Re: Why no Ada.Wide_Directories?

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

Le Thu, 20 Oct 2011 16:31:59 +0200, Dmitry A. Kazakov  
<mailbox@dmitry-kazakov.de> a écrit:
> I am not a language designer. I have problems rather than solutions.
Like many of us here ;)

> What I know is that the decomposition shall go along the types.
You use to say you don't feel FP good, but I sware, I am sure you would  
enjoy some part of it ;)

> Implementation must be absolutely free too
> choose. There shall be no procedures but operations on types. All types
> shall have classes.
What's missing from Interface type introduced with Ada 2005 ? Doesn't it  
fulfill the above expectations ? (also keep in mind sometime efficiency is  
required, and if you want place formalism over efficiency, then you have  
to sacrifice efficiency, conscientiously).

> Any syntax sugar (prefix notation, infix operations,
> assignments, indexing, member extraction, aggregates, entries,  
> attributes) shall be operations.
Are you sure you are not confused between concrete syntax and abstract  
syntax ? Otherwise, if I may reword you, perhaps you are complaining there  
are not enough user re-definable operations. Otherwise, I don't see what's  
relevant in turning syntactic sugar into operations; these plays two  
different roles and are of orthogonal domains.

> Construction model must be type safe (in particular,
> each type must have constructors, including class-wide types). The type
> system shall support both specialization and generalization.
Could you provide an example case of generalization you have in mind ?

> The programmer
> should be able to enforce static type and constraint checks, in  
> particular,
> to convert any potentially dynamic checks into compile-time errors. All
> exceptions must be typed, contracted and statically checked.
This is not a language topic, instead, a technology level topic. I feel  
runtime check is a reasonable fall-back for what cannot be statically  
checked in th actual state of the technology. If you really require static  
check, then you must restrict yourself to what can be statically checked.  
If Ada 2012 defines some Design by Contract checks as runtime check, this  
is not a language flaw, a pragmatic choice. Along with that, if a compiler  
is able to statically check what Ada 2012 designate as runtime check, then  
nothing in the language definition disallows the compiler to apply all  
static checks it is able to.


-- 
“Syntactic sugar causes cancer of the semi-colons.”  [Epigrams on  
Programming — Alan J. — P. Yale University]
“Structured Programming supports the law of the excluded muddle.” [Idem]
Java: Write once, Never revisit