| > Mathematica It's derived from Wolfram's conception of Macsyma, and it is designed so that all code is made out of numbers, strings, symbols, and arrays (sure, not cons cells). I guess it's nice to know you wouldn't call Mathematica a Lisp, but I didn't say it was strictly in the Lisp family, just a strange variant. (Does this mean you do not consider PicoLisp a Lisp either, since it is not really compilable, as far as I can see? Or is it fine to you because it has a defined evaluator?) Mathematica does have a built-in compiler, but granted it is unclear exactly what subset of the language it is compiling. > There is a variant of that in CL called 'compiler macro'. I am aware, but that certainly does not have the same effect because CL is not required to invoke your compiler macro. This means you cannot rely on compiler macros for control flow manipulations, like what 'and' requires. (I know you said "variant," but they are more of an optimization than what I was talking about.) > (define (foo list) (list list)) As I said, with lexical scoping "this became a bit less of an issue." What I had in mind is that at least any of these kinds of shadowing errors will be entirely local. You won't have the problem that by using 'list' as the name of an argument, if it were dynamically bound in a Lisp-1 it would mess up any function you might call that itself uses 'list'. Lexical scoping at least prevents this spooky action at a distance that you would need a Lisp-2 to prevent under dynamic scoping. |
Thanks!
> but I didn't say it was strictly in the Lisp family, just a strange variant.
Right, that was my point, I don't consider term rewriting systems as Lisp variants, even though they may have numbers and strings as data types. The actual execution engine is too different.
Fexprs had the interesting property that it sees the actual source at runtime (which makes it very different from lazy evaluation or wrapping things in lambdas), which appeals especially to users/implementors of computer algebra systems (see Reduce written in Portable Standard Lisp, which provides Fexprs) or other math software dealing with formulas (like R, which has a feature similar to fexprs).
> Mathematica does have a built-in compiler, but granted it is unclear exactly what subset of the language it is compiling.
From what I read of its very unspecific documentation, I doubt that it does the term rewriting at compile time (like Lisp does macro expansion at compile time) - does it? To me it looks like the compiler targets numeric code and basic control flow...
They probably have better documentation of their language implementation, internally. Or is there an externally available document, which actually describes their implementation?
Mathematica as a rewrite language
https://www3.risc.jku.at/publications/download/risc_342/1996...