Re: Seeking for papers about tagged types vs access to subprograms

["Yannick Duchêne (Hibou57)" <yannick_duchene@yahoo.fr>]

Le Fri, 10 May 2013 09:48:26 +0200, Dmitry A. Kazakov  
<mailbox@dmitry-kazakov.de> a écrit:
>> Typing is too rigid to do a good job
>
> Typing is necessarily rigid because

I think he meant something else when he said “rigid”. I understood he  
meant “not expressive enough”, “not always applicable”. I would say  
“limited” (which is less ambiguous, except in terms of Ada wordings).

> it is on the next, higher level of
> power. Types describe the behavior of sets of values. Nothing you can do
> with individual values could come even close to that, except for trivial
> cases like enumeration types.

To be able to apply types beyond trivial cases, would need to have types  
beyond trivial types. If it is supposed type must be as they already are,  
there is not solution. If it is supposed the concept of type must be  
defined, I would say it is what holds a set of axioms which will be  
automatically pulled in a context with each reference to that type.  
Actually, and except with discriminated records and pre/post condition  
(which are not statically checked), the only static capability of types,  
is to enumerate a simple list of values and list operations applicable to  
that list of values. That's indeed too limited except for trivial cases.

-- 
“Syntactic sugar causes cancer of the semi-colons.” [1]
“Structured Programming supports the law of the excluded muddle.” [1]
[1]: Epigrams on Programming — Alan J. — P. Yale University