<HTML><BODY>Thank you! Now I understand how to do it right. > but then the code it produces (the definition) changes the binding of ID Then why code without (module+ ..) works fine? Even in REPL all is fine. Thu, 03 Apr 2014 09:37:33 -0400 от Ryan Culpepper <ryanc@ccs.neu.edu>: <blockquote style="margin: 10px; padding: 0px 0px 0px 10px; border-left-color: rgb(8, 87, 166); border-left-width: 1px; border-left-style: solid;"> <div> <div class="js-helper js-readmsg-msg"> <style type="text/css"></style> <div> <base href="https://e.mail.ru/" target="_self"> <div id="style_13965328080000000158_BODY">On 04/03/2014 01:26 AM, Roman Klochkov wrote: > #lang racket > (require (for-syntax syntax/id-table)) > > (define-for-syntax table (make-free-id-table)) > > (define-syntax (save-and-define stx) > (syntax-case stx () > [(_ ID) (free-id-table-set! table #'ID 1) #'(define ID 1)])) The problem is that save-and-define puts ID in the table, but then the code it produces (the definition) changes the binding of ID, so when you try to look it up the two versions of ID might not match. The fix is to put the table update after the definition: (define-syntax (save-and-define stx) (syntax-case stx () [(_ ID) #'(begin (define ID 1) (begin-for-syntax (free-id-table-set! table #'ID 1)))])) Or if you want this to work in internal definition contexts: (define-syntax (save-and-define stx) (syntax-case stx () [(_ ID) #'(begin (define ID 1) (define-syntaxes () (begin0 (values) (free-id-table-set! table #'ID 1))))])) Ryan ____________________ Racket Users list: <a href="http://lists.racket-lang.org/users" target="_blank">http://lists.racket-lang.org/users</a> </div> <base href="https://e.mail.ru/" target="_self"> </div> </div> </div> </blockquote> -- Roman Klochkov </BODY></HTML>