Referential transparency lets programmers and compilers to think of code as a rewrite system—something that takes an expression and replaces it with something else. This can help with several tasks, such as:
There are several ways of doing the last task—the most well-known are memoization (saving answers after the first time), common subexpression elimination (figuring out if it is worth it to combine two parts of the code that are the same) , lazy evaluation (not finding the answer until the code really needs it), and parallelization (working on multiple problems at the same time).
Walter Harris (author)
Walter Harris (15 October 1925 – 9 May 2019) was a British author and broadcaster. He wrote ten books and had many poetry volumes published. His first book was "Clovis" (1970), and his last was "Godhead" (2014). He worked for the BBC and interviewed Peter Cook, Dudley Moore, Alan Bennett and Jonathan Miller on the opening night of "Beyond the Fringe", as well as Danny Kaye, John Wayne and W. Somerset Maugham. Recordings of his interviews and broadcasts are held at the BBC Sound Archive and the British Library.
Harris died on 9 May 2019, at the age of 93.
Nan Winton
Nancy Wigginton (1925 – 11 May 2019), better known as Nan Winton, was a British broadcaster. She is best known for being the first female newsreader on BBC television. After her first news broadcaster on 20 June 1960, she worked for ITV. She was also a regular panellist on the radio panel game "Treble Chance".
Winton was born in Portsmouth, Hampshire. She was married to actor Charles Stapley from 1948 to 1962. The couple had two children. On 11 May 2019, Winton died from congestive heart failure and hypertension after having a fall at her home in Dorchester, Dorset. She was 93.
Jean Beaudin
Jean Beaudin (6 February 1939 – 18 May 2019) was a Canadian movie director and screenwriter. He directed 20 movies, including French-language movies "J.A. Martin Photographer" (1977), "The Alley Cat" (1985), "Being at Home with Claude" (1992) and "The Collector" (2002). He was born in Montreal, Quebec. Beaudin's partner of more than 20 years was actress Domini Blythe (1947–2010).
Beaudin died on 18 May 2019, at the age of 80.
Jonathan Miller
Sir Jonathan Wolfe Miller (21 July 1934 – 27 November 2019) was a British theatre and opera director, actor, author, television presenter and medical doctor. He was born in St John's Wood, London. He first became well-known in the early 1960s in the comedy revue "Beyond the Fringe" with Peter Cook, Dudley Moore and Alan Bennett.
Miller started directing operas in the 1970s. His best-known production was probably his 1982 "Mafia"-styled "Rigoletto" set in the 1950s. He was an associate director at the National Theatre and later ran the Old Vic Theatre. He was a writer and presenter of many BBC documentaries.
Miller was married to Rachel Collet from 1956 until his death. The couple had three children.
Miller died at his home in Camden, London of Alzheimer's disease-related problems on 27 November 2019. He was 85.
Side effect (computer science)
A part of a program with a side effect performs a noticeable action other than giving back a value. Examples include showing a picture on a computer screen, or checking what year it is. Code with side effects can be harder to understand without any context, and the order of instructions more important for code with side effects.
In functional programming, programmers try to avoid side effects when they can, so it is easier to prove that a program will always do what it is supposed to. In some functional languages, like Standard ML, Scheme, or Scala, side effects are not restricted, but programmers still try to use them less. In Haskell, actions with side effects must be stated explicitly—this makes it easier to tell what code does or does not have them.
Mars Climate Orbiter
The Mars Climate Orbiter was a space probe. It was launched by NASA on 11 December 1998 to study the Martian climate and Martian atmosphere. However, on 23 September 1999, communication with the spacecraft was lost, when the spacecraft was about to enter orbit. Because the computer software was working with non-SI units instead of the SI units. The spacecraft entered Mars on an orbit that brought it too close to the planet. However, what happened with the probe is still unknown, either it was destroyed in the atmosphere or entered in an orbit around the Sun after leaving the Martian atmosphere.
Glauco Sansovini
Glauco Sansovini (20 May 1938 – 21 May 2019) was a Sammarinese politician. He served as one of the Captains Regent of San Marino together with Marco Conti from 1 April 2010 to 1 October 2010. He was born in Rocca San Casciano, Italy.
Sansovini died on 21 May 2019 in Borgo Maggiore, a day after his 81st birthday.
Neville Lederle
Neville Lederle (25 September 1938 – 17 May 2019) was a South African racing driver. He raced in two Formula One World Championship Grand Prix. His two F1 appearances were in the and South African Grand Prix. He scored a single F1 championship point. He was born in Theunissen, Orange Free State.
Lederle died at his home in Knysna on 17 May 2019, at the age of 80.
Scala (Programming language)
Scala is a general-purpose programming language—a language that is designed for solving all kinds of problems, not just a specific one.
It provides support for functional programming, and is statically typed. It is designed to fix some problems with Java, and to be concise—to be able to express a lot with only a little bit of code.
Scala code is supposed to be compiled into Java bytecode, so Scala code can be run on a Java Virtual Machine (JVM). Scala has language interoperability with Java—Scala code can be used in Java programs, and the other way around.
William Wyatt Bibb
William Wyatt Bibb (2 October 1781 – 10 July 1820) was a United States Senator from Georgia. He was the first Governor of the U.S. state of Alabama. Bibb County, Alabama, and Bibb County, Georgia, are named for him.
He was a member of the Democratic-Republican political party. Bibb served as governor of the Alabama Territory from August 1817 to December 1819, and as the first elected governor of the state of Alabama from December 1819 to his death on July 10, 1820.
Shispare
Shispare is a mountain in the Karakoram range, in Pakistan. It is the 38th highest mountain in the world. The first people to reach the top were H. Bleicher, L. Cichy, M. Grochowski, J. Holnicki-Szulc, A. Mlynarczyk, H. Oberhofer, and J. Poreba, in 1974.
Piet Blauw
Pieter Marinus "Piet" Blauw (30 September 1937 – 16 May 2019) was a Dutch politician and farmer. He was a member of the People's Party for Freedom and Democracy (VVD). He became a member of the House of Representatives in 1981, serving until 1998. He born in Alkmaar, North Holland.
Blauw died on 16 May 2019 in Veendam, Groningen. He was 81.
TEC-9
The Intratec TEC-9, also called a TEC-DC9, KG-99, or AB-10, is a blowback-operated semi-automatic pistol.
Artemis program
The Artemis program is a human spaceflight program planned by the National Aeronautics and Space Administration (NASA), American private spaceflight companies and international partners. The goal of the program is to land the first woman and the next man on the Moon by 2024.
Khwe language
Khwe (also rendered "Kxoe, Khoe"; or ) is a dialect continuum of the Khoe family of Namibia, Angola, Botswana, South Africa, and parts of Zambia, with some 8,000 speakers.
Information commissioner
An information commissioner is a government-appointed person who controls a country's laws regarding data. In the United Kingdom these are laws such as the Data Protection Act.
Value (computer science)
A value is a piece of information that can be used by a program. A group of values is sometimes called a type.
Manual labour