parameters

def parameter_specs(func: Callable[..., object]) -> dict[str, type[CGType]]:
    """The ``CGType`` schema each of ``func``'s parameters declares, by name.

    A broadcast value is a schemaless container — ``Map.values()`` and
    ``Array.map`` land in a bare ``Array``, which cannot store itself — so what
    the parameter declares is the schema its argument stores, and hashes, as.
    A parameter that declares a bare container declares no schema either, and
    its argument falls back to hashing as its own type.
    """
    return {
        name: hint
        for name, hint in get_type_hints(func).items()
        if name != "return"
        and isinstance(hint, type)
        and issubclass(hint, CGType)
        and hint not in _SCHEMALESS
    }