Hi
Note that in the bytestring case the compiler doesn't do so, it's the library that does (by telling the compiler to rewrite things with RULEs).
ByteString is in base, and ships with GHC, I think that makes it GHC's fault if it does naughty things.
Unfortunately, it's very appealing in bytestring's case...
Yes, the dilema between performance and purity...
For reference, my Catch tool treats Float/Double compare as never crashing, and division by zero as always crashing
Even for Double/Float?
Yes.
There's also:
Prelude> (minBound :: Int) `div` (-1) *** Exception: arithmetic overflow
but you probably can't do much about that in Catch.
There is an easy solution, always use Integers. Catch also assumes rules like adding two positive numbers results in a positive number - which unfortunately isn't actually true. Thanks Neil