yes that makes sense. thanks!
On Thu, Sep 27, 2018 at 4:16 AM Mark H Weaver <m...@netris.org> wrote:
> Hi Stefan,
>
> Stefan Israelsson Tampe <stefan.ita...@gmail.com> writes:
>
> > This for guile 2.4 and master,
> >
> >> (eval `(let-syntax ((f (lambda (x) ,#'(+ (pk 'a 1) 2)))) f)
> (current-module))
> >
> > ;;; (#<syntax a> 1)
> >
> > But without eval:
> >> (let-syntax ((f (lambda (x) #'(+ (pk 'a 1) 2)))) f)
> >
> > ;;; (a 1)
>
> I think the mistake is in your code above. In the first case, what you
> want is this:
>
> (eval `(let-syntax ((f (lambda (x) ,'#'(+ (pk 'a 1) 2)))) f)
> (current-module))
>
> Note the addition of a quote (') between the unquote (,) and syntax (#')
> above.
>
> The expression that follows unquote (,) should evaluate to an
> s-expression. In this case, you want it to evaluate to the s-expression
> #'(+ (pk 'a 1) 2), i.e. (syntax (+ (pk 'a 1) 2)), i.e. a list with two
> elements, the first being the symbol 'syntax'. But that's not what
> you're doing above. Instead, you are returning the syntax object
> itself, which is being spliced directly into the code.
>
> Does that make sense?
>
> Mark
>
