_fn.py 文件源码

def _is_ascribed_match_head(cls, e):
        if isinstance(e, ast.Subscript):
            value = e.value
            if cls._is_unascribed_match_head(value):
                slice = e.slice
                if isinstance(slice, ast.Slice):
                    lower, upper, step = slice.lower, slice.upper, slice.step
                    if lower is None and upper is not None and step is None:
                        e.is_match_head = True
                        e.scrutinee = value.scrutinee
                        e.asc_ast = upper
                        return True
                    else:
                        raise _errors.TyError("Invalid ascription format.", slice)
                else:
                    raise _errors.TyError("Invalid ascription format.", slice)
        return False