Page:Scheme - An interpreter for extended lambda calculus.djvu/31



The following declarations and macros are present only to make the compiler happy, and to make the version number of the SCHEME implementation available in the global variable.

The function  initializes the system driver. The two 's merely set up version numbers. The top level loop itself is written in SCHEME, and is a  which binds the function   to be a read-eval-print loop. The LISP global variable  is initialized to the closure of the   function for convenience and accessibility to user-defined functions.

When the LISP alarmclock tick occurs, the global register  is set to. , the amount of runtime between ticks, is measured in