Functional Languages (L14)

Question 1

The design of imperative languages is based directly on which architecture model?

Answer 1

Von Neumann
architecture.

Question 2

Does the Von Neumann architecture prioritize suitability for software development, or efficiency?

Answer 2

Efficiency.

Question 3

Define the mathematical function.

Answer 3

it is a mapping of members of one (domain) set, to another (range) set.

Question 4

C, Python, and Java functions are better described as?

Answer 4

Procedures.

Question 5

What difference is there between procedures and true functions?

Answer 5

Procedures produce side effects (not pure mappings).

Question 6

Does the modification of a global variable within a function count as a side effect?

Answer 6

Yes.

Question 7

What term is used to refer to the consistency of a function’s output?

Answer 7

Referential integrity.

Question 8

Do procedures in C, Python or Java have referential integrity?

Answer 8

They might - not neccesarilly, as is the case for pure functions.

Question 9

Do side effects affect the evaluation order of statements?

Answer 9

Yes - the elimination of side effects generally reduce the importance of evaluation order.

Question 10

Are functional languages used in industry?

Answer 10

Not as much as imperative languages.

Question 11

Are functional languages used in research?

Answer 11

Mostly, yes.

Question 12

Do imperative or functional languages have greater correctness?

Answer 12

Functional, and thus functional languages are more reliable.

Question 13

In what way does correctness impact concurrency?

Answer 13

Correct functions do no manipulate global state, and thus they may be executed concurrently.

Question 14

What’s a higher-order function?

Answer 14

A function that takes functions as parameters and/or yields a function as its result.

Question 15

What’s a functional form?

Answer 15

Same as a higher order function.

Question 16

“First class functions” refers to what type of functions?

Answer 16

Functions that can be used in the same way as any basic data type.

Question 17

Why don’t C’s function pointers count as first class functions?

Answer 17

Because C requires explicit prototyping when passing functions as parameters, and is much more fragile when using functions as types.

Question 18

Does Python support first class functions?

Answer 18

Unlike C, Python does support first class functions.

Question 19

Function composition is a functional form that does what?

Answer 19

That yields a function whose value is the first parameter (function) applied to the application of the second.

Question 20

Does C support function composition?

Answer 20

No.

Question 21

Do functional languages rely on iteration or recursion?

Answer 21

Recursion, but they often provide mechanisms for looping as well.

Question 22

Apply-to-all functionality in functional languages is commonly provided by a function called?

Answer 22

Map

Question 23

Why are data structures in functional languages generally immutable?

Answer 23

Such that global state does not change, and thus correctness is maintained.

Question 24

Due to data structure immutability in functional languages, do modifications produce entirely new copies?

Answer 24

No, modifications are more efficiently implemented.

Question 25

How are pure functional languages defined?

Answer 25

As collections functions with no imperative constructs or mutability.

Question 26

What type of programming language is Haskell?

Answer 26

Pure functional.

Question 27

What type of programming language is Clojure?

Answer 27

A hybrid of functional and imperative.