CSC151.02 2003F, Class 12: Conditionals

Admin:
* Cool math talk tomorrow at 4:30.  Snacks at 4:15.
* Friday is "Talk like a pirate day"
* No reading for Thursday!
* Rearrangement of syllabus
* Stuff due

Overview:
* Lab
* Refelection
* Style and conditionals

REFLECTION

* A useful way to do multiple comparisons
	(<= 0 grade 100)

SOME STYLISTIC ISSUES

* Be careful about returning #t or #f from a conditional.  Consider
	(if SOME-TEST #t #f) => SOME-TEST
	(if (<= 0 grade 100) #t #f) => (<= 0 grade 100)

	(if SOME-TEST #f #t) => (not SOME-TEST)

	(define in-range
	  (lambda (a b c)
	    (if (<= a b c)
	        #t
                (if (>= a b c)
	            #t
	            #f))))

	(define in-range
	  (lambda (a b c)
	    (if (<= a b c)
	        #t
                (>= a b c))))

	(define in-range
	  (lambda (a b c)
	    (or (<= a b c) (>= a b c))))

Whenever true or false is stated explicitly, you can probably get rid of it.

	(if TEST1 #t TEST2) => (or TEST1 TEST2)
	(if TEST1 #f TEST2) => (and TEST1 TEST2)