Switch otherwise

IDSTAT-6
TitleEvery switch shall have an otherwise section.
PriorityStrongly recommended
DescriptionEvery switch shall have an otherwise section, even if it does not contain executable code.
That way, no execution paths are overlooked.
RationaleCompleteness, Readability

Avoid:

switch reply
    case "Yes"
        saveData()
    case "No"
        clearData()
end

Instead use:

switch reply
    case "Yes"
        saveData()
    case "No"
        clearData()
    otherwise
        % Should not get here.
        error("Unknown reply " + reply)
end