Alaric Snell-Pym scripsit: > Ah-hah. So having feature groups separate like that is a way to allow > programmers to omit to declare their requirements in order to create > code that may break unexpectedly? :-)
Pretty much. Look how things work today: $ chibi-scheme > (define x (make-rectangular 1 2)) ERROR: undefined variable: make-rectangular WARNING: reference to undefined variable: make-rectangular > Okay, switch to a different Scheme. I'm not proposing to change that, just to add a small amount of introspection so that you can see this Scheme doesn't support complex numbers. That's all feature groups are, really. Having to import complex numbers from a module, when we know that most Schemes either have them built in or can't do them at all, is overkill for a small Scheme. ObData: I tried the above expression on my usual list of Schemes, and came up with this: Returns 1+2i: PLT, MIT, Gambit, Chicken with numbers egg, scsh/Scheme48, Kawa, Chez, Ikarus, Larceny, Scheme 7. Returns 1.0+2.0i: Gauche, SISC, SCM, VScheme. Error: Chicken, Bigloo, Scheme 9, SScheme, SXM, Chibi. -- John Cowan [email protected] http://ccil.org/~cowan The present impossibility of giving a scientific explanation is no proof that there is no scientific explanation. The unexplained is not to be identified with the unexplainable, and the strange and extraordinary nature of a fact is not a justification for attributing it to powers above nature. --The Catholic Encyclopedia, s.v. "telepathy" (1913) _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
