Expert system for writing programs?

I am brainstorming an idea of developing a high level software to manipulate matrix algebra equations, tensor manipulations to be exact, to produce optimized C++ code using several criteria such as sizes of dimensions, available memory on the system, etc.

Something which is similar in spirit to tensor contraction engine, TCE, but specifically oriented towards producing optimized rather than general code. The end result desired is software which is expert in producing parallel program in my domain.

• Does this sort of development fall on the category of expert systems?
• What other proje开发者_C百科cts out there work in the same area of producing code given the constraints?

What you are describing is more like a Domain-Specific Language.

http://en.wikipedia.org/wiki/Domain-specific_language

It wouldn't be called an expert system, at least not in the traditional sense of this concept.

Expert systems are rule-based inference engines, whereby the expertise in question is clearly encapsulated in the rules. The system you suggest, while possibly encapsulating insight about the nature of the problem domain inside a linear algebra model of sorts, would act more as a black box than an expert system. One of the characteristics of expert systems is that they can produce an "explanation" of their reasoning, and such a feature is possible in part because the knowledge representation, while formalized, remains close to simple statements in a natural language; matrices and operations on them, while possibly being derived upon similar observation of reality, are a lot less transparent...

It is unclear from the description in the question if the system you propose would optimize existing code (possibly in a limited domain), or if it would produced optimized code, in that case driven bay some external goal/function...

Well production systems (rule systems) are one of four general approaches to computation (Turing machines, Church recursive functions, Post production systems and Markov algorithms [and several more have been added to that list]) which more or less have these respective realizations: imperative programming, functional programming, rule based programming - as far as I know Markov algorithms don't have an independent implementation. These are all Turing equivalent.

So rule based programming can be used to write anything at all. Also early mathematical/symbolic manipulation programs did generally use rule based programming until the problem was sufficiently well understood (whereupon the approach was changed to imperative or constraint programming - see MACSYMA - hmmm MACSYMA was written in Lisp so perhaps I have a different program in mind or perhaps they originally implemented a rule system in Lisp for this).

You could easily write a rule system to perform the matrix manipulations. You could keep a trace depending on logical support to record the actual rules fired that contributed to a solution (some rules that fire might not contribute directly to a solution afterall). Then for every rule you have a mapping to a set of C++ instructions (these don't have to be "complete" - they sort of act more like a semi-executable requirement) which are output as an intermediate language. Then that is read by a parser to link it to the required input data and any kind of fix up needed. You might find it easier to generate functional code - for one thing after the fix up you could more easily optimize the output code in functional source.

Having said that, other contributors have outlined a domain specific language approach and that is what the TED people did too (my suggestion is that too just using rules).