This repository contains the code and framework developed as part of a thesis project aimed at comparing open-source Java libraries for parsing and evaluating mathematical expressions. The project focuses on analyzing the capabilities, strengths, and limitations of these libraries.

The primary objective of this project is not to create a new parsing tool, but to develop a comparison framework that evaluates existing libraries based on key attributes. This framework serves as a decision-making tool to help others select the most suitable library for their needs.

The main goals of the project are:

1. Provide a generic overview of parsing and evaluating mathematical expressions.
2. Analyze at least three existing open-source libraries for mathematical expression parsing in Java.
3. Identify evaluation criteria to compare these libraries consistently.
4. Develop a comparison framework in Java to test and evaluate libraries under different scenarios.
5. Deliver practical recommendations on which library to use under specific boundary conditions.

The project evaluates at least three popular Java libraries for parsing and evaluating mathematical expressions. Examples of libraries studied include:

• exp4j
• EvalEx
• Expr4j
• JavaMathExpressionParser
• Paralithic
• Javaluator

The framework evaluates libraries based on the following attributes:

• Performance: Measures how efficiently a library parses and evaluates expressions, particularly for large and complex formulas.
• Usability: Assesses the simplicity of integration and ease of use for developers.
• Extensibility: Evaluates how well the library supports custom operators, functions, and additional features.
• Syntax Support: Tests the library’s ability to handle various mathematical constructs, including functions, constants, and operators.

The framework provides recommendations tailored to specific scenarios, such as:

• Performance-Oriented Tasks: Selecting the fastest or most memory efficient library for real-time evaluations.
• Customization Needs: Identifying libraries that support user-defined operators or functions.
• Correctness of Evaluation: Finding the most versatile libraries, that comply with standard operator precedence and return accurate results.

1. External Libraries:
   This project uses three external libraries that were not imported through Maven, their .jar files are included in the lib folder.

   • You will need to manually add these .jar files to your project’s classpath to run the application.
     • In IntelliJ IDEA:
       1. Go to File > Project Structure > Libraries.
       2. Click + and add the .jar files from the lib folder.
     • In Eclipse:
       1. Right-click the project in the Package Explorer.
       2. Navigate to Build Path > Add External Archives, and select the .jar files.

2. Configuring the Program:
   The program execution is controlled from the Main.java file. Here, you can:

   • Select Tests: Comment out any unwanted test cases or parsing libraries that you do not wish to execute.
   • Example:

     // Comment out the unwanted tests
     orchestrator.addTest(new SpeedTest());
     orchestrator.addTest(new DataTypeTest());

3. Customizing Output:
   The output behavior can be configured using the OutputHandler class.

   • Modify the line OutputHandler.setConfig(true, true, true); in Main.java to enable or disable specific output methods:
     • First Argument: Enable/disable console output.
     • Second Argument: Enable/disable file logging.
     • Third Argument: Enable/disable data reporting filtered by test.

src/
├── main/
│   ├── java/
│   │   └── org.parser.evaluator/
│   │       ├── strategies/                     # Library-specific parsers and evaluators
│   │       │   ├── EvalEx/
│   │       │   │   ├── EvalEx.java
│   │       │   │   ├── FactorialFunction.java
│   │       │   │   └── FactorialOperator.java
│   │       │   ├── Exp4j/
│   │       │   │   └── Exp4j.java
│   │       │   ├── Expr4j/
│   │       │   │   └── Expr4j.java
│   │       │   ├── JavaMathExpressionParser/
│   │       │   │   └── JavaMathExpressionParser.java
│   │       │   ├── Paralithic/
│   │       │   │   └── Paralithic.java
│   │       │   └── IParser.java                # Interface for parser strategies
│   │       ├── testers/                        # Testing framework
│   │       │   ├── extensibility/              # Tests for extensibility
│   │       │   │   ├── ExtensibilityTest.java
│   │       │   │   └── VariableTest.java
│   │       │   ├── generator/                  # Expression generation logic
│   │       │   │   ├── ExpressionGenerator.java
│   │       │   │   └── IExpressionGenerator.java
│   │       │   ├── mathematical/               # Tests for mathematical correctness
│   │       │   │   ├── DataTypeTest.java
│   │       │   │   └── MathExpressionTest.java
│   │       │   ├── performance/                # Performance testing
│   │       │   │   ├── MemoryTest.java
│   │       │   │   └── SpeedTest.java
│   │       │   └── Test.java                   # Base test class
│   │       ├── util/                           # Utility classes
│   │       │   ├── log/
│   │       │   │   ├── report/                 # Reporting utilities
│   │       │   │   │   ├── GeneralRecorder.java
│   │       │   │   │   ├── LogContext.java
│   │       │   │   │   ├── TableReporter.java
│   │       │   │   │   └── OutputHandler.java
│   │       │   └── Orchestrator.java           # Orchestrates test runs
│   │       └── Main.java                       # Entry point for running tests
├── resources/                                  # Configuration files or sample data
└── test/                                       # Unit tests
    └── java/
        └── ExpressionGeneratorTest.java        # Test for expression generator

Contributions to improve the framework, expand comparisons, or add new libraries are welcome. Please open an issue or submit a pull request.

For questions or feedback, feel free to reach out:
Lili Sebők – seboklili1@gmail.com