Editing Yacc (section)

== History ==
In the early 1970s, [[Stephen C. Johnson]], a computer scientist at [[Bell Labs]] / [[AT&T Corporation|AT&T]], developed Yacc because he wanted to insert an [[exclusive or]] operator into a [[B (programming language)|B language]] compiler<ref name="red">{{cite news|last1=Morris|first1=Richard|title=Stephen Curtis Johnson: Geek of the Week|url=https://www.red-gate.com/simple-talk/opinion/geek-of-the-week/stephen-curtis-johnson-geek-of-the-week/|access-date=19 January 2018|work=Red Gate Software|date=1 October 2009}}</ref> (developed using [[Douglas McIlroy|McIlroy]]'s [[TMG (language)|TMG]] compiler-compiler<ref name="Chistory"/>), but it turned out to be a hard task. As a result, he was directed by his colleague at Bell Labs [[Al Aho]] to [[Donald Knuth]]'s work on [[LR parser|LR parsing]], which served as the basis for Yacc.<ref name="red">{{cite news|last1=Morris|first1=Richard|title=Stephen Curtis Johnson: Geek of the Week|url=https://www.red-gate.com/simple-talk/opinion/geek-of-the-week/stephen-curtis-johnson-geek-of-the-week/|access-date=19 January 2018|work=Red Gate Software|date=1 October 2009}}</ref> Yacc was influenced by<ref name="Yacc: Yet Another Compiler-Compiler"/> and received its name in reference to TMG compiler-compiler.<ref>{{cite web|title=Early Translator Writing Systems |url=http://www.chilton-computing.org.uk/acl/applications/cc/p007.htm |publisher=Atlas Computer Laboratory}}</ref>

Yacc was originally written in the [[B (programming language)|B programming language]], but was soon rewritten in [[C (programming language)|C]] by Alan Snyder.<ref name="Chistory">{{cite conference
|last=Ritchie
|first=Dennis M.
|author-link=Dennis Ritchie
|date=April 1993
|title=The Development of the C Language
|publisher=Association for Computing Machinery, Inc.
|doi=10.1145/234286.1057834
|doi-access=free
|book-title=History of programming languages---II
|language=en
|isbn=0-201-89502-1
|publication-date=1996-01-01
|quote=After the TMG version of B was working, Thompson rewrote B in itself(a bootstrapping step).…When Johnson returned to Bell Labs in 1973, he was disconcerted to find that the language whose seeds he had brought to Canada had evolved back home; even his own yacc program had been rewritten in C, by Alan Snyder.
|quote-pages=675,684
}}
</ref> It appeared as part of [[Version 3 Unix]],<ref name="reader">{{cite tech report |first1=M. D. |last1=McIlroy |author-link1=Doug McIlroy |year=1987 |url=http://www.cs.dartmouth.edu/~doug/reader.pdf |title=A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986 |series=CSTR |number=139 |institution=Bell Labs}}</ref> and a full description of Yacc was published in 1975.<ref name="Yacc: Yet Another Compiler-Compiler">{{cite tech report |last=Johnson|first=Stephen C.|author-link=Stephen C. Johnson|year=1975|title=Yacc: Yet Another Compiler-Compiler|number=32|publisher=AT&T Bell Laboratories|location=Murray Hill, New Jersey|url=http://dinosaur.compilertools.net/yacc/|access-date=31 January 2020}}</ref>

Johnson used Yacc to create the [[Portable C Compiler]].<ref name="reader"/> [[Bjarne Stroustrup]] also attempted to use Yacc to create a formal specification of [[C++]], but "was defeated by C's syntax".<ref name="hopl2">{{cite web|last=Stroustrup|first=Bjarne |author-link=Bjarne Stroustrup |title=A History of C++: 1979−1991|url=http://www.stroustrup.com/hopl2.pdf}}</ref> While finding it unsuitable for a formal specification of the language, Stroustrup did proceed to use Yacc to implement [[Cfront]], the first implementation of C++.<ref name="oldcfront">{{cite web|last=Stroustrup|first=Bjarne |author-link=Bjarne Stroustrup |title=Cfront source code|url=http://www.softwarepreservation.org/projects/c_plus_plus/index.html#cfront}}</ref>

In a 2008 interview, Johnson reflected that "the contribution Yacc made to the spread of [[Unix]] and [[C (programming language)|C]] is what I'm proudest of".<ref name="cw">{{
cite news
|url=https://www.computerworld.com/article/2534771/yacc--unix--and-advice-from--bell-labs-alumni-stephen-johnson.html
|title=Yacc, Unix, and advice from Bell Labs alumni Stephen Johnson
|last1=Hamilton
|first1=Naomi
|date=2008-07-09
|website=www.computerworld.com
|access-date=2020-11-10
|url-status=live
|archive-url=https://web.archive.org/web/20200822224200/https://www.computerworld.com/article/2534771/yacc--unix--and-advice-from--bell-labs-alumni-stephen-johnson.html
|archive-date=2020-08-22
}}</ref>