[cap-talk] Structured types

[Valerio Bellizzomi]

On 13/12/2007, at 13.38, Jonathan S. Shapiro wrote:

>On Thu, 2007-12-13 at 19:22 +0100, Valerio Bellizzomi wrote:
>> On 13/12/2007, at 0.15, Mathieu Suen wrote:
>> >But can you tell me which security bugs that a static type language  
>> >can prevent that dynamicaly type system can't?
>> 
>> Most of the bugs that are hidden behind control-flow gaps.
>
>I am about to ramble for a moment, and what follows may be utter crap,
>but here it goes.
>
>Modern, statically typed, safe programming languages universally include
>dynamic typing in a limited way. The problem is unions, and the need to
>ensure that the union tag field has been properly checked when code
>operates on that union leg. ML, Haskell, BitC, and so forth all perform
>checks of this sort.

I think the "union" type is what in Pascal is called "tagged record".


val