[Haskell-cafe] instance Binary UTCTime (Was: Oprhan instances)

Daniel Fischer daniel.is.fischer at web.de
Thu Nov 26 15:58:41 EST 2009


Am Donnerstag 26 November 2009 21:27:53 schrieb Joachim Breitner:
> I still have doubts that this approach will scale as hackage grows.

True. I gratuitously assumed that one would ask only if one believes such an instance 
would be *generally* useful, not only for the one project at hand. That would entail that 
one would only ask for instances of the more prominent classes (Show, Read, Eq, Ord, 
Numerical classes, Monad, Functor, Applicative*; Binary would qualify too, I believe).

> We’d get a lot more dependencies than we have now, and still would face this
> problem every now and then. Or do you really want packages that provide
> data types (like time) depend on all the libraries that do some kind of
> conversion (binary, html, xhtml, json, yaml, etc.)?

No, that'd be too much indeed.

* that list is not meant to be exhaustive, just what sprang to mind.


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