MCQs on Modules and Libraries | Haskell

Modules and Libraries in Haskell Programming

Haskell is a powerful functional programming language that emphasizes immutability, purity, and type safety. Understanding how to organize code into modules, import and utilize libraries, and leverage the Haskell standard library is essential for writing effective, reusable code. This guide covers key concepts like organizing code into modules, importing libraries, and testing small libraries in Haskell.

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1. Organizing Code with Modules

1. What is the primary purpose of modules in Haskell?
   • a) To organize code into manageable units
   • b) To provide memory management
   • c) To create standalone executable files
   • d) To handle exceptions globally
2. How do you define a module in Haskell?
   • a) module ModuleName where
   • b) define ModuleName
   • c) import ModuleName
   • d) module : ModuleName
3. What is the benefit of using modules in Haskell?
   • a) Modularity and reusability of code
   • b) Simplified debugging process
   • c) Direct access to system hardware
   • d) Enhanced speed of execution
4. How can you expose functions from a Haskell module?
   • a) By declaring them in the module’s export list
   • b) By using export keyword
   • c) By importing the module into another file
   • d) By writing them in the main program
5. What does the keyword import do in a Haskell module?
   • a) It allows access to functions from another module
   • b) It defines a new module
   • c) It adds a new function to the module
   • d) It compiles the code
6. Which of the following is true about modules in Haskell?
   • a) Modules are used to define functions and types in a separate namespace
   • b) Modules cannot have functions with the same name
   • c) Haskell allows only one module per program
   • d) Modules cannot interact with each other
7. What is the default behavior of a function in a Haskell module if it is not exported?
   • a) The function is private and cannot be accessed outside the module
   • b) The function is global
   • c) The function will cause a compilation error
   • d) The function can only be accessed via imports
8. How can you hide specific functions when importing a module in Haskell?
   • a) By using hiding clause in the import statement
   • b) By using exclude keyword
   • c) By using noimport keyword
   • d) By commenting out the function
9. How do you specify a module to import selectively in Haskell?
   • a) import ModuleName (function1, function2)
   • b) import ModuleName only function1
   • c) import ModuleName without function2
   • d) import ModuleName selective
10. What does the qualified keyword do in Haskell imports?
    • a) It allows you to use functions from a module with a qualified name
    • b) It makes all functions in the module private
    • c) It imports only certain types
    • d) It changes the type of the module

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2. Importing and Using Libraries

11. How do you import a third-party library in Haskell?
    • a) By using the import keyword and specifying the library
    • b) By downloading the library manually
    • c) By using the use keyword
    • d) By linking the library in the .ghci file
12. Which package manager is commonly used to install libraries in Haskell?
    • a) Stack
    • b) npm
    • c) Maven
    • d) pip
13. How can you find libraries available for use in Haskell?
    • a) By searching on Hackage
    • b) By querying the compiler
    • c) By checking the system directory
    • d) By using ghc --libraries command
14. What must you include in your project to use an external library in Haskell?
    • a) The library name in the .cabal file
    • b) The library’s source code in your project
    • c) A direct link to the library’s GitHub page
    • d) The library’s license in your code
15. How do you install an external library in Haskell using Stack?
    • a) stack install library-name
    • b) cabal install library-name
    • c) stack get library-name
    • d) ghc -install library-name
16. What is the command to list installed libraries in Haskell using Stack?
    • a) stack list
    • b) ghc -list
    • c) stack show libraries
    • d) stack ghc --list
17. Which file is used to configure the dependencies of a Haskell project?
    • a) .cabal file
    • b) stack.yaml
    • c) ghci.conf
    • d) libconfig.yaml
18. What does the cabal tool do in Haskell?
    • a) It manages package dependencies and builds projects
    • b) It compiles code into executable binaries
    • c) It installs third-party libraries manually
    • d) It debugs Haskell programs
19. How do you import all functions from a Haskell library?
    • a) import LibraryName
    • b) import * from LibraryName
    • c) import LibraryName as *
    • d) import all from LibraryName
20. What does the import statement in Haskell allow you to do with a library?
    • a) It provides access to the library’s functions and types
    • b) It compiles the library into executable code
    • c) It automatically installs the library
    • d) It imports the library’s source code directly into your program

