Adding most of the mutating methods from BitArray (but now return new…

… Bits).

Adding tests from test_bitstream.py.

bitformat/__init__.py

@@ -114,7 +114,7 @@ def bool_bits2chars(_: Literal[1]):
                     allowed_lengths=(16, 32, 64), description="a big-endian floating point number"),
     # Other known length types
     DtypeDefinition('bits', Bits._setbits, Bits._getbits, Bits, False, bits_bits2chars,
-                    description="a bitstring object"),
+                    description="a Bits object"),
     DtypeDefinition('bool', Bits._setbool, Bits._getbool, bool, False, bool_bits2chars,
                     allowed_lengths=(1,), description="a bool (True or False)"),
     DtypeDefinition('bytes', Bits._setbytes, Bits._getbytes, bytes, False, bytes_bits2chars,

bitformat/array_.py

@@ -449,7 +449,7 @@ def _apply_bitwise_op_to_all_elements_inplace(self, op, value: BitsType) -> Arra
         """Apply op with value to each element of the Array as an unsigned integer in place."""
         value = Bits._create_from_bitstype(value)
         if len(value) != self._dtype.length:
-            raise ValueError(f"Bitwise op needs a bitstring of length {self._dtype.length} to match format {self._dtype}.")
+            raise ValueError(f"Bitwise op needs a Bits of length {self._dtype.length} to match format {self._dtype}.")
         for start in range(0, len(self) * self._dtype.length, self._dtype.length):
             self._data.setitem(slice(start, start + self._dtype.length), op(self._data.getslice(start, start + self._dtype.length), value._bitstore))
         return self