On 11 Sep 2009, at 5:00 pm, David Van Horn wrote: > John Cowan wrote: >> David Van Horn scripsit: >>> What does "low-level hygienic macros" mean? >> Alex Shinn's discussion of the matter at >> http://www.mail-archive.com/[email protected]/msg08779.html >> is very >> illuminating, if you discount his obvious prejudice against syntax- >> case. > > So "low-level" vs. "high-level" boils down to the disjointness of > pairs, symbols, etc. versus syntax objects?
Not really; IMHO, high-level macros mean having a pattern-matching syntax for disassembling the input forms, while low-level macros mean passing it to an arbitrary Scheme function (whether as pairs/symbols or as syntax objects) - that function may then invoke some general pattern-matching facility on it if it chooses to, but it *could* take it to bits with car and cdr. So high-level can be a library built on top of low-level. > If so, I believe R6RS does not specify its "level", and if I recall > correctly, Andre van Tonder had a "low-level" R6RS expander in which > syntax objects were not distinct. (I keep using scare quotes > because I think this terminology is awful and should be abandoned). Yeah, it is unfortunate wording... > > David > ABS -- Alaric Snell-Pym Work: http://www.snell-systems.co.uk/ Play: http://www.snell-pym.org.uk/alaric/ Blog: http://www.snell-pym.org.uk/archives/author/alaric/ _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
