Re: S-expression I/O in Ada

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Mon, 09 Aug 2010 23:54:00 +0200, _FrnchFrgg_ wrote:

> Le 09/08/2010 21:59, Dmitry A. Kazakov a �crit :
> 
>>> Yeah, that's a shame.  I'd like to have case statements
>>> on bit maps, but also on other composite types.
>>
>> Yes, it is a type property that the domain is a set of identifiable values,
>> in fact, some mapping to an enumeration.
>>
>> The language should provide means to implement this interface with any
>> type. E.g. why I cannot specify this interface for String to be able to
>> write:
>>
>>     case Get_Token is
>>         when "type" =>  ...
>>         when "package" =>  ...
>>         when others =>  raise Syntax_Error;
>>     end case;
> 
> I think that you want pattern matching 
> (http://en.wikipedia.org/wiki/Standard_ML#Algebraic_datatypes_and_pattern_matching)

No, I don't believe in type inference, in fact I strongly disbelieve in it. 

What I want is a manifested strong type system properly done. The above
does not require matching all types involved were known in advance. It
requires some enumeration of strings (like hash function), which the
compiler could use in order to build the case statement.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de