fli:with-dynamic-foreign-objects

(fli:with-dynamic-foreign-objects ((var type &key nelems initial-element initial-contents fill)*) form*)

Evaluates forms with each var bound to a foreign object of the FLI type type (unevaluated; the keys as fli:allocate-foreign-object takes them), and frees every one on every exit, answering the last form's values. LispWorks allocates them on the stack; here they are heap memory, so a pointer kept past the form dangles all the same. Part of the macOS-only fli package, beside objc -- the interpreter (java -jar, or the rontolisp native binary), a compiled .class / .jar and a --native executable for macOS on Apple silicon, never a .wasm. See the macOS GUI guide.

MY-APP> (fli:with-dynamic-foreign-objects ((result-value :int))
          (invoke (invoke "NSScanner" "scannerWithString:" "42 apples") "scanInt:" result-value)
          (fli:dereference result-value))
42