Parser leftParser = new AlParser(leftReader);
Parser rightParser = new AlParser(rightReader);
int width = createInt(commandLine, "width", PresentationFormatter.DEFAULT_WIDTH);
Formatter formatter = new PresentationFormatter(getErr(), width);
boolean showDiff = commandLine.hasOption('d');
List<Alignment> leftAlignmentList = leftParser.parse();
List<Alignment> rightAlignmentList = rightParser.parse();
Diff diff = compare(leftAlignmentList, rightAlignmentList);
if (showDiff) {
Iterator<List<Alignment>> leftIterator = diff.getLeftGroupList().iterator();
Iterator<List<Alignment>> rightIterator = diff.getRightGroupList().iterator();
while (leftIterator.hasNext()) {
List<Alignment> leftGroup = leftIterator.next();
List<Alignment> rightGroup = rightIterator.next();
getErr().println("< left alignments");
getErr().println();
formatter.format(leftGroup);
getErr().println();
getErr().println();
getErr().println("> right alignments");
getErr().println();
formatter.format(rightGroup);
getErr().println();
getErr().println();
getErr().println();