On Sun, May 22, 2011 at 12:58 PM, Milan Straka
Do you think we should have different types for static and lazy maps? It feels odd to me to have these distinguished on type level. To me it is more about how you want to work with the structure, not the structure itself.
I've thought about this issue as well. At the moment Data.HashMap.Strict just provides wrappers around the functions in Data.HashMap.Lazy. Two implications of this is that all instances are shared (so a HashMap from Data.HashMap.Strict still behaves like a lazy map when used through class instances) and that it's a bit trickier to get strictness right (while it falls out almost automatically if you make the type itself strict). I also think there's a small performance implication of having the type itself strict, in that GHC never will have to check if the value is evaluated. I need to investigate this some more though. Cheers, Johan