pytype.pytd.visitors.ExpandSignatures

Expand to Cartesian product of parameter types. For example, this transforms def f(x: Union[int, float], y: Union[int, float]) -> Union[str, unicode] to def f(x: int, y: int) -> Union[str, unicode] def f(x: int, y: float) -> Union[str, unicode] def f(x: float, y: int) -> Union[str, unicode] def f(x: float, y: float) -> Union[str, unicode] The expansion by this class is typically *not* an optimization. But it can be the precursor for optimizations that need the expanded signatures, and it can simplify code generation, e.g. when generating type declarations for a type inferencer.