My experience as an AS/400 systems programmer, spanning almost half a century, is inextricably linked to the evolution of the RPG language. More than just a job, it has been a true adventure, a journey of continuous discovery and adaptation. I have had the privilege of witnessing the birth and growth of this language, understanding its nuances, and passing on its secrets to countless programmers.
Deep Roots: RPG in Fixed Format, an Exercise in Precision
I still vividly recall my first encounters with RPG, a language conceived in the 1960s to replicate the functionality of punched card machines, the cornerstones of data processing at the time. The fixed format, with its rigidity and ironclad rules, was the absolute standard. Each instruction, each variable, each parameter had to occupy a precise position within the lines of code. Precision was an indispensable virtue, and the slightest error could compromise the entire program.
In those years, my role was that of the "master": the repository of knowledge, the one who explained the rules of the game, illustrated the specifics of the language, and guided students through the intricacies of the SEU (Source Entry Utility), the text editor par excellence. The teaching method was structured and rigorous: it started from the basics, addressed the most complex aspects, and practiced syntax until achieving almost automatic mastery. The students, with commitment and dedication, absorbed the notions, confronted the difficulties, and learned to solve problems. It was an "analog" learning approach, based on practice and direct experience.
Maturity: RPG IV, a Hesitant but Significant Evolution
With the advent of AS/400, RPG took a step forward, evolving into RPG IV. This new version introduced more advanced features, such as subroutines, data structures, and external file management. However, the fixed format remained predominant, although the first signs of greater flexibility and a more intuitive syntax were glimpsed.
RPG IV represented a significant evolution, but not a revolution. The language still retained many of its original characteristics, and the transition was neither immediate nor painless. Many programmers, accustomed to the fixed format, struggled to adapt to the new features and more flexible syntax.
The Revolution: RPG Free Format and ILE, a New World of Possibilities
The real turning point came with the introduction of free format and the ILE (Integrated Language Environment). Free format represented a true liberation: the code became more readable, maintainable, and easier to understand. The syntax was simplified, and programming became more intuitive and less constrained.
The ILE environment, on the other hand, opened up a new world of possibilities: it allowed the integration of RPG modules with other programming languages, such as C, C++, and Java, creating more complex and sophisticated applications. ILE also introduced the concept of "service program," which are code modules that can be reused in different applications, reducing code duplication and simplifying maintenance.
The Teaching Crisis: When the "Master" Must Become a "Student"
It was here that my experience as a teacher underwent a profound transformation. I found myself facing a new generation of students, born in the digital age, accustomed to graphical interfaces, modern programming languages, and agile development methodologies. These students, although unfamiliar with the fixed format, possessed a wealth of skills and knowledge that I, despite my experience, could not ignore.
Teaching them RPG in fixed format with the SEU seemed an anachronistic, almost an imposition. It was like forcing them to use a hand-cranked calculator in the age of quantum computers. I realized that the problem was not the students, but my teaching approach. It was I who had to change, to question myself, and to embrace new technologies. I had to transform myself from "master" to "student," learning from my students and integrating their skills with my knowledge.
The Redemption: Modern RPG, a Bridge Between Tradition and Innovation
It was here that I discovered the beauty of RPG in free format and the power of the ILE environment. I realized that I could still convey the fundamental concepts of RPG, but using modern and intuitive development tools, such as Visual Studio Code with specific extensions or the Eclipse environment with the RDi (Rational Developer for i) plugin.
I learned to create a more dynamic and stimulating learning environment, in which students could experiment, innovate, and give free rein to their creativity. I discovered that the new generations of programmers can use their skills to program on IBM i, fully exploiting the potential of the system.
I began to integrate my experience with their knowledge, creating a "bridge" between tradition and innovation. I learned to value their skills, to encourage them to experiment, and to support them in their learning journey.
The Future: RPG, a Living and Continuously Evolving Language
My journey through the evolution of RPG has taught me that knowledge is a river in constant motion. We cannot remain anchored to the past, but we must be ready to adapt, to learn, and to grow.
RPG still has much to offer, and the new generations of programmers can help shape its future. Using modern tools, harnessing the power of IBM i, and embracing new technologies, we can create innovative and competitive applications, demonstrating that RPG is not a language of the past, but a valuable resource for the future.
Conclusions: RPG, a Heritage to Value
The secret is to never stop learning, experimenting, and sharing our passion for this language that, after so many years, continues to amaze and offer us new challenges. RPG is a heritage to value, a treasure to be guarded, and an opportunity to be exploited. With the right mindset, with the appropriate tools, and with the passion that distinguishes us, we can guarantee a bright future for this language that has marked the history of computer science and that continues to be a fundamental pillar of the IBM i world.