objc:define-objc-method

(objc:define-objc-method (name result-type [result-style]) ((object-var class-name [pointer-var]) (arg-var arg-type [arg-style])*) form*)

Defines the instance method name (the selector with its colons) of a class objc:define-objc-class defined; forms are its body. object-var is bound to the receiver's objc:standard-objc-object (or its pointer when it has none), pointer-var to its pointer. Arguments and the result are converted by their declared FLI types, of any shape: integers, :float / :double, objc:objc-bool / :boolean as t / nil, objc:objc-object-pointer, objc:sel, objc:objc-class, a pointer as a foreign pointer to its declared type, and a structure as the Lisp value objc:invoke uses for it (answered, a foreign pointer to one is copied). An object argument's arg-style string converts an NSString to a string, array an NSArray to a vector, (array style) its elements too; :foreign passes the raw value. A string or a vector answered as an object becomes an NSString / NSArray. A non-keyword result-style names a variable bound to a foreign object of the result type, which the body fills (fli:foreign-slot-value, cocoa:set-ns-rect*) and which is answered. Inside the body (objc:current-super) sends to the superclass. An error in the body is printed and the method answers its zero value. Part of the macOS-only objc package -- 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. The definition needs no runtime: the Objective-C side is made when the runtime is opened (objc:ensure-objc-initialized, or the first send). See the macOS GUI guide.

MY-APP> (define-objc-class my-object ()
          ((slot1 :initarg :slot1 :initform nil))
          (:objc-class-name "MyObject"))
MY-OBJECT
MY-APP> (define-objc-method ("areaOfWidth:height:" (:unsigned :int))
            ((self my-object)
             (width (:unsigned :int))
             (height (:unsigned :int)))
          (* width height))
"areaOfWidth:height:"
MY-APP> (invoke (alloc-init-object "MyObject") "areaOfWidth:height:" 6 7)
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