Editing Logo (programming language) (section)

{{Short description|Computer programming language}}
{{Infobox programming language
| name = Logo
| logo = 
| logo caption = 
| screenshot = KochTurtleAnim.gif
| screenshot caption = [[L-system#Example 4: Koch curve|L-system (Koch curve)]] turtle graphic
| paradigms = [[Multi-paradigm programming language|Multi-paradigm]]: [[Functional programming|functional]], [[Educational programming language|educational]], [[Procedural programming|procedural]], [[Reflective programming|reflective]]
| family = [[Lisp (programming language)|Lisp]]
| designers = [[Wally Feurzeig]], [[Seymour Papert]], [[Cynthia Solomon]]
| developer = [[BBN Technologies|Bolt, Beranek and Newman]]
| released = {{Start date and age|1967}}
| typing = [[Dynamic typing|dynamic]]
| implementations = [[UCBLogo]], many others
| dialects = [[StarLogo]], [[NetLogo]] and [[AppleLogo]]
| influenced = [[AgentSheets]], [[NetLogo]], [[Smalltalk]], [[Etoys (programming language)|Etoys]], [[Scratch (programming language)|Scratch]], [[Microsoft Small Basic]], KTurtle, [[REBOL]], [[Boxer (programming environment)|Boxer]]
| influenced by = [[Lisp (programming language)|Lisp]]
}}
[[File:Remi_turtlegrafik.png|thumb|Symmetry around a point can be obtained using only a few instructions, allowing users to draw [[hypotrochoid]]s like the one shown here.]]
'''Logo''' is an [[list of educational programming languages|educational programming language]], designed in 1967 by [[Wally Feurzeig]], [[Seymour Papert]], and [[Cynthia Solomon]].<ref>{{Cite journal |url=https://dspace.mit.edu/handle/1721.1/6226 |title=Logo Manual |last1=Abelson |first1=Hal |last2=Goodman |first2=Nat |date=December 1974 |website=Artificial Intelligence Lab, Massachusetts Institute of Technology |access-date=August 28, 2016 |last3=Rudolph |first3=Lee |hdl=1721.1/6226 |url-status=live |archive-url=https://web.archive.org/web/20160911020834/https://dspace.mit.edu/handle/1721.1/6226 |archive-date=September 11, 2016 }}</ref> The name was coined by Feurzeig while he was at [[Raytheon BBN|Bolt, Beranek and Newman]],<ref name="goldenberg198208">{{cite news |url=https://archive.org/stream/byte-magazine-1982-08/1982_08_BYTE_07-08_Logo#page/n209/mode/2up |title=Logo – A Cultural Glossary |last=Goldenberg |first= E. Paul |date=August 1982 |work=Byte |access-date=19 October 2013|pages=218}}</ref> and derives from the Greek ''logos'', meaning 'word' or 'thought'.

A general-purpose language, Logo is widely known for its use of [[turtle graphics]], in which commands for movement and drawing produced line or [[vector graphics]], either on screen or with a small robot termed a [[Turtle (robot)|turtle]]. The language was conceived to teach concepts of programming related to [[Lisp (programming language)|Lisp]] and only later to enable what Papert called "[[Proprioception|body-syntonic]] reasoning", where students could understand, predict, and reason about the turtle's motion by imagining what they would do if they were the turtle. There are substantial differences among the many dialects of Logo, and the situation is confused by the regular appearance of turtle graphics programs that are named Logo.

Logo is a [[Comparison of multi-paradigm programming languages|multi-paradigm]] adaptation and dialect of Lisp, a [[functional programming]] language.<ref name=cslsPreface >CSLS Vol 1, Preface .pxvi, Harvey 1997</ref> There is no standard Logo, but [[UCBLogo]] has the facilities for handling lists, files, I/O, and [[Recursion (computer science)|recursion]] in scripts, and can be used to teach all computer science concepts, as [[University of California, Berkeley|UC Berkeley]] lecturer [[Brian Harvey (lecturer)|Brian Harvey]] did in his ''Computer Science Logo Style'' trilogy.<ref name=csls>''Computer Science Logo Style'', Brian Harvey, MIT Press (3 volumes) {{ISBN|0-262-58148-5}}, {{ISBN|0-262-58149-3}}, {{ISBN|0-262-58150-7}}. Available [http://www.cs.berkeley.edu/~bh/ online] {{webarchive |url=https://web.archive.org/web/20130704014342/http://www.cs.berkeley.edu/~bh/ |date=2013-07-04 }}</ref>

Logo is usually an [[Interpreter (computing)|interpreted language]], although compiled Logo dialects (such as Lhogho and Liogo) have been developed. Logo is not case-sensitive but retains the case used for formatting purposes.