That sounds like a black magic. I am almost tempted to ask how it's done. I imagined (gensym) would generate some unique sequence not used so far. Why would this approach not work?
2011/7/31 Jay McCarthy <jay.mccar...@gmail.com>: > Gensym produces symbols that are not eq to any other symbols created any > other way. The bindings library produces symbols from strings, so they aren't > eq to the gensym'd one. > > Jay > > Sent from my iPhone > > On 2011/07/31, at 15:13, J G Cho <g...@fundingmatters.com> wrote: > >> I am a bit puzzled by this error: >> >> >> Exception >> The application raised an exception with the message: >> >> extract-binding/single: 'q10493 not found in '((q10493 . "no")) >> >> >> Context: >> Symbol q10493 was generated by (gensym 'q) and used in >> >> (list (radio-input (symbol->string nom) "yes") >> (radio-input (symbol->string nom) "no"))) >> >> When I try to extract it >> >> (define (extract-single nom) >> (λ (bindings) >> (extract-binding/single nom bindings))) >> >> it complains.... >> >> So I changed to >> (define (extract-single nom) >> (λ (bindings) >> (extract-binding/single (string->symbol (symbol->string nom)) >> bindings))) >> >> And it seems to work but left me scratching my head. >> >> Does anybody care to shed some light on this? >> >> jGc >> >> _________________________________________________ >> For list-related administrative tasks: >> http://lists.racket-lang.org/listinfo/users > _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
