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= FCL Passrc = FPC comes with a pascal parser in library form in the [[fcl-passrc]] package. This is not the main compiler parser, but it is the one used for [[fpdoc]] and [[pas2js]]. = Other FPC parser packages = [[fcl-xml]] is a FPC package that contains SAX XML and html parsers. FPC also contains two expression parsers [[symbolic]] and [http://wiki.freepascal.org/How_To_Use_TFPExpressionParser TFPExpressionParser]. = Lex and Yacc = Two of the oldest unix tools. [https://en.wikipedia.org/wiki/Lex_(software) Lex] is a lexical analyser (token parser), and [https://en.wikipedia.org/wiki/Yacc Yacc] is a [https://en.wikipedia.org/wiki/LALR_parser LALR] parser generator. [https://en.wikipedia.org/wiki/Backus–Naur_form BNF] notation is used as a formal way to express context free grammars. Code and grammar are mixed, so grammar is tied to implementation language. == Plex and Pyacc == [[Plex and Pyacc]] are pascal implementations of Lex and Yacc and they are part of your FreePascal distribution. == Lazarus Lex and Yacc == You can find unfortunately abandoned Lazarus Lex and Yacc [https://bitbucket.org/avra/lazlexyacc/src/master/ here]. = Gold = [[Gold]] is a free parsing system that you can use to develop your own programming languages, scripting languages and interpreters. It uses [https://en.wikipedia.org/wiki/LALR_parser LALR] parsing, and a mix of [https://en.wikipedia.org/wiki/Backus–Naur_form BNF] notation, character sets and regular expressions for terminals to define language grammars. Code and grammar are separated, so grammar is not tied to implementation language. This means that the same grammar can be loaded into engines made in different programming languages. Gold Parser Builder can be used to create, modify and test languages in Windows IDE which can also run on Wine. Command line tools are also available. Gold Parser Builder can also be used as a parser code generator using internal templates (FreePascal included), but there are also 3rd party engines to process compiled grammars. Gold Parser Builder has grammar editor with syntax highlighting, grammar generating wizard, test window to step through parsing of a sample source, templating system that can generate lexers/parsers or skeleton programs for various languages (including Delphi and FreePascal), import/export YACC/Bison, XML and HTML export, and interactive inspection of the compiled DFA and LALR tables. There is a subjective [http://goldparser.org/about/comparison-parsers.htm feature comparison table] of several parsers on Gold site, with special attention to [http://goldparser.org/about/comparison-yacc.htm Gold vs Yacc] comparison. = SynFacilSyn = [https://github.com/t-edson/SynFacilSyn SynFacilSyn] is Lazarus cross-platform library that includes a SynEdit highlighter that also can work as a lexer because of its flexible syntax definition file. It's well documented and has been used in several projects like highlighter and lexer. SynFacilSyn includes an adapter to be used in [https://github.com/Alexey-T/ATSynEdit ATSynEdit]. The main advantage of using SynFacilSyn as lexer is that you can really see the tokens colored in SynEdit editor, without doing anything else. So if you define a lexer, you are defining a source highlighter too. To define the syntax you can use an XML file, where the tokens are defined using tags and some RegEx constructions. There you can specify the token colors too, if you need it. Syntax definition can be done programmatically too, so it's possible to change some syntax elements in runtime. The highlighter of SynFacilSyn is light, fast and includes some useful methods to access the text content after the scan. Moreover includes some features to define recursive blocks ans sections so it can be used as a parser too. SynFacilSyn is the base library for other tools that in group can be used to create powerful compilers/interpreters/IDE: * [https://github.com/t-edson/SynFacilCompletion SynFacilCompletion] - Scriptable Highlighter with code-completion for the SynEdit Component of Lazarus * [https://github.com/t-edson/SynFacilUtils SynFacilUtils] Library with utilities to create editors using SynFacilSyn and SynFacilCompletion. * [https://github.com/t-edson/t-Xpres t-Xpres] Framework to create compilers/interpreters based on SynFacilSyn. Includes lexer, parser, syntaxTree, expression evaluator and support to implement code generators or virtual machines. The next programs have been created using this tools: * [https://github.com/t-edson/PicPas Microchip PIC compiler] * [https://github.com/t-edson/P65Pas 6502 CPU compiler] * [https://github.com/t-edson/Tito-s-Terminal Terminal with interpreter] = AntLR = TBD = Coco-R = Coco/R is a compiler generator based on L- attributed grammars which generates a scanner and a parser. For more information: http://www.ssw.uni-linz.ac.at/Coco/ Two chapters of this book give an introduction about Coco/R and show some sample studies. Compilers and Compiler Generators - an introduction with C++ P.D. Terry, Rhodes University, 1996 http://www.cs.ru.ac.za/compilers/index.html http://www.cs.ru.ac.za/compilers/pdfvers.pdf http://www.cs.ru.ac.za/compilers/cocorp.zip = Anatomy of a compiler = Here is graphical representation of a typical compiler anatomy: [[File:Anatomy of a compiler.gif|Anatomy of a compiler]] = Useful BNF and EBNF tools = * [http://www.garshol.priv.no/download/text/bnf.html BNF and EBNF metasyntax formal notations for writing grammars] * [http://bottlecaps.de/rr/ui EBNF to Syntax Diagram online convertor] * [https://sourceforge.net/projects/ebnfvisualizer/ EBNF Visualizer] * [https://www.ctan.org/tex-archive/support/syngen Syngen - tool for generating syntax diagrams from BNF in LaTeX format] = See also = * [https://www.inf.ethz.ch/personal/wirth/CompilerConstruction/ Compiler construction], by Niklaus Wirth. * ''Let's build a compiler'', by Jack Crenshaw; [https://compilers.iecc.com/crenshaw/ original site], [http://web.archive.org/web/20180107011717/http://www.stack.nl:80/~marcov/compiler.pdf PDF version], or [http://www.pp4s.co.uk/main/tu-trans-comp-jc-intro.html updated version]. * [http://www.cs.man.ac.uk/~pjj/farrell/compmain.html Compiler Basics] (August 1995), by James Alan Farrell * [https://norasandler.com/2017/11/29/Write-a-Compiler.html Writing a C Compiler, Part 1] (Nov 29, 2017), by Nora Sandler * [http://memphis.compilertools.net/interpreter.html Writing an interpreter] * [http://www.cs.man.ac.uk/~pjj/bnf/bnf.html Notations for context-free grammars] * [https://dickgrune.com/Books/PTAPG_1st_Edition/ Parsing Techniques - A Practical Guide] (1st ed., 1990), by Dick Grune and Ceriel J.H. Jacobs [[Category:Code]] [[Category:Compiler design]] [[Category:Utilities]]

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