Python from Wise Guy's Viewpoint

[Pascal Costanza]

Andreas Rossberg wrote:

> Pascal Costanza wrote:
> 
>>
>> Can you show me an example of a program that does't make sense anymore 
>> when you strip off the static type information?
> 
> 
> Here is a very trivial example, in SML:
> 
>     20 * 30
> 
> Multiplication, as well as literals, are overloaded. Depending on 
> whether you type this expression as Int8.int (8-bit integers) or 
> IntInf.int (infinite precision integer) the result is either 600 or an 
> overflow exception.
> 
> So the program does not make sense without type information, because it 
> does not have an unambiguous (i.e. no) semantics.
> 
> I'm ready to admit that it may be a dubious example of a typing feature. 
> But it is simple, and clearly sufficient to disprove your repeated claim 
> that static types don't add expressiveness to a language. If you did not 
> have them for the example above, you needed some other feature to 
> express the disambiguation.

Sorry, do you really want to say that I can't make my program throw an 
exception when some variables are not inside a specified range?

(assert (typep (* 20 30) '(integer 0 255)))


Pascal