba(
     prefer_name=None,
     extra_vars=None,
     blenders=None,
+    bool_wrapping=False,
 ):
     """
     Rewrite an expression so numba can compile it.
@@ -958,6 +963,7 @@ def expression_for_numba(
             prefer_name,
             extra_vars,
             blenders,
+            bool_wrapping,
         ).visit(ast.parse(expr))
     )
 

sharrow/digital_encoding.py

@@ -234,6 +234,10 @@ def set(self, name, *args, **kwargs):
         by_dict : {8, 16, 32}, optional
             Encode by dictionary, using this bitwidth.  If given, all
             arguments other than this and `x` are ignored.
+        joint_dict : bool or str, optional
+            If given as a string, the variables in `name` will be encoded
+            with joint dictionary encoding under this name.  Or simply give
+            a `True` value to apply the same with a random unique name.
 
         Returns
         -------
@@ -287,6 +291,22 @@ def baggage(self, names):
 
 
 def multivalue_digitize_by_dictionary(ds, encode_vars=None, encoding_name=None):
+    """
+    Apply a joint dictionary encoding to a collection of Dataset variables.
+
+    Parameters
+    ----------
+    ds : Dataset
+    encode_vars : Collection[str], optional
+        The collection of dataset variable names that will be encoded with
+        a joint dictionary.
+    encoding_name : str, optional
+        Use this name for the newly created joint encoding.
+
+    Returns
+    -------
+
+    """
     logger = logging.getLogger("sharrow")
     if not isinstance(encoding_name, str):
         i = 0

sharrow/flows.py

@@ -582,6 +582,7 @@ def __new__(
         hashing_level=1,
         dim_order=None,
         dim_exclude=None,
+        bool_wrapping=False,
     ):
         assert isinstance(tree, DataTree)
         tree.digitize_relationships(inplace=True)
@@ -603,6 +604,7 @@ def __new__(
             boundscheck=boundscheck,
             nopython=nopython,
             fastmath=fastmath,
+            bool_wrapping=bool_wrapping,
         )
         # return from library if available
         if flow_library is not None and self.flow_hash in flow_library:
@@ -641,6 +643,7 @@ def __initialize_1(
         hashing_level=1,
         dim_order=None,
         dim_exclude=None,
+        bool_wrapping=False,
     ):
         """
         Initialize up to the flow_hash
@@ -660,6 +663,7 @@ def __initialize_1(
         self._secondary_flows = {}
         self.dim_order = dim_order
         self.dim_exclude = dim_exclude
+        self.bool_wrapping = bool_wrapping
 
         all_raw_names = set()
         all_name_tokens = set()
@@ -776,6 +780,7 @@ def _flow_hash_push(x):
         _flow_hash_push(f"boundscheck={boundscheck}")
         _flow_hash_push(f"error_model={error_model}")
         _flow_hash_push(f"fastmath={fastmath}")
+        _flow_hash_push(f"bool_wrapping={bool_wrapping}")
 
         self.flow_hash = base64.b32encode(flow_hash.digest()).decode()
         self.flow_hash_audit = "]\n# [".join(flow_hash_audit)
@@ -873,6 +878,7 @@ def init_sub_funcs(
                             digital_encodings=digital_encodings,
                             extra_vars=self.tree.extra_vars,
                             blenders=blenders,
+                            bool_wrapping=self.bool_wrapping,
                         )
                     except KeyError as key_err:
                         if ".." in key_err.args[0]:
@@ -896,6 +902,7 @@ def init_sub_funcs(
                                     prefer_name=other_spacename,
                                     extra_vars=self.tree.extra_vars,
                                     blenders=blenders,
+                                    bool_wrapping=self.bool_wrapping,
                                 )
                             except KeyError as err:  # noqa: F841
                                 pass
@@ -921,6 +928,7 @@ def init_sub_funcs(
                 self.output_name_positions,
                 "_outputs",
                 extra_vars=self.tree.extra_vars,
+                bool_wrapping=self.bool_wrapping,
             )
 
             aux_tokens = {
@@ -936,6 +944,7 @@ def init_sub_funcs(
                 spacevars=aux_tokens,
                 prefer_name="aux_var",
                 extra_vars=self.tree.extra_vars,
+                bool_wrapping=self.bool_wrapping,
             )
 
             if (k == init_expr) and (init_expr == expr) and k.isidentifier():