4 ms·

With this merged attribute syntax, since each key-value combination is a separate symbol and since symbols are interned, doesn't this mean that all the attribut

• kazinator 3y ago
  Firstly, obviously yes for un-interned. TXR Lisp: This is the TXR Lisp interactive listener of TXR 291. Quit with :quit or Ctrl-D on an empty line. Ctrl-X ? for cheatsheet. I'm confused; is this piano recital Rimsky-Korsakov or Wernicke–Korsakoff? 1> (progn [finalize (gensym "foo-") prinl] nil) nil 2> (sys:gc) #:foo-0012 t 3> (sys:gc) t We make a gensym whose name starts with foo-. We register a GC finalizer for it which is the prinl function (print, with newline). Then when we manually invoke GC, it gets collected; we see the print. Internet symbols cannot be collected, normally, because they are always used: they are registered in their package. TXR Lisp has weak packages, though. A weak package will purge a symbol that is not reachable other than through the package. 1> (make-package "abc" t) ;; t argument here means weak #<package: abc> 2> (progn [finalize (intern "xyz" *1) prinl] nil) nil 3> (sys:gc) abc:xyz t 4> (package-symbols *1) nil 5> Don't know if other Lisp people thunk of this one, but there it is. I don't think I exposed this weak property through the defpackage macro. It's intended for specific scenarios, like reading data in the context of a package.