Section 12 - Functional programming Flashcards
What is a programming paradigm?
A style of computer programming
What are the 4 types of programming paradigms?
- Procedural programming
- Object-orientated programming
- Declarative programming
- Functional programming
What is procedural programming?
Where a series of instructions tells the computer what to do with the input in order to solve the problem
What is structured programming?
A form of procedural programming which uses the modular techniques to split large programs into manageable chunks
What programming constructs does structured programming use?
- Sequence
- Selection
- Iteration
- Recursion
What is object-orientated programming?
A programming paradigm comprised of classes of objects. It is was developed to make it possible to abstract details of implementation away from the user, making code reusable and programs easy to maintain
What is declarative programming?
Where you write statements the describe the problem to be solved, with the language implementation deciding the best way to solve it
What is functional programming?
Functions are used as the fundamental building blocks of a program, where statements are written as a series of functions which accept input data as arguments and return an output
What is a function?
A mapping from the domain to the co-domain
What is the domain?
The set of inputs
What is the co-domain?
The set of possible outputs
What is always true about the domain and co-domain?
They are always subsets of objects in some data type
What is Haskell?
A functional programming language
What is a parameter in Haskell?
A reference declared in a function declaration
What is an argument in Haskell?
A value or expression passed to a function
What is function application?
The process of giving particular inputs to a function
What are first-class objects?
An object that can:
- Appear in expressions
- Be assigned to a variable
- Be assigned as an argument
- Be returned in a function call
What is unique about variables in functional programming?
The value of a variable is immutable and the program is stateless
What is referential transparency?
A function that is called twice with the same parameters will always return the same result
What is the advantage of referential transparency?
It is relatively easy to write correct, bug free programs
What does it mean to have no side effects?
The only thing a function can do is calculate something and return a result so it has no side effects
What is functional composition?
Combining 2 functions to get a new function, by using a function as an argument
What are types?
Sets of values
What are typeclasses?
Sets of types
What is a type variable?
A variable that represents any type
What is a higher order function?
A function that either takes a function as an argument or returns a function as a result
How many arguments can a function in Haskell take?
Only 1, because each argument will result in a new function being created
What is partial function application?
Fixing the values of some inputs to a function in order to produce another more specific function
What is the map function?
A higher-order function that takes a list, treats each element as an input and applies the function to each element, returning a new list
What is a list?
A collection of elements of the same type, enclosed in square brackets
What is the max function?
A built-in library function that returns the maximum of 2 numbers
What is the filter function?
A higher-order function that takes a predicate and a list, returning the elements within the list that satisfies the Boolean condition
What is a predicate?
A boolean condition
What is a fold function?
A higher-order function that reduces a lost to a single value via recursion
What is the difference between foldl and foldr?
Foldl has the recursion starting at the leftmost value, Foldr has the recursion starting at the rightmost value
What is the head of a list?
The first element in the list
What is the tail of a list?
The last element in the list
Can lists be modified?
No, they are immutable
What does the function null do?
It tests for an empty list
What is prepending?
Adding an element to the front of the list
What is appending?
Adding an element to the end of a list
