PPT Slide

1. “currying” -- use lambda expressions to create functions with fewer arguments

( defun incr ( x L )

( mapcar # '(lambda ( y ) (+ x y ) ) L ) )

( incr 2 '( 4 1 3 ) ) returns ( 6 3 5 )

2. Use of auxiliary functions to make programs

more readable and sometimes more efficient.

3. “tail recursion” -- recursion where all the work

is done on the way down, returns just pass control

back up.

( defun tr-fact ( n ) ( f-aux n 1 ) )

( defun f-aux ( n res )

( if ( zerop n ) res

( f-aux ( 1- n ) ( * n res ) ) ) )