On 4/28/11 11:12 AM, Alexander Belopolsky wrote:
The problem with faithfully implementing IEEE 754 in Python is that exceptions in IEEE standard don't have the same meaning as in Python. IEEE 754 requires that a value is computed even when the operation signals an exception. The program can then decide whether to terminate computation or propagate the value. In Python, we have to choose between raising an exception and returning the value. We cannot have both. It appears that in most cases IEEE 754 "INVALID" exception is treated as a terminating exception by Python and operations that signal INVALID in IEEE 754 raise an exception in Python.
This is not true. In fact, in most cases that issue an INVALID exception are passed silently in Python. See my response to Guido elsewhere in this thread for a nearly complete list. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco