ruleExists function
Implementation
bool ruleExists(String fileContents, String rule) {
bool result = false;
List<String> fileC = fileContents.split('\n');
for (int i = 0; i < fileC.length; i++) {
String line = fileC[i];
List<String> ruleTup = getMatches(line);
if (ruleTup.length == 2) {
if (ruleTup[0] == rule) {
result = true;
} else {}
} else {}
}
return result;
}