This would be fine by me! On Fri, May 31, 2019 at 2:07 PM Matthew Butterick <m...@mbtype.com> wrote:
> Maybe the whole syntax of `define-meta` is idiosyncratic and we could add > (without breaking any compatibility): > > ◊(meta-set! 'key (* 6 7)) > > Since `metas` is a hash, `meta-set!` would echo `hash-set!`. And as with > `hash-set!`, the key and value would be expressions. > > > > On May 29, 2019, at 3:28 PM, Matthew Butterick <m...@mbtype.com> wrote: > > > > tl;dr > > > > 1) Would it be useful to allow meta values to be expressions, not merely > datums? > > 2) Is anyone using identifiers or lists as meta values? Mostly my > impression is that they're usually strings, numbers, or booleans (whose > meaning wouldn't change with this upgrade). > > > > > > > > I was thinking that it would be easy to make meta values expressions > rather than datums, so that something like this: > > > > ◊(define-meta foo (* 6 7)) > > > > Means that the `foo` meta is 42. > > > > You could, in theory, run anything you wanted there: > > > > ◊(define meta bar (let () (local-require every/module) > (do-a-zillion-things)) > > > > This isn't quite backward-compatible. Datums that are self-quoting, like > strings, numbers, and booleans, are the same under either system. > > > > But things that look like evaluatable expressions — especially naked > identifiers and lists — would be different. > > > > ◊(define-meta id bar) > > > > Today, this results in a meta value of `'bar`. But if meta values are > treated as expressions, it would just be `bar`, and trigger an > unbound-identifier error. > > > > Or again consider: > > > > ◊(define-meta foo (* 6 7)) > > > > Today, this results in a value of `'(* 6 7)`, but it would not under the > new system. > > > > I can't really tell, however, whether the theoretical benefits outweigh > the theoretical costs. > > > > -- > You received this message because you are subscribed to the Google Groups > "Pollen" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to pollenpub+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/pollenpub/E38816E6-5D29-4916-8EC3-40F14B3188E0%40mbtype.com > . > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Pollen" group. To unsubscribe from this group and stop receiving emails from it, send an email to pollenpub+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/pollenpub/CAOdqJSjmDgW5LN3Hb8e%3DCXChnt8doGpzcEQOhdaFQ58HryTWvQ%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