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3. Understanding the Haskell Standard Library

21. What is the Haskell standard library used for?
    • a) It provides basic functionality for common tasks like data manipulation and I/O
    • b) It only handles mathematical functions
    • c) It defines user interface elements
    • d) It manages network communication
22. Which module from the Haskell standard library provides functions for manipulating lists?
    • a) Data.List
    • b) System.IO
    • c) Control.Monad
    • d) Data.Map
23. What function from Data.Maybe is used to extract the value from a Just?
    • a) fromJust
    • b) unwrap
    • c) getValue
    • d) extract
24. Which module is commonly used to handle I/O operations in Haskell?
    • a) System.IO
    • b) Data.List
    • c) Control.Exception
    • d) Data.Map
25. What does the Control.Monad module provide in Haskell?
    • a) Functions for working with monads and chaining operations
    • b) Functions for controlling input/output operations
    • c) Data structures for storing large datasets
    • d) Functions for managing concurrency
26. What is the purpose of the Data.Map module in Haskell?
    • a) It provides an implementation of associative arrays (maps)
    • b) It handles file and directory operations
    • c) It works with mathematical sets
    • d) It defines basic list operations
27. How do you handle exceptions in Haskell using the standard library?
    • a) Using the Control.Exception module
    • b) Using the Data.Either module
    • c) Using the System.IO module
    • d) Using the Data.Maybe module
28. Which of the following is a function provided by the Data.List module in Haskell?
    • a) concat
    • b) append
    • c) sum
    • d) findIndex
29. Which Haskell library provides support for concurrent programming?
    • a) Control.Concurrent
    • b) Data.List
    • c) System.Process
    • d) Data.Map
30. What type of data does the Data.Either module work with in Haskell?
    • a) It works with values that can either be a success or a failure
    • b) It works with mathematical sets
    • c) It manages input/output data
    • d) It handles event-based data flow

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4. Writing and Testing Small Libraries

31. How do you write a small library in Haskell?
    • a) By defining functions and placing them in a module
    • b) By writing a large executable file
    • c) By adding functions directly into the main program
    • d) By creating a configuration file
32. What file should you use to configure a small library in Haskell?
    • a) .cabal file
    • b) Makefile
    • c) .haskell file
    • d) config.yaml
33. What is a good practice for testing small libraries in Haskell?
    • a) Using the HUnit testing framework
    • b) Using manual debugging techniques
    • c) Writing custom logging functions
    • d) Testing without writing specific test cases
34. Which function from the Test.HUnit module is used to run tests in Haskell?
    • a) runTestTT
    • b) runTests
    • c) testAll
    • d) executeTest
35. What is the purpose of the hspec library in Haskell?
    • a) It provides a behavior-driven testing framework
    • b) It handles file I/O operations
    • c) It manages concurrency in tests
    • d) It formats test results into reports

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Answers

Qno	Answer
1	a) To organize code into manageable units
2	a) module ModuleName where
3	a) Modularity and reusability of code
4	a) By declaring them in the module’s export list
5	a) It allows access to functions from another module
6	a) Modules are used to define functions and types in a separate namespace
7	a) The function is private and cannot be accessed outside the module
8	a) By using hiding clause in the import statement
9	a) import ModuleName (function1, function2)
10	a) It allows you to use functions from a module with a qualified name
11	a) By using the import keyword and specifying the library
12	a) Stack
13	a) By searching on Hackage
14	a) The library name in the .cabal file
15	a) stack install library-name
16	a) stack list
17	a) .cabal file
18	a) It manages package dependencies and builds projects
19	a) import LibraryName
20	a) It provides access to the library’s functions and types
21	a) It provides basic functionality for common tasks like data manipulation and I/O
22	a) Data.List
23	a) fromJust
24	a) System.IO
25	a) Functions for working with monads and chaining operations
26	a) It provides an implementation of associative arrays (maps)
27	a) Using the Control.Exception module
28	a) concat
29	a) Control.Concurrent
30	a) It works with values that can either be a success or a failure
31	a) By defining functions and placing them in a module
32	a) .cabal file
33	a) Using the HUnit testing framework
34	a) runTestTT
35	a) It provides a behavior-driven testing framework