def process_param(param, offset):
    """Process a single parameter produced by `get_function_parameter_names`."""
    # Ignore args with default values, since Rope considers them assignments.
    if "=" in param:
        return []

    # Strip off any type annotation.
    first_colon_index = param.find(":")
    if first_colon_index >= 0: # Variables are first in MyPy, reversed from C.
        param = param[:first_colon_index]

    # Strip off beginning whitespace.
    first_non_whitespace_index = len(param) - len(param.lstrip())
    offset += first_non_whitespace_index
    param = param.strip()
    if not param:
        return []
    return [param, offset]