... anything else #

Similar to C-style languages' default case, joelang's ... case handles a value not defined in one of the previous cases.

It must be the last case in then when.

const hex = when someString {
    'red' -> '#ff0000',
    'burnt-orange' -> '#cc5500',
    ... -> '##ffffff', // some default
};

Requirement #

The ... case is required in all whens, except for a bool, for example:

when someBool {
    true -> do(),
    false -> doNot(),
};