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Andre van Tonder <andre@xxxxxxxxxxxxxxxxx> writes: > The issues section states: > > "Macros that expand into the implicit-naming layer might have unexpected > behavior, as field names that are distinct as identifiers may not be distinct > as symbols, which is how they're used." > ^^^^^^^^^^ > > Is the concept of distinctness defined with respect to symbolic equivalence? Not so far as I know. > It is not obvious to me that this should be the case. > In the context of syntax-case, my first thought was that perhaps > free-identifier=? might be a more appropriate predicate for > distinctness, but then the following occurred to me: > > (define-syntax foo > (syntax-rules () > ((_ f) > (define-record-type p > (fields (mutable x) ; - would make a secret p-x > (mutable f)))))) ; - would make a toplevel p-x > ; when called as below > > (foo x) > > In implementations of syntax-case that treat defines on > macro-generated identifiers as establishing "secret" bindings > (such as Chez and PLT), the p-x bindings for the two fields would > be distinct, and not interfere, even though they are > free-identifier=? So the example would probably work. That would depend on the way the macro defining the implicit variant of DEFINE-RECORD-TYPE is written, right? In particular, I think the ones that I wrote decompose the names into strings and then back, so I think any distinctness might get lost on the way. -- Cheers =8-} Mike Friede, Völkerverständigung und überhaupt blabla