Re: [Haskell-cafe] ANNOUNCE: vector-bytestring-0.0.0.0

On Oct 19, 2011, at 7:32 AM, Ivan Lazar Miljenovic wrote:

On 19 October 2011 22:09, Roman Leshchinskiy wrote:

...

So it seems that (1) people have very different requirements and (2) the Show instance only really matters for debugging in ghci. Here is a thought. What if ghci allowed Show instances to be overridden dynamically? So you could put your preferred Show instance for Vector Word8 in you .ghci file and ghci would use that when displaying stuff (but not when actually evaluating things). Would that solve most of the problems without messing with vector's Show instances?

Would this hypothetical ghci feature also work for cases where you have a ByteString as part of another type that derives Show and Read?

I also wonder whether it would suffice to have a ByteString -> String function available rather than requiring Show per-se for the case of a ByteString on its lonesome.

Note that other programming languages have had to solve this exact problem and they usually end up with multiple functions- one for debugging, one for serialization, one for displaying how the object was constructed. For example, in Python, look at: http://docs.python.org/reference/datamodel.html#object.__repr__ http://docs.python.org/reference/datamodel.html#object.__str__ Cheers, M