fli:size-of

(fli:size-of type-name)

The size in bytes of an FLI type, by the C layout rule: :int is 4, :pointer 8, (:c-array :int 4) 16, and the Foundation structures are LispWorks' own, cocoa:ns-rect 32 and the other three 16. 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.

CL-USER> (mapcar #'fli:size-of '(:char :int :double cocoa:ns-rect))
(1 4 8 32)