Line Continuation for Complex XFDs

$XFD directives may be continued onto multiple lines by specifying a single character backslash (\) as the last non-blank character on a line. For example:

$XFD WHEN (var1 = "abc" and var2 = "def"    \
$XFD       and (var3 = "ghi" or var4 = "jkl"))  \
$XFD       or var5 != "xyz"

Line Continuation Rules

  • $XFD directives are continued via a backslash as the last non-blank character on the line.
  • Continued lines begin with $XFD just like the first directive line (with the dollar sign in the indicator column).
  • The final continuation line omits the trailing backslash.
  • "The overall combined directive is a concatenation of all of the continuation lines.
  • The next character after the blank that follows $XFD is the next character of the directive. That character logically replaces the backslash on the previous line.
  • There is no limit on the number of continuation lines other than the limit on total program source lines, and the overall size of the continued directive is limited only by available memory. But it is highly unlikely that one XFD directive would ever need to exceed a few dozen lines or a few thousand characters.
  • In standard ANSI source format the contents of columns 73-80 are ignored, the continuation backslash must appear in Area B (columns 12-72).
  • Backslashes within data (literals) do not cause a problem because they are inside quoted strings (and cannot be the last non-blank character on the line).
  • In-line comments ("*>") are not allowed on continued XFD directive lines.
  • A new error message is generated for a syntax error within continued XFD directive lines and the erroneous continuation lines scanned up to that point are ignored. Possible syntax errors include placing a source line other than a comment line within an intended sequence of continued XFD directive lines, or omitting the final continuation line (the line that begins with $XFD and does not end with a trailing backslash). Other errors are possible when the directive itself is scanned and processed.