RE: runtine instanciation

["Robert C. Leif" <rleif@rleif.com>]

From: Bob Leif
To: Dmitry Kazakov et al.
1) I do not believe that sacrificing the reliability of the entire
program by switching to SmallTalk is a reasonable solution.

2) Even if I create a tagged type for my record, I still have to fill
its fields. As I previously stated, the allowable data types and their
methods have been previously compiled. I realize that one could use
access types. However, I am hoping for a very simple static solution
based on the use of the compiler. I believe that this is now well within
the capabilities of the combination of modern Ada compilers and our PCs,
which now have capabilities well beyond those envisaged by the original
creators and users of Ada. I ran RR on an 8088 based 4.88 megahertz PC
with I believe 256 K of RAM. I now, in order to run COTs products, have
a computer with half a Gig of RAM and a 1.6 Gigahertz CPU. The bus width
has now been expanded from 1 to 4 or 8 bytes. I suspect that the linker
technology is the part that may have to be modified.

-----Original Message-----
From: comp.lang.ada-admin@ada.eu.org
[mailto:comp.lang.ada-admin@ada.eu.org] On Behalf Of Dmitry A.Kazakov
Sent: Monday, June 17, 2002 3:04 PM
To: comp.lang.ada@ada.eu.org
Subject: RE: runtine instanciation

Robert C. Leif wrote:

> From: Bob Leif
> To: Dmitry Kazakov et al.
> I suspect that in many cases there is a very straightforward approach
to
> accomplish the equivalent of runtime instantiation. In my own work on
> the creation of a new bioinformatics standard, CytometryML, I have a
> requirement to create an array of records, which can have up to 15
> fields. Each of the data types for the fields (parameters) will be
> represented by a compiled package with a complete set of specific
> operations. However, the user (customer) at runtime will have the
> prerogative of selecting from 1 to 15 of these parameters to include
in
> the record. Fortunately, this is directly analogous to the creation of
> the data type in a database. It does NOT have to occur
instantaneously.
> Conceivably, the user could wait about a minute for this to occur. I
> would like to be able to compile and link the instantiation of the
> record and the array. Parenthetically, I am quite willing, if need be,
> to precompile 15 generic packages of records, which have from one to
> fifteen fields and instantiate only one of them. The 15 generic
records
> perhaps could also be included in one package.
> 
> Another similar problem, is to create a calculation program in Ada
that
> is very general for evaluating a mathematical expression. If the
> expression can be converted to an Ada function, why not just compile
it?
> 
> I believe Rational and DEC had incremental compilers. Could this
> facility be made available, even in a space inefficient form, in one
of
> the Ada 95 compilers? This approach has a significant potential
> commercial benefit for the vendors. It would require a runtime version
> of their compilers, which could be licensed for a fee to be ultimately
> paid by the end users of the program.
> 
> Before any of the real-time enthusiasts become upset by this proposal,
> please remember, that this is not to be applied to the run-time
> operations of mission critical applications where execution time and
> scheduling are important.

Well, if performance is not an issue, why not to use class-wide objects 
instead of genericity? Doing so you would not need to instantiate
anything. 
In fact no automatic instantiation would help if the types are unknown
in 
advance. A brute force, like an integrated compiler might help, but I
think 
it would be better to advance ADT to solve problems like that. [ Those
who 
disagree may just switch to SmallTalk. (:-)) ]

-- 
Regards,
Dmitry Kazakov
www.dmitry-kazakov.de