Просмотр исходного текста страницы Karel

{{Карточка языка программирования
|Ages=8, 9, 10
|FieldActivity=Empowered Learner, Computational Thinker
|Dimension=2D
|Purpose=Мини-язык для обучения
|Visual_Text_Blocks=Текст
|Openness=Открытый
|Address=http://karel.sourceforge.net/
|Ancestors=Josef
|Descendants=Karel++
}}
Karel the Robot has been one of the most widely-used mini-languages. It was designed by Richard Pattis in 1980s for university students taking their introductory programming course (Pattis and Pattis 1994; Ruf, Mühling, and Hubwieser 2014). Karel is a robot that inhabits a simple grid world with streets running east-west and avenues running north-south. Karel’s world can also contain immovable walls and beepers. Karel can move, turn, turn himself off, and sense walls half a block from him and beepers on the same corner as him. A Karel simulator allows students to watch the progress of their programs step by step. Karel was supported by a short textbook to help teachers incorporate Karel in their classes. The idea of the mini-language approach was to design a small and simple language to support the first steps in learning programming. The language included small set of commands that the actor can perform, and a set of value-returning queries and control structures. Most mini-languages include all basic control structures (conditional execution, looping, recursion, etc.) and a mechanism for creating some kind of sub-program. Karel contained main Pascal-like control structures to teach  basic concepts including sequential execution, procedural abstraction, conditional execution, and repetition. The overhead of full high-level programming languages was reduced as there are no variables, types or expressions in Karel.