On 22 Sep 2009, at 17:46 , Steven D'Aprano wrote:
On Wed, 23 Sep 2009 12:25:32 am Masklinn wrote:
On 22 Sep 2009, at 15:16 , Steven D'Aprano wrote:
On Tue, 22 Sep 2009 01:05:41 pm Mathias Panzenböck wrote:
I don't think this is a valid test to determine how a language is typed. Ok, C++ is more or less weakly typed (for other reasons), but I think you could write something similar in C#, too. And C# is strongly typed.
Weak and strong typing are a matter of degree -- there's no definitive test for "weak" vs "strong" typing, only degrees of weakness. The classic test is whether you can add strings and ints together, but of course that's only one possible test out of many.
And it's a pretty bad one to boot: both Java and C# allow adding strings and ints (whether it's `3 + "5"` or `"5" + 3`) (in fact they allow adding *anything* to a string), but the operation is well defined: convert any non-string involved to a string (via #toString ()/.ToString()) and concatenate.
I don't see why you say it's a bad test. To me, it's a good test, and Java and C# pass it.
Uh no, by your criterion they fail it: both java and C# do add strings and integers without peeping.
If you're only criterion is that an operation is well-defined, then "weak typing" becomes meaningless: I could define addition of dicts and strings to be the sum of the length of the dict with the number of hyphens in the string, and declare that
{'foo':'a', 'bar':'b'} + "12-34-56-78-90"
returns 6, and by your criterion my language would be strongly typed. I think that makes a mockery of the whole concept. I don't think I defined any criterion of strong/weak typing. As far as I'm concerned, and as I've already mentioned in this thread, the whole weak/strong axis is meaningless and laughable.
This heuristic is not arbitrary. Of course it is.
Automatically converting ints to floats is mathematically reasonable, because we consider e.g. 3 and 3.0 to be the same number. Do we? Given 3/2 and 3.0/2 don't necessarily give the same answer (some languages don't even consider the first operation valid), I'm not sure we do.
Perl is weakly typed but it's very hard to cause it to crash, See the link I previously gave, you might consider Perl weakly typed, not everybody does.
while C++ is strongly typed but easy to cause it to core-dump. See my response to your previous declaration.