In the Protect10 and Protect11 conferences, I gave a presentation about Financial Application Modeling techniques. As a precursor to these, I talked about the issues in writing FlexConnectors for complex Financial Application transaction files, and a simple tool I had developed to help tackle this problem.
The tool is an Excel sheet which can be used, one transaction type at a time, to copy/paste the application's data dictionary entries into a worksheet, and have the FlexConnector token/type declarations and regex generated out of this, to which other elements (eg. field mappings) are then added. For a variable fixed-width legacy financial app (for which this is designed), it can turn an error-prone weeks-long task into a day or two for initial development and testing.
As promised in the P11 conference, the workbook is attached here. It's very simple - just string functions and lookups - but provides an approach which could be adapted for other similar (fixed-width, complex variable multi-field) applications. It is intentionally 'interactive' - no VB scripts - so it's easy to change and troubleshoot. Ease of use/understanding/adaptation is also why this is in Excel rather than Perl or Nawk, for example.
I've added explanatory notes to try to document through the workbook. I've also added resulting parser files as objects on the last sheet. Note that while based on a production system, the workbook/parser has been substantially for the presentation, and the modified versions have not been tested end-to-end. In the true spirit of this collaborative workplace, please feel free to find bugs and comment below, or fix and repost.
The P10 recording (by Paul Brettle) is here. The P11 recording/full presentation will be posted according to the release schedule for P11 attendees/non-attendees, in the relevant forum.