First stage of Quesa changes now complete

[Roger H. <rog...@mi...>]

I have now completed the change to use a hierarchy of C++ classes so
that the instance data of each Quesa object is allocated as a single 
block
of memory. In CodeWarrior the class hierarchy window now shows the
full tree of Quesa'a built in classes.

I seek your input on what I have done and in particular could the 
versions
for other platforms and even the Macho target for Mac be tested please.

I suspect the problem with the 'Dump' code has sorted itself out, but 
could
this be checked too please.



For my remaining 'slack' time I would like your opinions on the 
possible use of C++ memory
allocation and construction facilities. On Macintosh I think that using 
statements like:

  E3ClassInfo* theInfo = new E3ClassInfo ;

E3ClassInfo* theClass = (E3ClassInfo*) Q3Memory_AllocateClear ( sizeof 
( E3ClassInfo ) ) ;

are (except for the zeroing of the block of memory) equivalent as they 
both end up calling
malloc to actually reserve the memory. Am I correct, and what is the 
situation on the other
platforms?



The other thing I would like to bring forward from the faster Microspot 
version of Quesa is
the elimination of the hash table search for methods each time they are 
used.

I had originally hoped to use proper C++ virtual methods as these are 
exactly what Quesa
is doing, but collective wisdom was that this was a bad move. An 
alternative is to replicate the
class tree of the instance data with one which has ClassInfo at its 
root. Then there could
be pointers to the member functions introduced at each level of the 
hierarchy, and these
could be initialised with a call to E3ClassInfo::Find_Method which 
would find the appropriate
method (by calling the meta handler for the class and if necessary each 
of its parents until
it finds a method) in exactly the same way as is done now when a method 
is not found in
the hash table.

Your opinions please so I can get on with one or both of these if they 
are felt desirable.




Roger.