Computer Science- Primitives Flashcards
(20 cards)
1
Q
(max a b)
A
accepts numeric inputs a, b and returns the greater of the two
2
Q
(abs a)
A
accepts numeric input a and returns the absolute value
3
Q
(quotient a b)
A
returns whole number part of a/b
4
Q
(remainder a b)
A
returns remainder a b
5
Q
(time (fxn call))
A
- evaluates (fxn call), then returns the time in ms required to evaluate (fxn call)
- must switch to INTERMEDIATE LANGUAGE
6
Q
(begin
…)
A
executes tasks in order
7
Q
(display a)
A
- displays contents of a
- ex (define a 42)
(display a) –> 42
8
Q
(display ‘a)
A
a
9
Q
(display “text”)
A
text
10
Q
(newline) or “\n”
A
inserts a carriage return or newline
11
Q
(null? L)
A
- # t if L is an empty set [’( )], #f otherwise
- language must be FULL SWINDLE
12
Q
(list? L)
A
returns #t if L is a list, #f otherwise
13
Q
(length L)
A
of cells on top in a con cell diagram
14
Q
(equal? L)
A
- # t if a and b are equal, #f otherwise
- unlike (= a b), this can compare LISTS
15
Q
(cons a b)
A
- returns a list with a as its CAR part and b as its CDR part
- b should be a list
- (cons 1 2 3) –> error
- (cons 1 ‘(2 3)) –> ‘(1 2 3)
- (cons ‘(1) ‘(2 3)) –> ((1) 2 3)
- essential to maintaining list structure in handling sublists
16
Q
(append a b)
A
- combines list a and b into a single list
- both have to be a list
- (append 1 2 3) –> error
- (append 1 ‘(2 3)) –> error
- (append ‘(1) ‘(2 3)) –> (1 2 3)
17
Q
(list …)
A
- returns a list comprised of args 1 through n in order
- (list 1 2 3) –> ‘(1 2 3)
- (list 1 ‘(2 3)) –> ‘(1 (2 3))
- (list ‘(1) ‘(2 3)) –> ‘((1) (2 3))
18
Q
(number? a)
A
t if a is numeric, #f otherwise
19
Q
(cadr L)
A
(car (cdr L))
20
Q
(random n)
A
returns a random integer on interval [0, n) or [o, n-1]
