jflex-1.4.3.zip_Grammar_jflex 1.4.3_jflex-1.4.3.zip

------ Usage ------ Gerwin Klein <lsf37@users.sf.net> Régis Décamps <decamps@users.sf.net> ------ November 2, 2007 ------ About this project This sample project parses a grammar with JFlex. The project management is done with Maven. The project contains a simple grammar for the "Toy programming language". It is the example from the JLex web site with some small modifications, to make it a bit more readable. It does nothing really useful, because there is no parser for the toy programming language. It's just a demonstration how a small simple scanner looks like. * JFlex JFlex is a parser generator. Given a grammar, JFlex generate Java (TM) code to parse documents that follow this grammar. * Maven Maven is a project management framework. The project is described in as a POM (project object model, stored into <<<pom.xml>>>). This document isn't intended to be a tutorial on the use of Maven 2, you should consult the {{{http://maven.apache.org/}Maven web site}}. The integration of JFlex and Maven is done with {{{http://jflex.sourceforge.net/maven-flex-plugin/}maven-flex-plugin}}. Usage * mvn generate-sources The maven-jflex-plugin will read the grammar <<<src/main/jflex/simple.jflex>>> and generate a Java scanner <<<Yylex.java>>> in <<<target/generated-sources/flex>>> This is defined by the following section +--------- <build> <plugins> <plugin> <groupId>de.jflex.maven.plugin</groupId> <artifactId>maven-jflex-plugin</artifactId> <version>0.2</version> <executions> <execution> <goals> <goal>generate</goal> </goals> </execution> </executions> </plugin> </plugins> </build> +------------ By default, the maven-jflex-plugin generates a scanner/parser for every file in <<<src/main/jflex/>>>. * mvn test This goal test the generated scanner (if required, the lexer will be generated and all Java classes will be compiled) by running all tests in <<<src/test/java>>>. There is only one test in <<<src/test/java/YylexTest.java>>>. In this test, the scanner is run with the input file <<<src/test/resources/test.txt>>>. By default, the scanner outputs debugging information about each returned token to <<<System.out>>> until the end of file is reached, or an error occurs. But in the test, the output is redirected into <<<target/output.actual>>>. The test is successful if every line match with <<<src/test/resources/output.good>>>, which is the expected scanner debugging information. References * {{{http://jflex.sourceforge.net/maven-flex-plugin/}maven-flex-plugin}} * {{{http://maven.apache.org/}Maven web site}}.