Moving to Free-Format in RPG IV via WDSC

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I found an interesting feature in IBM's WDSC that provides a context menu (right-click) option that converts traditional RPG IV to free-format. It mostly works, but it avoids a few opcodes, such as ALLOC, MOVE and MOVEL—inserting /FREE and /END-FREE between these instructions—making for some ugly code.

That aside, the ability to easily convert from traditional RPG IV to free-format is pretty cool. I just wish it were more configurable. It puts the code in the far left column, but I'd like to insert about four or five positions. Also, I prefer lowercase /free and /end-free statements, but it inserts only /FREE and /END-FREE.

Those are just nits and not very important in the grand scheme of things. But the fact that free-format doesn't support the MOVE and MOVEL opcodes is annoying, and I'm not certain why WDSC won't convert ALLOC to a %ALLOC built-in function.

If you're like me and you code in a contemporary way, using IF and EVAL opcodes with extended Factor 2, the WDSC "Convert selection to free-format" does a fine job of moving things into the /free specification. For example, if you have an RPG III program that was converted to RPG IV using the IBM CVTRPGSRC command and you select a traditional section of code to convert, it produces good-enough results, but it doesn't magically transform the code, as follows:

     C                   Z-ADD     0             X                 3 0
     C                   DO        100           X
     C                   MOVE      CUST          SAVNO
     C     DMCUST        CHAIN     CUSTMAST       71
     C     *IN71         IFEQ      *OFF
     C                   MOVE      DMCST         CSTNAM
     C                   MOVE      DMADR1        CSTAD1
     C                   MOVE      DMCITY        CSTCTY
     C                   Z-ADD     DMSALES       CSTSLS
     C                   Z-ADD     DMCUST        CSTNBR
     C                   WRITE     CUSTREC
     C                   endIf

The results from WDSC's "Convert selection to free-format" are as follows:

     C                   Z-ADD     0             X                 3 0
     C                   DO        100           X
     C                   MOVE      CUST          SAVNO
      /FREE
         CHAIN DMCUST CUSTMAST;
         *IN71 = NOT %FOUND;
         IF *IN71 = *OFF;
      /END-FREE
     C                   MOVE      DMCST         CSTNAM
     C                   MOVE      DMADR1        CSTAD1
     C                   MOVE      DMCITY        CSTCTY
     C                   Z-ADD     DMSALES       CSTSLS
     C                   Z-ADD     DMCUST        CSTNBR
      /FREE
           WRITE CUSTREC;
         endIf;
       endDo;
      /END-FREE    

As you can see, it's not pretty, and it requires a lot of hand-coding to complete the move to free-format.

There are third-party packages available, and quite frankly, the routine I wrote for my own CodeStudio Windows-based RPG editor did a much better job, but I no longer distribute or support that tool.

The road to /free requires that you have a few tools in your arsenal. Assuming you're starting with an RPG III program (if not, simply bypass step 1), the following tools are required:

  1. IBM's CVTRPGSRC command, included with your RPG IV compiler
  2. A third-party utility to convert the RPG IV code to real RPG IV syntax, such as Linoma Software's RPG Wizard (part of their RPG Toolbox package) or BVS Tools CVTILERPG command
  3. IBM's WDSC "Convert selection to free-format" context menu (right-click)

Item 2 is any third-party tool that converts RPG IV that was created using CVTRPGSRC to modern RPG IV—that is, from MOVE, Z-ADD, MOVEL, IFEQ, etc. to corresponding EVAL and IF statements.

While this may seem like an annoying or lengthy path just to get to free-format, it really isn't. If you're moving an RPG III program to RPG IV, make these steps part of your conversion workflow.

The Linoma RPG Wizard can streamline the workflow. It converts RPG III to RPG IV and then runs it through Linoma's own RPG IV to /FREE utility—and does so seamlessly.

Why Move to /FREE

No one took longer to get to /free than I. In fact, I still prefer to write in native RPG IV (which some people refer to as "hybrid" RPG IV). But as I use more and more subprocedure-oriented code, the additional space of the free-format syntax is beneficial. Certainly, there are some "bad things" about free-format RPG IV, but they're more annoyances than roadblocks.

Whether you code completely in free-format or only write in native RPG IV, the productivity of the RPG IV language is much greater than traditional RPG III-style code.

The road to /free is paved with minor obstacles, but you can get where you need to go if you just overlook those barriers.

Bob Cozzi is author of the best-selling The Modern RPG IV Language, Fourth Edition as well as RPG TNT: 101 Dynamite Tips 'n Techniques with RPG IV and is host of the i5 Podcast Network, which provides free video and audio podcasts to the i5 community. You can also see him in person at RPG World in May 2007.

BOB COZZI

Bob Cozzi is a programmer/consultant, writer/author, and software developer. His popular RPG xTools add-on subprocedure library for RPG IV is fast becoming a standard with RPG developers. His book The Modern RPG Language has been the most widely used RPG programming book for more than a decade. He, along with others, speaks at and produces the highly popular RPG World conference for RPG programmers.


MC Press books written by Robert Cozzi available now on the MC Press Bookstore.

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The Modern RPG IV Language The Modern RPG IV Language
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