Fetch the current rule number that code is being executed in.
returnedString = variableType("$rulenum")
returnedString - type: integer
variableType - type: G
Current rule number within the current pass of the analyzer.
With $passnum, yields the pass and rule number. $rulenum is unique in the current pass, but not across the passes of the analyzer. In each pass, rule numbering is 1, 2, 3 ...
# Print current pass number and rule number.
"output.txt" << G("$passnum") << ", " << G("$rulenum") << "\n";
_xNIL <- _clause @@
When this rule matches, output.txt contains lines such as
$passnum, Special Variables