Serious programmers have always understood the value of a good cross-reference program, but with today's large, modular applications, much more is often necessary. XREF is a sophisticated cross-reference utility program that provides comprehensive documentation about an entire application. Unlike other cross-reference programs you may have seen that merely list each variable, XREF provides a wealth of useful reports that show exactly what is going on in your programs. Of course, XREF does a terrific job of listing variables in alphabetical order, so you can quickly spot any that are misspelled. But XREF goes far beyond that - it is the very best way to completely document your entire program. XREF is also ideal when you need to understand and work on someone else's programs, or update a program you wrote long ago.

XREF is extremely easy to use, and all of its operations are handled using pull-down menus and dialog boxes. This avoids having to memorize confusing commands or option switches. Most aspect of the program, such as report and printer settings, are user-definable, and the current setup may be saved to individual configuration files or to a system default configuration file. Many useful reports can be created, and they may be sent to a printer, a disk file, or viewed on-screen in a unique browse mode that lets you scroll the report vertically and horizontally. The report browsing feature is particularly valuable because the reports are available immediately for viewing without tying up your printer or wasting paper.

XREF examines all of the files that comprise your application, including those modules that are external to your main BASIC program file. Further, all Include files are read and processed. XREF understands COMMON and SHARED, as well as DIM AS, DEFINT, and all the other DEFtype statements. XREF is compatible with all versions of Microsoft BASIC for DOS, including GW-BASIC and BASICA, so it is ideal when you are converting a large program from those earlier dialects. Because XREF processes your program in a single pass, it is also extremely fast. XREF reads all of the source code that is associated with your program and then parses the individual program objects into tables. Object types include key words, DEF FN functions, SUB and FUNCTION procedures, line labels, and CONST constants. Other object types include simple numeric, string, and TYPE variables, as well as Static and Dynamic numeric, string, and TYPE arrays. After all of the source code has been read, XREF creates a database of the object tables for further processing. This lets you run other reports later on, without having to process the source files again. XREF offers many different perspectives on a program, by providing the following information:

Generates source listings with headers and physical line numbers. Line numbers can be listed as relative to the beginning of procedures, like the BASIC editor, or relative to the start of the source file.

Complete control over how programs are listed. Each procedure can start on a new page if you prefer. XREF also prints a Table of Contents for the entire listing, showing the starting page number for each procedure.

Creates Call Tree diagrams. The XREF Call Tree report shows the interrelationships between all of the procedures used in your application. The report may be organized either alphabetically, or in logical (order of occurrence) order. This helps you to more easily visualize the overall structure of your program.

Generates an Object Summary Report. The Object Summary report lists all of your program objects, such as BASIC key words, SUB and FUNCTION procedures, simple and TYPE variables, and both Static and Dynamic arrays. Objects are grouped by their type and displayed alphabetically. Each object is listed showing where it was defined and how many times it was used. The BASIC Key Word report shows which statements you have used, flagging those that bring in the BASIC floating point library, thus increasing the size of your .EXE program file. This report also shows which key words are not supported by our P.D.Q. library. The Object Summary report also identifies variables referenced only once, as well as procedures that are declared or defined but never used.

Provides complete information about each variable. Program elements can be listed by procedure along with their type, so you can easily see which variables are passed as parameters and which are Static, Dynamic, and Shared. If the same element is used in different modules (such as COMMON variables), this is listed as well. These features let you know immediately which variables are affected by procedures and which are private.

Understands all BASIC source listing metacommands. Although Microsoft no longer documents the various metacommands in their manuals, all current versions of the compiler recognize them. The XREF owner's manual provides a complete listing of all useful options, and the program honors them as it displays the various reports. This lets you define titles and subtitles for each page, turn the source listing on and off, and so forth.

Extracts quoted strings for spell checking. A special utility is provided to extract all quoted strings and remarks and write them to a file, so you can proof and spell-check them using any word processor. A companion utility merges the corrected text back into your program files, with the original spacing intact. This feature also helps if you need to translate all of a program's text to a foreign language.

Removes unused line numbers from old programs. Many programmers don't realize that unnecessary line numbers can slow down the BASIC compiler and impinge on its working memory. Line numbers can also make a program larger and run more slowly when certain compiler options are used. A separate utility is included to remove all line numbers from your source files that are not actually needed.

Simplifies modularization. A unique report shows all of the variables that are referenced both within a given range of source lines and also referenced outside that range. If you need to convert a section of code (such as a GOSUB routine) into a subprogram or function, this report shows you which variables must be passed or shared.