Re: YY_SCANNER_SKELETON.yy_content_area could be ABSTRACT_SPECIAL ?

>>>>> "Eric" == Eric Bezault <[email protected]> writes:

    Eric> In my mind, it has always been clear that we should use
    Eric> SPECIAL for efficency reason. The reason why this could be
    Eric> bypassed is that at the time of writing some of the
    Eric> supported Eiffel compilers did not support SPECIAL. Using
    Eric> ABSTRACT_SPECIAL is not really a solution because it
    Eric> introduces polymorphism, hence reducing the performance that
    Eric> we want to gain by using SPECIAL directly.

But with SPECIAL comes the need for a copy. Which is a bit slow
especially in debug mode. It's not a huge problem, but it would be
nice if SPECIAL had a fast way to copy data from a given pointer.


    Eric> YY_SCANNER_SKELETON has been changed in such as way because
    Eric> during the current migration to void-safety
    Eric> KI_CHARACTER_BUFFER.as_special has been turned to return a
    Eric> non-void SPECIAL. I think that the problem comes from
    Eric> here. Your version of class buffer is now likely to violate
    Eric> this new postcondition in `as_special'.

Indeed, saw the comment and I indeed inherit from KI_CHARACTER_BUFFER.


    Eric> I'll see what I can do to revert this change. I must say
    Eric> that I'm not a fan of all this void-safety thing. For code
    Eric> that was well equipped with assertions like the Gobo
    Eric> libraries, converting to void-safety makes the code more
    Eric> convoluted, hence harder to read and maintain.

Interesting perspective.

But I suppose it's a hard call. Without SPECIAL reading from the might
be a bit slower, but if you need t copy to special first + read
from SPECIAL I think the overall case has become a bit slower.
-- 
Cheers,

Berend de Boer

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