On Dec 19, 2014, at 11:39 PM, Marco Maggi <marco.maggi-i...@poste.it> wrote:
> Wette, Matthew R (3441) wrote: > >> Sorry to bug, I can't figure out why "sval" in the second evaluation >> of "sect" is bound to the "sval" from the first evaluation of "sect". >> Anyone understand? This is guile 2.0.11. -- Matt > > (define-syntax sect > (syntax-rules () > ((sect <name> <expr> ...) > (let ((sval '((name . <name>) (title . #f)))) > (format #t "new sect: ~a\n" (quote <name>)) > (format #t " sval= ~a\n\n" sval) > (assq-set! sval 'title "ABC") > (values))))) > > The problem is that ASSQ-SET! mutates the result of the literal > expression: > > '((name . <name>) (title . #f)) > > > To solve the problem you have to replace: > > '((name . <name>) (title . #f)) > > with: > > (list (cons 'name <name>) (cons 'title #f)) > OK. Thanks. I'm guessing list-copy would be another option: (sval (list-copy '((a . 1) (b . 2))) Matt
