Talk:Von Neumann programming languages

Imperative = von Neumann, Functional = non-von Neumann-Languages?

Could you say as a general rule that functional languages are non-von Neumann-languages? For example, is Lisp a von Neumann language? If it is, is Haskell (which is purely functional, as opposed to Lisp) too?

I guess, I'm just asking for more well-known examples of non-von Neumann-Langs.

I was thinking the exact same thing as I was reading the article -- and the answer is a resounding "maybe" :)

Problem is in the definition of "Functional Language" - usually, all Lambda Calculus descendants are called "Functional".

John Backus says functional style is non-von Neumann, but he differentiates it from lambda calc:

"An FP system is founded on the use of a fixed set of combining forms called functional forms. These, plus simple definitions, are the only means of building new functions from existing ones; they use no variables or substitution rules, and they become the operations of an associated algebra of programs. All the functions of an FP system are of one type: they map objects into objects and always take a single argument.

In contrast, a lambda-calculus based system is founded on the use of the lambda expression, with an associated set of substitution rules for variables, for building new functions. The lambda expression (with its substitution rules) is capable of defining all possible computable functions of all possible types and of any number of arguments."

Apparently this is why only SOME functional languages are non-von Neumann. Fry-kun (talk) 08:59, 22 February 2008 (UTC)