This is the continuation to my previous blog post on Legacy application modernization using AI & ML.

From my previous blog post – “Legacy RPG and CLP applications can be modernized using AI-powered tools that analyze and refactor code into optimized, modular structures. For example, AI can scan RPG III or old cycle-based programs and suggest converting fixed-format code into modern free-format RPG for better readability and maintainability.”

Let us explore how AI tools can help us in this process.

• AI powered code analysis uses machine learning and natural language processing techniques to scan source code and help us detect issues like:

·         Bad coding practices (like hardcoding)

·         Performance bottlenecks

·         Unused or duplicate code

For example, consider this old RPG code with hardcoded values:

C     READ FILE1        

C     IF FIELD1 = 'X'  

C        CALL 'OLDPROC'  

C     ENDIF             

Which can be refactored using Free RPG as:

Dcl-S fieldValue Char(1);

READ FILE1;

fieldValue = FIELD1;

Select;

   When fieldValue = 'X';

      Exsr NewProcedure;

EndSl;

•  AI powered refactoring automatically improves code efficiency without changing the logic. Consider the below RPG III fixed format code:

C     Z-ADD     0           TOTAL     10 0

C     DO        100         I

C     Z-ADD     I           VALUE     10 0

C     ADD       VALUE       TOTAL

C     ENDDO

C     SETON                   LR

which can be refactored using Free RPG as:

ctl-opt dftactgrp(*no) actgrp(*caller);

//Variable declaration using dcl-s

for i = 1 to 100;

    total += i;

endfor;

*inlr = *on;

The AI tool identified redundant Z-ADD operations and an unnecessary temporary variable VALUE in the previous code. It optimized these elements using a concise code snippet, replacing the legacy style code with modern RPG. This enhancement improves both readability and maintainability.

• AI powered code transformation - One of the main challenges is modernizing legacy RPG code int any new programming languages (like Python). AI-powered tools can automatically translate RPG into Python. For example, lets take the same RPG III code:

C     Z-ADD     0           TOTAL     10 0

C     DO        100         I

C     Z-ADD     I           VALUE     10 0

C     ADD       VALUE       TOTAL

C     ENDDO

C     SETON                   LR

which can be converted into optimized Python code:

# Efficient Python version

total = range (1, 101))

print(f"Total: {total}")

In the next post, we will discuss examples on AI-driven data migration and cleansing processes.