R. Kent Dybvig scripsit: > Actually, the point is that they permit one to deal sensibly with lexical > scoping at the source level. This not only simplifies the coding of many > macros but also allows the definition of others that cannot be written > with defmacro. For example, one can use syntax-rules and syntax-case to > write macros that perform arbitrary code motion (e.g., define-integrable) > without breaking lexical scope.
I'm no expert on the subject and you are, but I don't see how there can be anything that define-macro cannot do, since it applies a Turing-complete language to arbitrarily large parts of the program. > In fact, syntax-case is strictly more expressive than the old-style Lisp > macros represented by defmacro. The lisp-transformer on page 54 of the > library document shows how syntax-case can be used (trivially) to write > old-style Lisp macros. Defmacro itself is easily defined using > lisp-transformer. It sounds like they are equivalent in power, then. -- In politics, obedience and support John Cowan <[EMAIL PROTECTED]> are the same thing. --Hannah Arendt http://www.ccil.org/~cowan _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
