Ch 4 Flashcards
In Scheme, the primitive (char? “%\A”) will return…
f
(member ‘2 ‘(3 4 2 1)) will return…
(2 1)
(caddr ‘(2 4 6 8 10)) will return…
6
The most efficient way, in terms of the execution time, to check whether a list L is empty is by…
(NULL? L)
Which of the following forms is an unnamed procedure?
(+ z 3)
((lambda (z) (+z 3)) 4)
(define foo (lambda (z) (+ z 3)))
(define bar 25)
None of them
((lambda (z) (+ z 3)) 4)
Eager evaluation evaluates…
all parameters of a function first.
Lazy evaluation evaluates…
a parameter of a function only if it is necessary.
In “imperative” programming languages, different orders of evaluations (eager or lazy)…
may produce different results.
In “functional” programming languages, different orders of evaluations (eager or lazy)…
never produce different results.
Each let-form in Scheme can be converted into…
an unnamed procedure.
Assume that you have (define x ‘(5)) and (define y ‘(8 9)). What operation will return the list (5 8 9)?
(append x y)
Which of the followings is NOT a Scheme pair?
’()
What is the return value of the following form?
(filter (lambda (x) (> x 20)) ‘(10 30 15 10 80))
(30 80)
A deep-filter can be used in the situation where the list…
contains sublists.
What is the return value of the following form?
(map (lambda (x) (+ x 10)) ‘(10 30 15))
(20 40 25)
In Scheme, an empty list is…
not a pair.
What mechanism cannot be used for passing a value into a Scheme procedure?
Call-by-alias
How is a procedure name (operator) passed into a procedure?
Call-by-name
If you want to return multiple values from a Scheme procedure, which of these methods is invalid?
Use multiple return-statements.
Normally, a recursive procedure can be written following these steps: Define the size-n problem, find the solution for the base case or the stopping condition, and then find…
the solution of the size-n problem based on the hypothetical solution of the size-(n-1) problem.
In the Functional Paradigm, what are functions treated as?
First-class objects. They can be placed anywhere where a value is expected.
From what programming language is Scheme derived?
LISP
What order to eager and lazy evaluation, evaluate parameters?
Eager - innermost first
Lazy - outermost first
What are the three parts of defining a procedure in Scheme?
Define, Name and parameters, Argument
(define (<name><parameters>) <body>)</parameters></name>
How should procedures and variables be named in Scheme?
With lower case words separated by dashes.
What are the basic data types in Scheme?
Number - includes integers and floats
String - uses “ “
Symbol - uses a single ‘
List - can be a list of elements of any type ‘(2 5 5 Hi Jim (5 9) “Hello”)
What is the difference between “James” and ‘James ?
“James” is a string.
‘James is a symbol.
What C or C++ structure is closest to resembling a Scheme Symbol?
enum
Lists in Scheme are just…
parameterized expressions.
In Scheme, the primitive (char? #\A) will return…
t
must be #, not %
must not have “ “
What does (char=? #\A #\a) return?
f
characters must be identical for (char=?
What does (char=? #\A #\A) return?
t
because characters are identical
What must we always have in a Functional language?
A return value.
