Zipper

A zipper, zip, fly or zip fastener, formerly known as a clasp locker, is a commonly used device for binding the edges of an opening of fabric or other flexible material, like on a garment or a bag. It is used in clothing (e.g., jackets and jeans), luggage and other bags, sporting goods, camping gear (e.g. tents and sleeping bags), and other items. Whitcomb L. Judson was an American inventor from Chicago who was the first to invent, conceive of the idea, and to construct a workable zipper. The method, still in use today, is based on interlocking teeth. Initially it was called the “hookless fastener” and was later redesigned to become more reliable.

Description

The bulk of a zipper/zip consists of two rows of protruding teeth, which may be made to interdigitate, linking the rows, carrying from tens to hundreds of specially shaped metal or plastic teeth. These teeth can be either individual or shaped from a continuous coil, and are also referred to as elements. The slider, operated by hand, moves along the rows of teeth. Inside the slider is a Y-shaped channel that meshes together or separates the opposing rows of teeth, depending on the direction of the slider's movement. The word Zipper is onomatopoetic, because it was named for the sound the device makes when used, a high-pitched zip.

Zipper (data structure)

A zipper is a technique of representing an aggregate data structure so that it is convenient for writing programs that traverse the structure arbitrarily and update its contents, especially in purely functional programming languages. The zipper was described by Gérard Huet in 1997. It includes and generalizes the gap buffer technique sometimes used with arrays.

The zipper technique is general in the sense that it can be adapted to lists, trees, and other recursively defined data structures. Such modified data structures are usually referred to as "a tree with zipper" or "a list with zipper" to emphasize that the structure is conceptually a tree or list, while the zipper is a detail of the implementation.

A layman's explanation for a tree with zipper would be an ordinary computer filesystem with operations to go to parent (often cd ..), and the possibility to go downwards (cd subdirectory). The zipper is the pointer to the current path. Behind the scenes the zippers are efficient when making (functional) changes to a data structure, where a new, slightly changed, data structure is returned from an edit operation (instead of making a change in the current data structure).

Zipper (film)

Zipper is a 2015 political thriller film, written and directed by Mora Stephens, starring Patrick Wilson, Lena Headey, Dianna Agron, Richard Dreyfuss, Ray Winstone, and Penelope Mitchell. The film had its world premiere on January 27, 2015 at the Sundance Film Festival. The film was released on August 28, 2015, in a limited release in the United States and through video on demand by Alchemy. The film follows a federal prosecutor running for office who cannot stop himself from sleeping with high-class escorts, putting both his career and his personal life at risk.

Plot

Sam Ellis (Patrick Wilson) is a man on the rise – a hot-shot prosecutor on the cusp of a bright future. When an intern (Dianna Agron) at the office becomes infatuated with him, Sam unwisely attempts to quiet his desires by seeing a high class escort — only to discover that the experience is more fulfilling and exhilarating than he could have imagined. A second appointment with an escort soon follows, and a third, sending his once idyllic life spiraling out of control. In the midst of wrestling with his demons, he suddenly finds himself being groomed to run for Attorney General — thrusting him into the public spotlight, and forcing him to take increasingly dangerous measures to keep the press, the law and his wife (Lena Headey) off his trail.