Editing Coco/R (section)

{{Short description|Compiler generator}}
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{{Infobox software
| name = Coco/R
| logo = 
| screenshot = 
| caption = 
| author = [[Hanspeter Mössenböck]] and others
| developer = 
| released = 2005
| latest_release_version = 
| latest_release_date = 
| programming_language = 
| operating system = 
| platform = [[Cross-platform]]
| language = 
| genre = Parser/scanner generator
| license = [[GPL2]]
| website = {{URL|http://ssw.jku.at/Research/Projects/Coco/}}
}}

'''Coco/R''' is a [[compiler generator]] that takes [[wirth syntax notation]]{{r|name="manual"|p=6}}<ref group="note">In the manual, however, it is referred as [[L-attributed grammar|L-attributed]] [[Extended Backus–Naur Form]] syntax (EBNF).</ref> grammars of a source language and generates a scanner and a parser for that language.<ref name="manual">{{Cite web|last=Mössenböck|first=Hanspeter|last2=Kepler|first2=Johannes|title=The Compiler Generator Coco/R User Manual|url=https://ssw.jku.at/Research/Projects/Coco/Doc/UserManual.pdf|url-status=live|publisher=[[Johannes Kepler University Linz]], Institute of System Software|archive-url=https://web.archive.org/web/20120619124533/http://ssw.jku.at:80/Research/Projects/Coco/Doc/UserManual.pdf |archive-date=19 June 2012 }}</ref>

The [[Lexical analysis|scanner]] works as a [[deterministic finite automaton]].  It supports [[Unicode]] characters in [[UTF-8]] encoding and can be made case-sensitive or case-insensitive. It can also recognize tokens based on their right-hand-side context. In addition to terminal symbols the scanner can also recognize [[Compiler directive|pragmas]], which are tokens that are not part of the syntax but can occur anywhere in the input stream (e.g. compiler directives or end-of-line characters).

The [[parser]] uses [[recursive descent]]; [[LL parser|LL(1)]] conflicts can be resolved by either a multi-symbol lookahead or by semantic checks. Thus the class of accepted grammars is LL(k) for an arbitrary k. [[Fuzzy string searching|Fuzzy parsing]] is supported by so-called ANY symbols that match complementary sets of tokens. Semantic actions are written in the same language as the generated scanner and parser. The parser's error handling can be tuned by specifying synchronization points and "weak symbols" in the grammar. Coco/R checks the grammar for completeness, consistency, non-redundancy as well as for LL(1) conflicts.

There are versions of Coco/R for [[Java (programming language)|Java]], [[C Sharp (programming language)|C#]], [[C++]], [[Pascal (programming language)|Pascal]], [[Modula-2]], [[Modula-3]], [[Delphi (programming language)|Delphi]], [[VB.NET]], [[Python (programming language)|Python]], [[Ruby (programming language)|Ruby]] and other programming languages. The latest versions from the [[University of Linz]] are those for C#, Java and C++. For the Java version, there is an [[Eclipse (software)|Eclipse]] plug-in and for C#, a Visual Studio plug-in. There are also sample grammars for Java and C#.

Coco/R was originally developed at the [[ETHZ]] and moved with [[Hanspeter Mössenböck]] to [[Johannes Kepler University of Linz|University of Linz]] when he got his appointment there. Coco/R is distributed under the terms of a slightly relaxed [[GNU General Public License]].