A string naming an Objective-C class or a pointer to an Objective-C foreign object.
A string naming the method to invoke or a list as specified below.
Arguments to the method.
The function invoke is used to call Objective-C instance and class methods. If class-or-object-pointer is a string, then it must name an Objective-C class and the class method named method in that class is called. Otherwise class-or-object-pointer should be a foreign pointer to an Objective-C object or class and the appropriate instance or class method named method is invoked.
If method is a string then it should be a concatenation of the message name and its argument names, including the colons, for example "setWidth:height:".
Otherwise method must be a list in one of two forms:
method-name must be a string, as described when method is a string above. arg-types must be a list of FLI argument types, each one matching the corresponding argument to the method. result-type must be the FLI result type of the method, which defaults to :void if omitted. This is primarily intended for invoking methods using vector types, which are not compatible with the Objective-C Runtime type encoding API. See Invoking a method that uses vector types.
Each argument in args is converted to an appropriate FLI Objective-C value and is passed in order to the method. This conversion is done based on the signature of the method as follows:
If the argument is a vector of four elements of the form #(x y width height), the x, y, width and height are used to form the rectangle. Otherwise it is assumed to be a foreign pointer to a ns-rect nd is copied.
If the argument is a vector of two elements of the form #(width height), the width and height are used to form the size. Otherwise it is assumed to be a foreign pointer to a ns-size and is copied.
If the argument is a vector of two elements of the form #(x y), the x and y are used to form the point. Otherwise it is assumed to be a foreign pointer to a ns-point and is copied.
If the argument is a cons of the form (location . length), the location and length are used to form the range. Otherwise it is assumed to be a foreign pointer to a ns-range object and is copied.
The argument should be a foreign pointer to the appropriate struct object and is copied.
If the argument is nil then NO is passed, if the argument is t then YES is passed. Otherwise the argument must be an integer (due to a limitation in the Objective-C type system, this case cannot be distinguished from the signed char type).
If the argument is a string then it is converted to a newly allocated Objective-C NSString object which is released when the function returns.
If the argument is a vector then it is recursively converted to a newly allocated Objective-C NSArray object which is released when the function returns.
If the argument is nil then a null pointer is passed.
Otherwise the argument should be a foreign pointer to an Objective-C object of the appropriate class.
The argument is coerced to an Objective-C class pointer as if by coerce-to-objc-class. In particular, this allows strings to be passed as class arguments.
If the argument is a string then it is converted to a newly allocated foreign string which is freed when the function returns.
Otherwise the argument should be a foreign pointer.
The argument should be a foreign pointer to a struct whose type is defined by define-objc-struct with :foreign-name structname.
other integer and pointer types
All other integer and pointer types are converted using the normal FLI rules.
When the method returns, its value is converted according to its type:
A vector of four elements of the form #(x y width height) is created containing the rectangle.
A vector of two elements of the form #(width height) is created containing the size.
A vector of two elements of the form #(x y) is created containing the point.
A cons of the form (location . length) is created containing the range.
Other structures cannot be returned by value using invoke. See invoke-into for how to handle these types.
If the value is NO then 0 is returned, otherwise 1 is returned. See also invoke-bool.
An object of type objc-object-pointer is returned.
The value is converted to a string and returned.
other integer and pointer types
All other integer and pointer types are converted using the normal FLI rules.
LispWorks Objective-C and Cocoa Interface User Guide and Reference Manual - 21 Mar 2017