Programming Language 4D

Overview

4D is a multi-purpose programming language and environment primarily designed for building database applications. It is recognized for its capability to integrate data management with business logic and user interface development, allowing developers to create enterprise-level applications efficiently. The name "4D" refers to the platform's four dimensions: data, development, deployment, and integration.

Historical Aspects

Creation and Early Development

4D was first released in the 1980s by the French company 4D S.A., which initially focused on providing a robust database management system. The language combined relational database capabilities with an object-oriented programming environment, a relatively unique feature at that time, allowing developers to work with data-driven applications seamlessly.

Evolution and Modernization

Over the years, 4D has undergone multiple updates, enhancing its capabilities and adapting to the changing technology landscape. In the late 1990s and early 2000s, the focus shifted to web integration and client-server architectures. The introduction of 4D WebStarter allowed developers to create web applications using the same code base.

Current State and Community

Today, 4D is actively maintained and has a dedicated user community. The platform has embraced modern programming practices and technologies, including cloud computing and mobile application development, placing it in competition with other systems designed for cross-platform deployment. Its current versions, such as 4D v18, increasingly embrace web technologies and provide tools for REST APIs, enhancing its relevance in contemporary software ecosystems.

Syntax Features

Object-Oriented Programming

4D supports object-oriented programming principles, allowing developers to create classes and objects. This encapsulation of data and behavior promotes better organization and reuse of code.

Class Person
    var name
    var age
End Class

var john = new Person
john.name := "John Doe"
john.age := 30

Built-In Database Commands

4D includes numerous built-in commands for database manipulation, making it easy to perform CRUD (Create, Read, Update, Delete) operations.

// Create a record
CREATE RECORD([Persons])
    [Persons]Name := "Alice"
    [Persons]Age := 25

Event-Driven Programming

4D is event-driven, making it easy to define actions that respond to user interactions, such as button clicks or menu selections.

// Button click event handler
On Click([Button])
    ALERT("Button clicked!")
End On Click

Native SQL Support

4D provides native SQL support, allowing developers to run SQL queries directly against the database.

var result := SQL("SELECT * FROM Persons WHERE Age > 20")

User Interface Design

Developers can create rich UIs directly within the 4D environment, utilizing a drag-and-drop interface for layout design.

// Example of adding a button to a form programmatically
Add Button([Form]; "Submit")

Scripting Capabilities

The 4D language includes powerful scripting capabilities that provide extensive control over the application flow.

If (john.age > 18)
    ALERT("Adult")
Else
    ALERT("Minor")
End If

Cross-Platform Compatibility

4D applications can run on both macOS and Windows, ensuring wide accessibility for end-users.

Web Application Development

4D supports the creation of web applications through integrated web server capabilities, utilizing HTML and JavaScript alongside 4D’s own language.

// Example of sending a web response
$httpResponse := "Welcome to 4D Web!"

REST API Development

5D allows developers to create REST APIs very easily, which is essential for modern application integration and interoperability.

// Define a REST endpoint
REST.POST("/api/persons"; PersonData)

Debugging Tools

4D provides integrated debugging tools that facilitate the identification and resolution of issues within the code.

Developer Tools and Runtimes

IDE

4D comes with an integrated development environment that combines code editing, database management, and UI design. It provides tools to design forms, reports, and manage data structures all within one interface.

Building Projects

Building a project in 4D involves creating and defining the structure of your database model, writing code for handling data and user interactions, and defining the UI. Once completed, you can run applications directly within the IDE or deploy them to the 4D server.

Compilers and Interpreters

4D uses an interpreter for its scripting language, allowing immediate execution of scripts without the need for a separate compilation step. This streamlined approach facilitates rapid application development.

Applications of 4D

4D is primarily used for developing database-centric applications in industries like finance, healthcare, education, and manufacturing. It is particularly favored for creating internal business applications, such as CRM, ERP, and inventory management systems. The platform's capability to handle large datasets and perform complex transactions makes it suitable for enterprise-level solutions.

Comparison to Relevant Languages

When comparing 4D to other programming languages, some notable points arise:

Source-to-Source Translation Tips

While source-to-source translation tools specific to 4D are limited, developers can utilize general transformation and adaptation strategies to port 4D applications to other languages by:

  1. Mapping database commands to equivalent SQL or ORM constructs in the target language.
  2. Translating 4D's event-driven code structure into equivalent event handling methods in languages like JavaScript or Python.
  3. Leveraging the object-oriented aspects of 4D for migration to languages that support classes and objects.

Existing source-to-source translation tools may not specifically target 4D, but general-purpose tools like transpilers can help convert code to more widely used languages, albeit with manual adjustments needed for business logic and database integration.