I find some irony in seeing the telltale tropes of conventional LLM writing there

as an adendum, the reason I don't understand the motivation is that the visitor pattern in the way I described it is useful when you have many different operations to perform on your AST. If you have only one operation on tokens - parsing into an AST - I'm not sure why you need dynamic dispatch on a second thing, the first thing being the token type. Maybe the construction is that different operations correspond to different 'grammar rules'?

The visitor pattern is a technique for dynamic dispatch on two values (typically one represents 'which variant of data are we working with' and the other 'which operation are we performing'). You would not generally use that in recursive descent parsing, because when parsing you don't have an AST yet, so 'which variant of data' doesn't make sense, you are just consuming tokens from a stream.

There is an observation that you can use `lambda` inside to delay evaluation of an interpolation, but I think this lambda captures any variables it uses from the context.

V gubhtug vg fbhaqrq fhecevfvat sbe n glcr r gb orunir guvf jnl jura V jebgr zl pbzzrag, ohg abj V ernyvfr gung vg zvtug or pbzzba va nal vzcyrzragngvba bs rdhnyf gung uvqrf vagreany fgngr, n fvzcyr rknzcyr orvat n frg/znc qngnglcr jubfr rdhnyvgl vzcyrzragngvba vtaberf vafregvba beqre ohg jubfr vgrengvba beqre qrcraqf ba vg.

Fb V guvax gur nafjre eribyirf nebhaq gur pbzcbfvgvba ynj. Va bgure jbeqf, vf sznc (sznc frg s) t rdhny gb sznc frg (t . s) sbe nal s naq t?

V guvax guvf ubyqf bayl vs s naq t ner cher (be znlor whfg vs t vf cher?). fb znlor vs lbh vtaber hafnsr bcrengvbaf va unfxryy vg'f gehr? vg'f pregnvayl abg gehr va s#/bpnzy. vzntvar gung s vf sha _ -> 0 naq t vf sha _ -> arkg_vag_sebz_zhgnoyr_pbhagre (). gura sznc frg (t . s) qbrfa'g punatr gur fvmr bs gur frg juvyr sznc (sznc frg s) t cebqhprf n fvatyrgba frg.

That said, I wouldn't compare it to scripting languages. The lack of implicit conversions / traits / ad-hoc polymorphism means it's not that convenient for scripting.

I would disagree with that - I find it easier, more comfortable rather than just faster to read any text in a proportional font because the spacing of characters is, well, proportional to what the form of each letter requires. I think it makes it easier to recognise words. It's true that code has a lot of unusual combinations of characters but still it is mostly ordinary words. A proportional font that makes those unusual combinations of punctutation characters less clear is certainly bad, but there are proportional fonts that don't.