




 
The FLI provides the :boolean type to interface a Lisp boolean value (
t
 or 
nil
) with a C 
int
 (0 corresponding to 
nil
, and any other value corresponding to 
t)
. The 
:boolean
 type can be modified to make it correspond with other C types. For example, 
(:boolean :byte
) would associate a Lisp boolean with a C 
byte
, and 
(:boolean :long)
 would associate a Lisp boolean with a C 
long
.