diff --git a/examples/ffi/cffi.lsp b/examples/ffi/cffi.lsp new file mode 100644 index 00000000..e6924d15 --- /dev/null +++ b/examples/ffi/cffi.lsp @@ -0,0 +1,27 @@ +#| +Build and load this module with (compile-file "cffi.lsp" :load t) +|# +;; +;; This toplevel statement notifies the compiler that we will +;; need this shared library at runtime. We do not need this +;; statement in windows. +;; +#-(or ming32 windows) +(cffi:load-foreign-library #+darwin "/usr/lib/libm.dylib" + #-darwin "/usr/lib/libm.so") +;; +;; With this other statement, we import the C function sin(), +;; which operates on IEEE doubles. +;; +(cffi:defcfun ("sin" c-sin) :double :double) +;; +;; We now use this function and compare with the lisp version. +;; +(format t "~%Lisp sin:~t~d~%C sin:~t~d~%Difference:~t~d" + (sin 1.0d0) (c-sin 1.0d0) (- (sin 1.0d0) (c-sin 1.0d0))) +;; +;; The following also works: no declaration! +;; +(let ((c-cos (cffi:foreign-funcall "cos" :double 1.0d0 :double))) + (format t "~%Lisp cos:~t~d~%C cos:~t~d~%Difference:~t~d" + (sin 1.0d0) c-sin (- (sin 1.0d0) c-sin)))