Bool

Boolean expression evaluator

License	MIT License
GroupId	info.cukes
ArtifactId	bool
Last Version	1.0.20
Release Date	Jan 20, 2014
Type	jar
Description	Bool Boolean expression evaluator
Project URL	https://github.com/cucumber/bool

Download bool

Filename	Size
bool-1.0.20.pom
bool-1.0.20.jar	19 KB
bool-1.0.20-sources.jar	15 KB
bool-1.0.20-javadoc.jar	64 KB

How to add to project

Apache Maven

<!-- https://jarcasting.com/artifacts/info.cukes/bool/ -->
<dependency>
    <groupId>info.cukes</groupId>
    <artifactId>bool</artifactId>
    <version>1.0.20</version>
</dependency>

Gradle Groovy

// https://jarcasting.com/artifacts/info.cukes/bool/
implementation 'info.cukes:bool:1.0.20'

Gradle Kotlin

// https://jarcasting.com/artifacts/info.cukes/bool/
implementation ("info.cukes:bool:1.0.20")

Apache Buildr

'info.cukes:bool:jar:1.0.20'

Apache Ivy

<dependency org="info.cukes" name="bool" rev="1.0.20">
  <artifact name="bool" type="jar" />
</dependency>

Groovy Grape

@Grapes(
@Grab(group='info.cukes', module='bool', version='1.0.20')
)

Scala SBT

libraryDependencies += "info.cukes" % "bool" % "1.0.20"

Leiningen

[info.cukes/bool "1.0.20"]

Dependencies

test (1)

Group / Artifact	Type	Version
junit : junit	jar	4.11

Project Modules

There are no modules declared in this project.

bool

This is a cross-platform library for parsing boolean arithmetic expressions like a && b && (!c || !d) and evaluating them by assigning values to the variables.

Boolean expressions are parsed into an abstract syntax tree (AST).

This is done with a generated lexer and parser. The generators used are:

• Java: Ragel and Bison
• Ruby: (C extension): Ragel and Bison
• JRuby: Ragel and Bison
• JavaScript: jison-lex and Jison

This choice of generators makes it easy to port the implementation to other languages since they are ported to most programming languages.

Evaluation of the boolean expressions is done by traversing the AST with a visitor. (This is obviously overkill for something as simple as boolean expressions, keep reading to understand why).

Supported platforms are Ruby, JRuby, Java and JavaScript. More platforms like Python, PHP and .NET may be added later.

The Ruby gem uses a C extension (for speed) and the JRuby gem uses a Java extension (also for speed). Support for e.g. Python could be added easily by using the same C code as the Ruby gem. Java programs (or any other JVM-based program such as Scala or Clojure) can also use the Java library as-is.

Why?

The purpose of this library is twofold.

First, it serves as a simple example of how to build a custom interpreted language with a fast lexer/parser that builds a visitor-traversable AST, and that runs on many different platforms. People who want to build a bigger cross-platform language could leverage the structure and build files in this project. For example, the Gherkin 3.0 project will use this project as a template.

Second, this project will be used by Cucumber to evaluate tag expressions in a more elegant way.

Building

See CONTRIBUTING.md

Cucumber

Cucumber Open

Versions

Version
1.0.20 Jan 20, 2014
1.0.19 Aug 27, 2013
1.0.18 Aug 20, 2013
1.0.16 Apr 15, 2013
1.0.15 Apr 14, 2013
1.0.14 Mar 16, 2013
1.0.11 Feb 14, 2013
1.0.10 Feb 14, 2013
1.0.9 Feb 14, 2013
1.0.8 Feb 14, 2013
1.0.6 Feb 13, 2013
1.0.5 Feb 13, 2013
1.0.3 Feb 11, 2013
1.0.0 Feb 11, 2013