On Tue, Oct 28, 2014 at 6:43 PM, Michael Snoyman
As I recently commented on this list[1], the Show typeclass is overloaded with multiple meanings (serialization, debug info, and user-friendly data display). The general consensus seems to be that the official semantics for Show should be for serialization (as paired up with Read).
A bit off topic but, I think the semantics of Show/Read should actually be even stronger. Serializing to a String is a bit pointless -- things like Binary, Cereal, SafeCopy etc are much more suited for 'serialization'. It seems to me that Show and Read are really closer to ShowExpr and ReadExpr in many cases. The idea being that you can show a value, copy and paste that string into GHCi and get back your original value. For many show instances this holds true. Though clearly not all. I'd love to see: 1. Show/Read really be ShowExpr/ReadExpr 2. Binary 3. SafeCopy (like binary, but versioned with migration) 4. Pretty Of course, that opens the can of worms -- why not HTML instances, Markdown instances, etc. This is probably more a proposal for something like Idris where changes like this are still viable ;) - jeremy