Instances for data types

Sven Panne Sven.Panne at
Tue Apr 27 22:57:52 EDT 2004

Playing around with System.Posix.Terminal, I realized that there are no Read,
Show, Eq, Enum, ... instances for the data types defined there (TerminalState,
TerminalMode, ...). This is not a very difficult problem to solve in one's
own program, but it's not very handy, either. This raises a general question:
What instances should be defined in the standard libraries for types like
this? A general policy would be a good thing. IMHO, at least Read, Show, Typeable
and Eq could be expected, having Ord, Enum and Bounded, too, would be nice.
Any opinions?


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