Integer functions

Adds support (freezing, typing, printing) for the following integer functions from sympyextensions.integer_functions:

• bit_shift_left
• bit_shift_right
• bitwise_and
• bitwise_or
• bitwise_xor
• int_div
• int_power_of_2
• modulo_floor

The following are left for future work because they can be conveniently implemented with an if expression (the ternary if operator ?: in C) which is currently not available.

• modulo_ceil
• div_ceil

div_floor is also not implemented because to me the semantics of this function are unclear. Is it supposed to compute \lfloor \frac ab \rfloor (as the name suggests) or the C-like round-to-zero integer division (as the documentation suggests)?

The typifier tries to infer the integer type of the arguments/result and always raises if the type is non-integer. Note that this can lead to cases in which an exception is raised because the inference fails. For example int_div(2, 3) where both arguments are untyped constants. This could be improved in the typifier, e.g. by adding type constraints to deferred constants (also left for future work).

src/pystencils/backend/ast/expressions.py

@@ -485,6 +485,44 @@ class PsDiv(PsBinOp):
     pass
 
 
+class PsIntDiv(PsBinOp):
+    """C-like integer division (round to zero)."""
+
+    #  python_operator not implemented because both floordiv and truediv have
+    #  different semantics.
+    pass
+
+
+class PsLeftShift(PsBinOp):
+    @property
+    def python_operator(self) -> Callable[[Any, Any], Any] | None:
+        return operator.lshift
+
+
+class PsRightShift(PsBinOp):
+    @property
+    def python_operator(self) -> Callable[[Any, Any], Any] | None:
+        return operator.rshift
+
+
+class PsBitwiseAnd(PsBinOp):
+    @property
+    def python_operator(self) -> Callable[[Any, Any], Any] | None:
+        return operator.and_
+
+
+class PsBitwiseXor(PsBinOp):
+    @property
+    def python_operator(self) -> Callable[[Any, Any], Any] | None:
+        return operator.xor
+
+
+class PsBitwiseOr(PsBinOp):
+    @property
+    def python_operator(self) -> Callable[[Any, Any], Any] | None:
+        return operator.or_
+
+
 class PsArrayInitList(PsExpression):
     __match_args__ = ("items",)