def param_gen(paramtypes):
    """Generate dictionary of definitions in *paramtypes* list."""

    defs = OrderedDict()
    for paramtype in paramtypes:
        for datatype in ["bool", "int", "str"]:
            if datatype == "int":
                default = 42
            elif datatype == "str":
                default = "hello"
            else:
                default = True
            defs[paramtype + "_" + datatype] = {
                "datatype": datatype,
                "default": default,
                "description": "",
                "paramtype": paramtype,
            }
    return defs