- Yacc
The
computer program yacc is aparser generator developed byStephen C. Johnson atAT&T for theUnix operating system. The name is an acronym for "Yet Another Compiler Compiler ." It generates a parser (the part of acompiler that tries to make syntactic sense of thesource code ) based on an analytic grammar written in a notation similar to BNF. Yacc generates thecode for theparser in the C programming language.Yacc used to be available as the default parser generator on most Unix systems. It has since been supplanted as the default by more recent, largely compatible, programs such as
Berkeley Yacc ,GNU bison , MKS yacc and Abraxas pcyacc. An updated version of the original AT&T version is included as part of Sun'sOpenSolaris project. Each offers slight improvements and additional features over the original Yacc, but the concept has remained the same. Yacc has also been rewritten for other languages, includingRatfor , EFL, ML, Ada, Java, and Limbo.The parser generated by Yacc requires a
lexical analyzer . Lexical analyzer generators, such as Lex or Flex are widely available. TheIEEE POSIX P1003.2 standard defines the functionality andrequirement s for both Lex and Yacc.Some versions of AT&T Yacc have become
open source . For example,source code (for different implementations) is available with the standard distributions of Plan 9 andOpenSolaris .ee also
*
LALR parser : The underlying parsing algorithm in Yacc.
* Bison: The GNU version of Yacc.
* Lex (andFlex lexical analyser ), the token parser commonly used in conjunction with yacc (and Bison).
* BNF, is ametasyntax used to expresscontext-free grammar : that is, a formal way to describe formal languages.References
*Stephen C. Johnson. [http://www2.informatik.uni-erlangen.de/Lehre/WS200304/Compilerbau/Uebungen/yacc.pdf YACC: Yet Another Compiler-Compiler] . "Unix Programmer's Manual " Vol 2b, 1979.
External links
* [http://www.techworld.com.au/article/252319/-z_programming_languages_yacc Computerworld Interview with Stephen C. Johnson on YACC]
* [http://www.angelfire.com/dragon/letstry/tutorials/compiler/index.html Tutorial] a lex/yacc/compiler tutorial by Arnab Chakrobarty.
* [http://yaxx.sourceforge.net Yaxx] yacc variant written to avoid dependencies on any particular programming language.
* [http://invisible-island.net/byacc/byacc.html Berkeley Yacc] : yacc variant written to avoid dependencies on any particular C compiler.
* [http://www.informatik.uni-freiburg.de/proglang/software/essence/ Essence] , anLR(1) parser generator for Scheme
* [http://www.smlnj.org/doc/ML-Yacc/index.html ML-Yacc] a yacc version for the Standard ML language.
* [http://www.pps.jussieu.fr/~jch/software/cl-yacc/ CL-Yacc] , a LALR(1)parser generator forCommon Lisp .
* [http://www.erlang.org/faq/parsing.html Yecc] a yacc version for Erlang.
* [http://www.haskell.org/happy/ Happy] a yacc-like parser generator for Haskell.
* [http://www.dabeaz.com/ply PLY] a SLR and LALR(1) parser generator for Python
* [http://search.cpan.org/~casiano/Parse-Eyapp/ Eyapp] an extension of yacc for Perl
* A [http://epaperpress.com/lexandyacc/ Compact Guide] To lex & yacc
* TPYACC, a [http://www.musikwissenschaft.uni-mainz.de/~ag/tply/tply.htm Turbo Pascal or Delphi] version of YACC
* The [http://plas.fit.qut.edu.au/gppg/ Gardens Point Parser Generator] (GPPG), an implementation for C#
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