On Tuesday 24 February 2009 21:51:45 Andre van Tonder wrote: > On Tue, 24 Feb 2009, Christian Sloma wrote: > > On Tuesday 24 February 2009 21:01:58 Andre van Tonder wrote: > >> On Tue, 24 Feb 2009, Christian Sloma wrote: > >>>> Where is the burden on macro-free programs? (This is not meant to be > >>>> argumentative---I am genuinely trying to understand this criticism). > >>> > >>> Just one example: R6RS disallows the mixing of expression and > >>> definitions in libraries. > >> > >> This restriction has nothing to do with macros, though. Expressions > >> could have been allowed easily, as you will see if you consider that > >> even in R6RS you can get the effect of an interleaved expression by > >> simply making it the RHS of a dummy definition. > > > > Note that it *has* to be inside a define, as the define marks the body to > > be delayed until all off the other definitions are evaluated. > > The expansion process for <library body> could have been declared to be > exactly the same as the expansion process for <top-level body>, which > allows interleaved expressions that are not inside a define. The fact that > it wasn't so defined was just an arbitrary design choice.
It could have been and it should have (IMHO) been, but it was not :) which is exactly what we are talking about here: the ability to reference macros before they are defined negatively impacts code that does not even use macros. _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
