4.12: section 12: OOP and functional programming

process of giving particular inputs to a function

f: A ->B f = function A = argument type: set of inputs =domain B = result type set of outputs = co-domain A and B must be subsets of objects in some data type

• although it seems multiple functions are being passed through only 1 is actually being applied • instead the result and function are passed as inputs

takes advantage of the inability of a function to take more than one input -one of the arguments is fixed leading to a more restricted specialized function

operation functional composition combines two functions to get a new function.

A function is higher-order if it takes a function as an argument or returns a function as a result, or does both.

a higher-order function that applies a given function to each element of a list, returning a list of results.

a higher-order function that processes a data structure, typically a list, in some order to produce a new data structure containing exactly those elements of the original data structure that match a given condition.

a higher-order function which reduces a list of values to a single value by repeatedly applying a combining function to the list values. -can be started from the left or right of the list

head: first element in a list tail: all remaining elements

head list_Name

tail list_Name

null list_Name

list_Name = []

length list_Name

newValue: list_Name or [newValue] ++list_Name this doesnt change the list but instead cretaes a new one as the values are immutable

list_Name ++ [newValue] or create a function that reverses the list, prepends the value and reverses the list again let append y (x:xs) = reverse(y:reverse(x:xs))