1.1 A simple example of how to interface a foreign function
1.1.3 Calling foreign code
Calling the foreign code is the simplest part of using the FLI. The interface to the C function, defined usingdefine-foreign-function, is called like any other Lisp function. In our example, thefarenheit-to-celsius function takes the temperature in Farenheit as its only argument, and returns the temperature in Celsius.