christopher diggins wrote:
----- Original Message ----- From: "Joel de Guzman" <joel@boost-consulting.com> To: <boost@lists.boost.org> Sent: Wednesday, February 02, 2005 6:32 AM Subject: [boost] Re: Gauging Interest: New Functional Library and Programming Language
christopher diggins wrote: Jeez, you and I should really talk. I have a project started 2 years ago called "Rave" which is reminiscent of this. Example:
object factorial; factorial = if_(_1 == 0) [ 1 ] .else_ [ _1 * factorial(_1-1) ];
object is a dynamic type (ala scheme/lisp). The difference is that I use a syntax closer to c++. I don't quite like lots of parens and commas.
Hi Joel,
That is pretty neat. What status is Rave in?
Very early alpha prototype. Too much to do to little... ...you know...
Is there any documentation or code examples I can look at?
None yet.
In Rave, is evaluation lazy?
Yes. Are there
lambda expressions in Rave?
Definitely! In Unimperative a function is unevaluated
when not at the beginning of a list. For instance you can write:
Function AddOrSub = (If, (Eq, _1, 0), Add, Sub); Function F1 = (Eval, (AddOrSub, 0), 4, 3); Function F2 = (Eval, (AddOrSub, 1), 4, 3); f1.Evaluate(empty); // evaluates to 7 f1.Evaluate(empty); // evaluates to 1
How would this be done in Rave?
Hmmm. lemme see... object add_or_sub = if_(_1 == 0)[lambda[_1+_2]].else_[lambda[_1-_2]]; object f1 = add_or_sub(0)(4, 3); object f2 = add_or_sub(1)(4, 3); eval(f1); // evaluates to 7 eval(f2); // evaluates to 1 <<< Aside: I'm not quite fond of CamelCase :-) >> If you've seen Phoenix2(http://tinyurl.com/6crgp), Rave is its dynamically-typed counterpart. It's really the same thing. I intend to use it to implement the new AST features of Spirit2 as well as a generic embedded runtime interpreter, say, for parsing c++. Cheers, -- Joel de Guzman http://www.boost-consulting.com http://spirit.sf.net