Hi Scott, I think that you're seeing a bug in the current expander's marshaling of information for a compiled module, specifically for the "metadata.rkt" module that supplies `racquel-namespace`.
(The bug was introduced in v6.3 with the set-of-scopes expander. Happily, a re-implementation of the expander doesn't have the bug, but the re-implementation isn't quite ready to replace the current expander.) I'll fix the bug as soon as I can. Meanwhile, if you'd like a workaround: The conflicting "lifted.0" is created in "metadata.rkt" by the contract system's expansion of `~a`. You can work around the problem by changing (~a col-fld) to (format "~a" col-fld) Matthew At Thu, 29 Sep 2016 19:22:37 -0700 (PDT), "'brown131' via Racket Users" wrote: > I was looking through the Racket packages the other day and noticed that > there > are errors in the Racquel package that I maintain. I the error I am seeing is > not very helpful: > > define-values: assignment disallowed; > cannot re-define a constant > constant: lifted.0 > > The problem is that there is no constant anywhere in the code with that name. > I've done some reading and it appears that is may be connected to some > "lifted" syntax. Through a process of elemination by commenting out code, I > narrowed the problem to the block of code below. In particular, if I comment > out the data-class* definition of the stx id and replace it with a simple > class definition, i.e. > "(class object% (super-new))" the error goes away. > > My suspicion is that using the data-class* in the syntax quasi-quote is > somehow lifting the syntax macro to a higher run-level. But how a constant is > re-defined as described in all the error is beyond me. > > (define (gen-data-class con tbl-nm > #:db-system-type (dbsys-type (dbsystem-type con)) > #:generate-joins? (gen-joins? #t) > #:generate-reverse-joins? (gen-rev-joins? #t) > #:schema-name (schema-nm #f) > #:inherits (base-cls 'object%) > #:table-name-normalizer (tbl-nm-norm (lambda (n) > (table-name-normalizer n))) > #:column-name-normalizer (col-nm-norm (lambda (n) > (column-name-normalizer n))) > #:in-name-normalizer (join-nm-norm (lambda (n (c > 'one-to-many)) > > (join-name-normalizer n c))) > #:table-name-externalizer (tbl-nm-extern (lambda (n) > (begin n))) > #:print? (prnt? #f) > . rest) > (let* ([schema (load-schema con schema-nm tbl-nm #:reverse-join? > gen-rev-joins? > #:db-system-type dbsys-type)] > [cls-nm (string->symbol (tbl-nm-norm tbl-nm))] > [pkey (find-primary-key-fields schema col-nm-norm)] > [jns (if (or gen-joins? gen-rev-joins?) > (get-schema-joins con schema-nm schema dbsys-type > tbl-nm-norm join-nm-norm > col-nm-norm) null)] > [auto-key (get-autoincrement-key schema dbsys-type)] > [stx #`(let ([#,cls-nm > (data-class* #,base-cls (data-class<%>) > (table-name #,tbl-nm #,(tbl-nm-extern > tbl-nm)) > #,(append '(column) (get-schema-columns > schema col-nm-norm)) > (primary-key '#,pkey #:autoincrement > #,auto-key) > #,(if (and gen-joins? (list? jns) (> > (length jns) 0)) > (append '(join) jns) '(begin #f)) > (super-new) > #,@rest) > ]) > (get-class-metadata-object #,cls-nm) > #,cls-nm)]) > (if prnt? (syntax->datum stx) (eval-syntax stx racquel-namespace)))) > > Here is the syntax definition for the data-class*: > > ;;; Define a data class with interfaces. > (define-syntax (data-class* stx) > (syntax-parse stx > [(_ base-cls:id (i-face:id ...) elem:data-class-element ...) > (with-syntax ([cls-id (generate-temporary #'class-id-)] > [m-data (generate-temporary #'metadata-)] > [ctxt ctxt-id] > [set-auto-pkey! set-auto-pkey!-id] > [set-pkey! set-pkey!-id] > [set-tbl-nm-m-data! set-tbl-nm-m-data!-id] > [jn-fld jn-fld-id] > [jn-cls jn-cls-id] > [con con-id] > [dbsys-type dbsys-type-id]) > #'(let* ([ctxt null] > [m-data (new data-class-metadata%)] > [set-tbl-nm-m-data! (λ (tbl-nm extern-nm) (set-field! > table-name m-data tbl-nm) > (set-field! external-name m-data > extern-nm))] > [set-auto-pkey! (λ (pkey flag) (set-field! primary-key m-data > pkey) > (when flag (set-field! autoincrement-key > m-data flag)))] > [set-pkey! (λ (pkey) (set-field! primary-key m-data pkey))]) > (unless (hash-has-key? *data-class-metadata* 'cls-id) > elem.meta-expr ... > (set-field! columns m-data (sort (append elem.col-defs ...) > string<? > #:key (lambda (k) (symbol->string > (first k))))) > (set-field! joins m-data (append elem.jn-defs ...)) > (hash-set! *data-class-metadata* 'cls-id m-data)) > (define-member-name cls-id (get-field class-id-key m-data)) > (define-member-name data-object-state (get-field state-key m-data)) > (class* base-cls (data-class<%> i-face ...) > elem.cls-expr ... > (field [cls-id #f] > [data-object-state 'new]) > (inspect #f) > (define/public (set-data-join! con jn-fld jn-cls) > (let* ([dbsys-type (dbsystem-type con)] > [rows (append elem.jn-rows ...)]) > (map (lambda (r) (let ([obj (new jn-cls)]) > (map (lambda (f v) (dynamic-set-field! f > obj v)) > (get-column-ids jn-cls) > (vector->list > r)) > (define-member-name data-object-state > (get-class-metadata state-key jn-cls)) > (set-field! data-object-state obj 'loaded) > obj)) rows))) > (define/private (base-data-class cls) > (let-values ([(cls-nm fld-cnt fld-nms fld-acc fld-mut sup-cls > skpd?) (class-info cls)]) > (if (data-class? cls) (if sup-cls (base-data-class sup-cls) > cls) cls))) > (unless (get-field class (hash-ref *data-class-metadata* > 'cls-id)) > (set-field! class (hash-ref *data-class-metadata* 'cls-id) > (base-data-class this%))))))])) > > Source complete can be found here > https://github.com/brown131/racquel/blob/master/main.rkt > > It's been a while since I've worked with this, and am admittedly a little > rusty on Racket syntax manipulation. Any help would be appreciated. Thanks. > > -Scott > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to racket-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Racket Users" group. 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