Optimisation of unpackCString#

[Neil Mitchell]

Hi

> You'd have to conditionally use overloaded strings in GHC only.
>  I'm not sure it would work ( can you quantify the cost of not being able
>  to take head at compile time? )

The cost of not having this is probably ~10x slower for the tagsoup
library :-( - i.e. pretty huge. I'm looking at other ways of doing
this, perhaps using a preprocessor or something - which would be more
robust than RULES and perhaps generalise in other nice ways.

Thanks

Neil