FLI types are defined for integers of particular sizes. These are equivalent to the types defined by ISO C99. For example, Lisp :uint8
is ISO C99 uint8_t.
The types have these meanings:
8-bit unsigned integer
16-bit unsigned integer
32-bit unsigned integer
64-bit unsigned integer
The largest type of unsigned integer available
An unsigned integer the same size as a pointer
LispWorks Foreign Language Interface User Guide and Reference Manual - 16 Feb 2015