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. That is, the following interaction works perfectly fine:
> (define-syntax (foo stx) #'7) > (+ foo 2) 9 > foo 7 2. Then the section should explain that it is the use of syntax-rule/syntax-rules/syntax-case/syntax-parse that forces stx to be in a certain shape. If foo is not defined with any of these features, the identifier alone triggers an expansion. So, when define-syntax demands the use of syntax-parse (or friends) but you also want to use this identifier with a related meaning in an identifier position, you should use syntax-id-rules. Does this make sense? -- Matthias On Dec 5, 2012, at 7:23 AM, Matthew Flatt wrote: > I'd like to improve the documentation, but I can't tell which part > you're talking about. (The only place where I can find "identifier > macros" is in the Guide, but that's about `syntax-rules' versus > `syntax-id-rules'.) Can you point to the part that you're reading and > the specific text that seems misleading? > > At Tue, 4 Dec 2012 17:16:17 -0500, Carl Eastlund wrote: >> I'm confused about so-called "identifier macros". I had thought that >> ordinary transformers bound to functions could only transform >> application-position references to themselves, and that a "set! >> transformer" was required to transform bare references and set! >> references. Turns out I was wrong, set! transformers are in fact only >> required to transform set! references. So why are they listed under the >> documentation for "identifier macros" and why does that documentation imply >> that normal transformers can't handle bare references? >> >> Carl Eastlund >> _________________________ >> Racket Developers list: >> http://lists.racket-lang.org/dev > _________________________ > Racket Developers list: > http://lists.racket-lang.org/dev
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