What is "escher"

Escher is a surname. Notable people with the surname include:

• Alfred Escher (1819−1883), a Swiss politician and railway pioneer
• Arnold Escher von der Linth (1807−1872), a Swiss geologist
• Arthur Escher (born 1928), a Dutch geologist, first ascendent of Puncak Mandala, son of M.C. Escher
• Berend George Escher (1885−1967), a Dutch geologist, half-brother of M.C. Escher
• George Arnold Escher (1843−1939), a Dutch civil engineer, foreign advisor to Japan, father of M.C. Escher
• Gitta Escher (born 1957), a German gymnast

• (1775-1859), a Swiss industrialist and co-founder of Escher Wyss AG

• Hans Conrad Escher von der Linth (1767−1823), a Swiss scientist, civil engineer and politician

• (1743−1814), a Swiss politician

• Heinrich Escher (1626−1710), a Swiss politician, mayor of Zürich
• Josef Escher (1885−1954), a Swiss Federal Councilor
• Luiz Jeferson Escher (born 1987), Brazilian footballer
• Lydia Escher (1858−1891), a Swiss patron of the arts
• M. C. Escher, Maurits Cornelis Escher (1898−1972), a Dutch graphic artist
• Rudolf George Escher (1912−1980), a Dutch composer and music theoretician
• Sandra Escher (born 1945), a Dutch psychiatrist
• William J.D. Escher (1931–2014), an American aerospace engineer

Escher is a declarative programming language that supports both functional programming and logic programming models, developed by J.W. Lloyd in the mid-1990s. It was designed mostly as a research and teaching vehicle. The basic view of programming exhibited by Escher and related languages is that a program is a representation of a theory in some logic framework, and the program's execution (computation) is a deduction from the theory. The logic framework for Escher is Alonzo Church's simple theory of types.

Escher, notably, supports I/O through a monadic type representing the 'outside world', in the style of Haskell. One of the goals of Escher's designers was to support meta-programming, and so the language has comprehensive support for generating and transforming programs.