Re: [Haskell-cafe] Design Question - Functions taking 'subtype' like arguments but has to be restricted to one type

Beware: if you go with Either and combine Either ops with >>=, first Left result stops evaluation and returns 1st Left result. Right results continue evaluation. If this is expected, Either fits. If more ops are expected after 'update count' no-op (if Left stands for Frozen), then Either and >>= should not be used together. Algebraic type (Flex count | Frozen count) is also suitable. Let the calling functions decide how to process Frozen values. At least they'll know the difference.