Functional Programming Languages Overview

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Questions and Answers

What is required for a student to pass the lab component?

Average(testsAndAssignments) ≥ 50% and average(assignments) ≥ 30%

Average(tests) ≥ 30% and average(assignments) ≥ 20%

Average(tests) ≥ 20% and average(assignments) ≥ 30% (correct)

Average(tests) + average(assignments) ≥ 50%

How is the final exam weighted in the overall assessment?

25% of the final mark

100% of the final mark

50% of the final mark (correct)

75% of the final mark

In functional programming, how would you express the function call for squaring a number?

sq[ x ]

sq (x)

sq(x)

sq x (correct)

What determines the evaluation of an 'if-then-else' expression?

Only E is evaluated, then either ET or EF is executed. (A) Signup and view all the answers

What is a characteristic of pattern matching in function definitions?

Only the first matching pattern is executed. (D) Signup and view all the answers

What is the outcome of the expression `1:ns` when matched on the list `[1,2,3]`?

Binds ns to [2,3] (C) Signup and view all the answers

Which statement about recursion is true?

Linear recursive functions have a single recursive call each time they execute. (A) Signup and view all the answers

How does using patterns in code improve performance?

By enabling a clearer expression of the code's intent, leading to better optimization. (C) Signup and view all the answers

What is the base case for the Fibonacci function `fib n` when n is 1?

Returns 1 (A) Signup and view all the answers

What is a significant characteristic of the Ackermann-Péter function?

Its number of recursive calls increases extremely rapidly with its arguments. (B) Signup and view all the answers

Which programming language is the basis for the Sigma anti-spam system developed by Facebook?

Haskell (B) Signup and view all the answers

What key feature does Haskell offer that distinguishes it from other programming languages?

Lazy evaluation (D) Signup and view all the answers

What is the primary purpose of Lambda calculus as proposed by Alonzo Church?

To define the concept of computation (D) Signup and view all the answers

Which of the following is a proof assistant mentioned in the history of programming languages?

Isabelle (D) Signup and view all the answers

Which programming language integrates with the Java platform?

Clojure (A) Signup and view all the answers

What notable feature characterizes the ML programming language family?

Polymorphic types and type inference (C) Signup and view all the answers

Which of the following is NOT a known dialect of LISP?

Python (A) Signup and view all the answers

Which programming language is known for its immutability and laziness among multiparadigm languages?

Scala (D) Signup and view all the answers

What characteristic of functional programming ensures that there are no changes to variable states during execution?

Immutability (A) Signup and view all the answers

In the example provided, what is the purpose of the 'sq' function in the expression 'f x y'?

To calculate the square of the input (B) Signup and view all the answers

What is a primary advantage of using tail recursion in functional programming?

It reduces memory usage by optimizing call stack (A) Signup and view all the answers

Which of the following statements best describes mutually recursive functions?

They can call one another regardless of their order of definition. (C) Signup and view all the answers

Which of the following applications is NOT typically associated with functional programming?

Game development (D) Signup and view all the answers

What distinguishes a tail recursive function from a non-tail recursive function?

In a tail recursive function, the last action is calling itself. (B) Signup and view all the answers

Which of the following statements about the function 'fact' is true?

It performs additional multiplications after the recursive call. (B) Signup and view all the answers

What is the primary advantage of using a tail recursive function like 'factacc'?

It optimizes both space and time efficiency. (A) Signup and view all the answers

In the example of the function 'f x y', what does the 'where' clause define?

It creates local functions that can be used within the main function. (A) Signup and view all the answers

How does 'factacc' handle stack frames compared to the standard 'fact' function?

It overwrites previous stack frames, avoiding extra space usage. (D) Signup and view all the answers

In the factorial example, what value is returned when calling 'factacc 3 1'?

6 (D) Signup and view all the answers

What impact does tail recursion have on the execution of a function in Haskell?

It allows for certain optimizations during compilation. (D) Signup and view all the answers

What is the primary purpose of using local declarations in functions like 'f x y'?

To reduce code repetition and improve readability. (A) Signup and view all the answers

Study Notes

Introduction

Erlang is the language used by WhatsApp to manage 900 Million users.
Haskell is used by IOG in the Cardano blockchain platform.
Haskell is also used by Facebook for the Sigma anti-spam system.

Popular Functional Languages

Lambda Calculus is the theoretical basis for most functional programming languages
LISP: A functional language with ideas from Lambda Calculus.
- Basic blocks are atoms, lists, and forms.
- It allows variable change (considered a drawback).
- Popular dialects include Common LISP, Scheme, Racket, Clojure, and Hy.
- Common implementations are gcl (GNU Common LISP), CLISP, Steel Bank Common LISP, and Allegro CL.
ML (Meta Language): A functional language featuring polymorphic types and type inference.
- Common implementations include sml (Standard ML), polyML, Caml, and Objective Caml.
Miranda: A purely functional programming language.
Haskell: A purely functional language with lazy evaluation and standard Haskell 2010 report.
- It has a de facto standard implementation: ghc (Glasgow Haskell Compiler).

Multiparadigm Programming Languages

Multiparadigm languages allow the use of different programming paradigms.
Scala: A language featuring immutability, laziness, and a strong functional component.
There are requirements for passing the course that include assignments, tests, and an exam.

Haskell Examples

Define functions with types using the :: operator, example: sq :: Int -> Int; sq x = x * x.
Use : to call functions and \ for partial application, example: (1/ )
Use list comprehension and higher-order functions to sort lists, example: q (h:t) = q [s | s <- t, s > h].
Use pattern matching to define functions with different behaviors for various inputs, example: prodl [] = 1; prodl (n:ns) = n * prodl ns.
The if expression allows conditional execution.
Recursion is a key mechanism for loops in functional programming.
Tail recursion: functions that return either a directly computed value or the result of their recursive call.
Tail recursion can be more efficient than general recursion, as it avoids the need for a growing stack.

Don't Repeat Yourself (DRY)

Local declarations using where allow defining functions within a function.
Local declarations using let.. in allow defining functions within a function, but in a bottom-up approach.

Mutually Recursive Functions

Mutually recursive functions call each other.
The order of definition does not matter in Haskell for mutually recursive functions.

Summary

Functional programming (FP) uses functions as building blocks.
FP emphasizes pure functions with no side effects, variable changes, or state.
FP employs recursion and function composition.
Tail recursion is important for performance optimization.
Haskell and Elm are popular functional programming languages.

Studying That Suits You

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Description

Explore the fascinating world of functional programming languages, including their theoretical foundations and practical applications. Learn about popular languages like LISP, ML, Miranda, and Haskell, as well as their implementations and unique features. This quiz will help you understand the significance of each language in modern technology.