Data.IntMap.Strict.findWithDefault is too strict

[Ben Gamari]

Christian Maeder <Christian.Maeder at dfki.de> writes:

> Hi,
>
> when trying out Data.IntMap.Strict instead of Data.IntMap, I've noticed 
> (after some confusion) that Data.IntMap.Strict.findWithDefault evaluates 
> the default value, even if it is not used!
>
> I usually pass an error-call to IntMap.findWithDefault to get a more 
> informative crash-message than by using IntMap.!
>
I have also found this to be problematic in the past. Is there a
compelling reason to keep the current behavior? I would find this
function far more useful if the default value were lazily evaluated.

Cheers,

- Ben