lec19.scm

### Begin ###

(define (f x) (print x) (print x) (print x))

(if #t (print 3) (print 3))
 
(if #t ((print 3) (print 3)) (print 4))
 
(if #t (begin (print 5) (print 6)) (print 7))
 


### List Equivalence ###
 
(define a '(1 2 3))
 
(define b '(1 2 3))

 
(define c a) 
 
 
(eq? a b)
(eq? a c)
(equal? a b)
(equal? a c)
  
 
### List Manipulation ###
 
 (length '(1 2 3 4 5))
 (length '(1 (2)))
  
 (append '(1 2 3) 4)
 (append '(1) '(2))
  
  
 (map abs '(-1 -1 -1 0 0 0)) 
 (map (lambda (x) (+ 1 x)) '( 1 2 3 4))
  
 
 (filter odd? '(1 2 3 4 5))
  
 (reduce * '(1 2 3 4 5))
  
  
  ### Eval ###
  
  
  '(print 1)
  (eval '(print 1))
   
  (eval '(if #t (print 5) (print 6)))
   
  
   
  ### Quasiquote ###
   
  (define a 5)
  (define b 10)
   
   
  '(a b)
   `(a b)
   `(a ,b) 
   
   `(a ,(* b 100))
   
   
   
   ### Exponents with Lists ###
   
   
   (define (exp base power)
      (if (= power 0) 1
        (list '* (exp base (- power 1)) base)))