I was just playing around with some edge cases on the float/double argument
support. There are some problems involved with out-of-range values that
need to be addressed and they should be addressed consistently. There are
basically two issues. 1) How to deal with values getting passed out as
arguments and 2) Dealing with the edge cases of values getting passed back
in.
On outbound values, the code for doubles is checking to see if the converted
value is +infinity or -infinity, and raises an error in either case. ooRexx
numbers outside of the valid range result in that, so an error is raised.
Float, on the other hand, calls the double conversion routine and then casts
the double value to a float. There's no checking for the infinities at this
boundary, so the infinities will get passed as arguments in the float case.
Easy enough to add a check so this is consistent, but this begs the question
of whether we might actually want to allow the infinity values to get passed
through. My gut instinct is no, and it's generally easier to lift an
restriction than to impose one at a later time, so it can't hurt to keep
this an error. An error is also consistent with how integer value arguments
are handled.
The other issue is how we should be dealing with these edge values when they
are a return value. Currently, there are no return value cases that result
in an error getting raised. I also had to deal with one of the edge cases
with RxMath already, since nan gets returned by some of the library
functions. This used to be somewhat inconsistent because it depended upon
how the underlying libraries worked. On Windows, the nan cases returned the
string "ERROR" and on Linux you got the string "nan". I fixed this in the
infrastructure by having a nan value map to the character string "nan". I
can do the same for "+infinity" and "-infinity" in the infrastructure if we
agree that's the desired behavior. Right now, it appears that at least for
the float tests, a returned infinity is getting formatted as a "1", which is
definitely not a correct result.
So, to sumerize, the questions are:
1) How should out of range double and float arguments be handled?
2) How should we handle nan, +infinity and -infinity as return values.
Rick
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