SuperC Option to Report Entire Record and Highlight Differences

Showing the full line by wrapping as necessary sounds sensible if practical, and that idea has already been on our requirements list for many years (at least since 2003, when customer requirement MR1125036351 was raised). It would of course need a new option for compatibility reasons.

There is a basic conceptual problem with marking old/new differences. A LINE comparison shows inserted and deleted lines, but apart from the case of reformatted text (where only spaces were changed, so the line still matched) SuperC does not specifically know which inserted line goes with which deleted line, only that a range of new lines replaced a range of old lines. It has no concept of how closely two lines match; they either match or they do not.

Even if SuperC made some arbitrary assumption to try to identify replaced lines (e.g. if old and new ranges contain same number of lines, assume replacements) it would also still be very difficult to mark differences, because in the general case the old and new comparison ranges do not have to be in the same columns, and blanks are normally ignored for matching purposes. It would at least be necessary to have separate markers for first difference positions in the old and new records.

Note that any non-trivial development work on SuperC currently requires a very strong justification. SuperC has historically acquired a lot of complex function, and is not easy to modify. We often find that customers are using it in ingenious ways which are not properly represented in our internal testing, so we are hesitant about making large changes because of the risk of breaking existing function. Even if we consider some enhancement potentially worth while, our skilled development resources are now more likely to be directed towards new areas (such as new hardware support and cloud support).

We accept that showing the full line would be a good idea if found to be practical in future, but reject the idea of marking differences as being too far outside the scope of the current design.

However, the fact that showing the full line has been on our customer requirements list since at least 2003 suggests that previous generations of the team did not consider the value of this item to be sufficient to justify the development resources. As a result of this RFE, I have added this to our current list of candidate items for future development, but this does not necessarily mean it will happen.

Regards, Jonathan Scott, for HLASM and Toolkit