Search results
Results From The WOW.Com Content Network
A classic example are the data structures used representing characters in a word processor. Naively, each character in a document might have a glyph object containing its font outline, font metrics, and other formatting data. However, this would use hundreds or thousands of bytes of memory for each character.
Model–view–viewmodel (MVVM) is an architectural pattern in computer software that facilitates the separation of the development of a graphical user interface (GUI; the view)—be it via a markup language or GUI code—from the development of the business logic or back-end logic (the model) such that the view is not dependent upon any ...
Folds can be regarded as consistently replacing the structural components of a data structure with functions and values. Lists, for example, are built up in many functional languages from two primitives: any list is either an empty list, commonly called nil ([]), or is constructed by prefixing an element in front of another list, creating what is called a cons node ( Cons(X1,Cons(X2,Cons ...
The observer design pattern is a behavioural pattern listed among the 23 well-known "Gang of Four" design patterns that address recurring design challenges in order to design flexible and reusable object-oriented software, yielding objects that are easier to implement, change, test and reuse.
Sigma function: Sums of powers of divisors of a given natural number. Euler's totient function: Number of numbers coprime to (and not bigger than) a given one. Prime-counting function: Number of primes less than or equal to a given number. Partition function: Order-independent count of ways to write a given positive integer as a sum of positive ...
For example, the expression: print length([2+1, 3*2, 1/0, 5-4]) fails under strict evaluation because of the division by zero in the third element of the list. Under lazy evaluation, the length function returns the value 4 (i.e., the number of items in the list), since evaluating it does not attempt to evaluate the terms making up the list.
The Dutch national flag problem [1] is a computational problem proposed by Edsger Dijkstra. [2] The flag of the Netherlands consists of three colors: red, white, and blue. Given balls of these three colors arranged randomly in a line (it does not matter how many balls there are), the task is to arrange them such that all balls of the same color ...
One example of how this can be used is to restore an object to its previous state (undo via rollback), another is versioning, another is custom serialization. The memento pattern is implemented with three objects: the originator, a caretaker and a memento. The originator is some object that has an internal state.