%eclent; ]> Primitive types have a single value, these include characters, numbers, and pointers. They are all symbols in the keyword package. :char - Signed 8-bits. A dereferenced :char pointer returns an character. :unsigned-char - Unsigned 8-bits. A dereferenced :unsigned-char pointer returns an character. :byte - Signed 8-bits. A dereferenced :byte pointer returns an integer. :unsigned-byte - Unsigned 8-bits. A dereferenced :unsigned-byte pointer returns an integer. :short - Signed 16-bits. :unsigned-short - Unsigned 16-bits. :int - Signed 32-bits. :unsigned-int - Unsigned 32-bits. :long - Signed 32 or 64 bits, depending upon the platform. :unsigned-long - Unsigned 32 or 64 bits, depending upon the platform. :float - 32-bit floating point. :double - 64-bit floating point. :cstring - A &NULL; terminated string used for passing and returning characters strings with a &C; function. :void - The absence of a value. Used to indicate that a function does not return a value. :pointer-void - Points to a generic object. * - Used to declare a pointer to an object def-constant Binds a symbol to a constant. def-constant name value &key; export name A symbol that will be bound to the value. value An evaluated form that is bound the the name. export When &t;, the name is exported from the current package. The default is &nil; This is a thin wrapper around defconstant. It evaluates at compile-time and optionally exports the symbol from the package. (def-constant pi2 (* 2 pi)) (def-constant exported-pi2 (* 2 pi) :export t) Creates a new special variable.. None. None. def-foreign-type Defines a new foreign type. def-foreign-type name type name A symbol naming the new foreign type. value A form that is not evaluated that defines the new foreign type. Defines a new foreign type. (def-foreign-type my-generic-pointer :pointer-void) (def-foreign-type a-double-float :double-float) (def-foreign-type char-ptr (* :char)) Defines a new foreign type. None. None. null-char-p Tests a character for &NULL; value. null-char-p char char A character or integer. returns A boolean flag indicating if char is a &NULL; value. A predicate testing if a character or integer is &NULL;. This abstracts the difference in implementations where some return a character and some return a integer whence dereferencing a C character pointer. (def-array-pointer ca :unsigned-char) (let ((fs (convert-to-foreign-string "ab"))) (values (null-char-p (deref-array fs 'ca 0)) (null-char-p (deref-array fs 'ca 2)))) => &nil; &t; None. None. None.