"Rob Thorpe" <[EMAIL PROTECTED]> writes: > Matthias Blume wrote: >> "Rob Thorpe" <[EMAIL PROTECTED]> writes: >> >> > I think we're discussing this at cross-purposes. In a language like C >> > or another statically typed language there is no information passed >> > with values indicating their type. >> >> You seem to be confusing "does not have a type" with "no type >> information is passed at runtime". >> >> > Have a look in a C compiler if you don't believe me. >> >> Believe me, I have. > > In a C compiler the compiler has no idea what the values are in the > program.
It is no different from any other compiler, really. If the compiler sees the literal 1 in a context that demands type int, then it knows perfectly well what value that is. > It knows only their type in that it knows the type of the variable they > are contained within. > Would you agree with that? > >> > No it doesn't. Casting reinterprets a value of one type as a value of >> > another type. >> > There is a difference. If I cast an unsigned integer 2000000000 to a >> > signed integer in C on the machine I'm using then the result I will get >> > will not make any sense. >> >> Which result are you getting? What does it mean to "make sense"? > > Well the right one actually, bad example. > > But, if I cast an unsigned int 2500000000 to signed I get -1794967296. So, why do you think this "does not make sense"? And, as this example illustrates, casting in C maps values to values. Depending on the types of the source and the target, a cast might change the underlying representation, or it might leave it the same. But it does produce a value, and the result value is usually not the same as the argument value, even if the representation is the same. Matthias -- http://mail.python.org/mailman/listinfo/python-list
