Re: Rational for not making cursor tagged in Containers

[Maciej Sobczak <no.spam@no.spam.com>]

Dmitry A. Kazakov wrote:

> A confusion is in assumption that some arguments of an operation are more
> arguments than others.

There is some rationale for this, however.
With the traditionally abstract OO, operations are executed as a result 
of messages that are sent to objects. Now that indeed gives some objects 
more focus than others.

This:

a.op(b);

means (supposedly) that "op" message is sent to object "a" and the 
payload of the message is "b".

I agree that it introduces some asymetry that is not necessarily needed.
I mean - the above abstraction is not necessarily the best one, but 
serves me well as an explanation of the a.op(b) issue.

> Another is that primitive operations belong to the
> object (instance).

No, but it makes sense to think that they belong to the type of some object.

> The third confusion raises from incompatibility of the
> prefix notation with multi-methods and multiple dispatching operations.

True. But then, the above messaging abstractions needs to be extended to 
cover "multicasts". :-)

>> Other
>> advantage of prefix notation is that I do not have to fully qualify
>> nor apply use clause.
> 
> When there is something wrong with use-clauses *that* should be fixed.

I agree that the lack of ADL (Argument-Dependent Lookup) in Ada sucks.

-- 
Maciej Sobczak : http://www.msobczak.com/
Programming    : http://www.msobczak.com/prog/