Pointers are a central part of the C type system, and because Lisp does not provide them directly, one of the core features of the FLI is a special pointer type that is used to represent C pointers in Lisp. This chapter discusses how to use FLI pointers by examining some of the functions and macros which allow you to create and manipulate them.
A FLI pointer is a FLI object containing a memory address and a type specification. The implication is that the pointer points to an object of the type specified at the memory address, although a pointer can point to a memory location not containing an allocated FLI object, or an object that was allocated with a different type. Pointers can also point to other pointers, and even to functions.
LispWorks Foreign Language Interface User Guide and Reference Manual - 29 Sep 2017