Re: [Haskell-cafe] Where is SNMap for stable names?

On Sat, Sep 24, 2011 at 01:41, Edward Kmett wrote:

You still need IO to get the stable name out to use. :)

I don't understand this statement. Consider the lookup operation in the paper and in your System.Mem.StableName.Map:

lookupSNMap :: SNMap k v -> StableName k -> IO (Maybe v)

lookup :: StableName a -> Map f -> Maybe (f a)

Unless you are intending f to be instantiated to IO -- which is not how I read it -- then, lookupSNMap is requiring some aspect of IO, probably mutability, and lookup is not. I am wondering if there is some fundamental difference between the two. Is the paper using immutability only for performance reasons? In that case, it's not a fundamental difference. Regards, Sean Sent from my iPad

On Sep 23, 2011, at 5:33 AM, Sean Leather wrote:

Hi Edward,

On Thu, Sep 22, 2011 at 16:50, Edward Kmett wrote:

...

I have a "stable-maps" package that provides lookup and inserting into a map via stable names.

The paper mentions the need for a mutable finite map, and all the operations are IO. Do you know why this is and what's different with your pure implementation?

Regards, Sean