At Wed, 5 Dec 2012 14:25:29 -0500, Carl Eastlund wrote: > On looking back, my confusion was not entirely due to the documentation, > but partly from my own expectations coming in to it. If I just look up > "identifier macro", trying to figure out how to write one, I get a link to > section 16.1.5.
Ah, that makes sense. Thanks! > This does not directly state the context involving > syntax-rules; it instead describes an identifier macro simply as "...works > in any expression". The documentation then goes on to present > syntax-id-rules as a mechanism for identifier macros, presenting set! > transformation as well. So while it doesn't explicitly state that set! > transformers and identifier macros are the same thing, it does appear to > imply it and doesn't clarify the matter. If we're going to use "identifier > macro" as an indexed technical term, we should probably have a more precise > discussion of it in the reference manual as well that spells out how these > things work. I know I wasn't the only one surprised to find out that > ordinary define-syntax & syntax-case / syntax-parse macros can expand (what > most people would call) identifier macros. The only way I can figure this > out in the documentation is from a very close reading of the low-level > expansion model, which is not written terribly plainly to begin with. > > --Carl > > Carl Eastlund > > On Wed, Dec 5, 2012 at 2:12 PM, Matthew Flatt <mfl...@cs.utah.edu> wrote: > > > At Wed, 5 Dec 2012 09:41:37 -0500, Matthias Felleisen wrote: > > > > > > I think two additions/refinements would be good here: > > > > > > 1. The section on identifier macros in the Guide (16.1.5) should mention > > that > > > define-syntax introduces short-hands for identifiers, period. > > > > I think "a `define-syntax' that binds to a procedure of one argument" > > is what you mean --- but section 16.1 is about `syntax-rules' and > > `syntax-id-rules', not procedures as transformers. > > > > Improving the start of 16.2 along these lines makes sense, along with a > > better connection to 16.1. Or maybe you're suggesting a different > > organization than the current 16.1--16.2 split? > > > > I'm still unclear on the specific text that confused Carl, though. Was > > it 16.1? > > > > > > _________________________ Racket Developers list: http://lists.racket-lang.org/dev
