>  Uri Guttman  

>  > we are planning automatic over/underflow to bigfloat. so there is no

>  > need for traps. they could be provided at the time of the 

>  > conversion to big*.

>  

>  OK. But will Perl support signaling and non-signaling NANs?


I don't think we should go for automatic overflow/underflow between
float and bigfloat. The float exception (overflow, underflow, inexact,
divide zero, ...) is very difficult to handle. Using Unix signal is 
expensive and very platform-specific (lots of ucontext issues). Since
C language does not support floating-point signal, we may use some
assembly code to handle it, it will be porting nightmare.

Since most of floating-point assumes IEEE-semantics, taking automatic
float/bigfloat will change this assumption significantly. It may a
lot of code and algorithm. I think it is safer just to provide a
BigDecimal class for developers to use, and keep the basic float
semantics (close to 64-bit IEEE-754 if possible).

Hong