JFlex Maven Plugin

This is a Maven 3 plugin to generate Lexer code in Java from a Lexer specification, using JFlex.

License

License

BSD
Categories

Categories

Maven Build Tools JFlex Compiler-compiler
GroupId

GroupId

de.jflex
ArtifactId

ArtifactId

jflex-maven-plugin
Last Version

Last Version

1.8.2
Release Date

Release Date

Type

Type

maven-plugin
Description

Description

JFlex Maven Plugin
This is a Maven 3 plugin to generate Lexer code in Java from a Lexer specification, using JFlex.
Project Organization

Project Organization

JFlex
Source Code Management

Source Code Management

https://github.com/jflex-de/jflex/tree/master/jflex-maven-plugin

Download jflex-maven-plugin

How to add to project

<plugin>
    <groupId>de.jflex</groupId>
    <artifactId>jflex-maven-plugin</artifactId>
    <version>1.8.2</version>
</plugin>

Dependencies

compile (5)

Group / Artifact Type Version
com.google.code.findbugs : jsr305 jar 3.0.2
com.google.guava : guava jar 20.0
de.jflex : jflex jar 1.8.2
org.apache.maven : maven-plugin-api jar 3.5.2
org.apache.maven : maven-core jar 3.5.2

provided (1)

Group / Artifact Type Version
org.apache.maven.plugin-tools : maven-plugin-annotations jar 3.5.2

test (4)

Group / Artifact Type Version
org.apache.maven : maven-compat jar 3.5.2
org.apache.maven.plugin-testing : maven-plugin-testing-harness jar 3.3.0
com.google.truth : truth jar 0.42
junit : junit jar 4.12

Project Modules

There are no modules declared in this project.

Build Bazel build status

JFlex

JFlex is a lexical analyzer generator (also known as scanner generator) for Java.

JFlex takes as input a specification with a set of regular expressions and corresponding actions. It generates Java source of a lexer that reads input, matches the input against the regular expressions in the spec file, and runs the corresponding action if a regular expression matched. Lexers usually are the first front-end step in compilers, matching keywords, comments, operators, etc, and generating an input token stream for parsers.

JFlex lexers are based on deterministic finite automata (DFAs). They are fast, without expensive backtracking.

Usage

For documentation and more information see the JFlex documentation and the wiki.

Usage with Maven

Maven central

You need Maven 3.5.2 or later, and JDK 8 or later.

  1. Place grammar files in src/main/flex/ directory.

  2. Extend the project POM build section with the maven-jflex-plugin

  <build>
    <plugins>
      <plugin>
        <groupId>de.jflex</groupId>
        <artifactId>jflex-maven-plugin</artifactId>
        <version>1.8.2</version>
        <executions>
          <execution>
            <goals>
              <goal>generate</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
  1. Voilà: Java code is produced in target/generated-sources/ during the generate-sources phase (which happens before the compile phase) and included in the compilation scope.

Usage with ant

You need ant, the binary jflex jar and JDK 8 or later.

  1. Define ant task
<taskdef classname="jflex.anttask.JFlexTask" name="jflex"
         classpath="path-to-jflex.jar"/>
  1. Use it
<jflex file="src/grammar/parser.flex" destdir="build/generated/"/>
<javac srcdir="build/generated/" destdir="build/classes/"/>

Usage with Bazel

We provide a jflex rule

load("@jflex_rules//jflex:jflex.bzl", "jflex")

jflex(
    name = "",           # Choose a rule name
    srcs = [],           # Add input lex specifications
    outputs = [],        # List expected generated files
)

See the sample simple BUILD file.

Usage in CLI

You need the binary jflex jar and JDK 8 or later.

You can also use JFlex directly from the command line:

jflex/bin/jflex src/grammar/parser.flex

Or:

java -jar jflex-full-1.8.2.jar -d output src/grammar/parser.flex

Other build tools

See Build tool plugins.

Examples

Have a look at the sample project: simple and other examples.

Contributing

Javadoc

JFlex is free software, contributions are welcome. See the Contributing page for instructions.

Source layout

The top level directory of the JFLex git repository contains:

  • cup A copy of the CUP runtime
  • cup-maven-plugin A simple Maven plugin to generate a parser with CUP.
  • docs the Markdown sources for the user manual
  • java Java sources [WIP, Bazel]
  • javatests Java sources of test [WIP, Bazel]
  • jflex JFlex, the scanner/lexer generator for Java
  • jflex-maven-plugin the JFlex maven plugin, that helps to integrate JFlex in your project
  • jflex-unicode-plugin the JFlex unicode maven plugin, used for compiling JFlex
  • testsuite the regression test suite for JFlex,
  • third_party third-party librairies used by examples of the Bazel build system

Build from source

Build with Bazel

JFlex can be built with Bazel. Migration to Bazel is still work in progress, concerning the test suite, for instance.

You need Bazel.

bazel build //jflex:jflex_bin

This builds bazel-bin/jflex/jflex_bin, that you can use

bazel-bin/jflex/jflex_bin --info

Or:

bazel run //jflex:jflex_bin -- --info

Build uberjar (aka fatjar aka deploy jar)

bazel build jflex/jflex_bin_deploy.jar

Continuous integration is done with Cirrus CI.

Build with Maven

You need JDK 8 or later.

./mvnw install

This generates jflex/target/jflex-full-1.9.0-SNAPSHOT.jar that you can use, e.g.

java -jar jflex-full-1.9.0-SNAPSHOT.jar --info

Continuous Integration is made with Travis.

de.jflex

JFlex

The fast scanner generator for Java

Versions

Version
1.8.2
1.8.1
1.8.0
1.7.0
1.6.1
1.6.0
1.5.1
1.5.0