Review

6

/mubench/mubench.pipeline/../checkouts/closure/319/original-src/com/google/javascript/jscomp/LightweightMessageFormatter.java

formatRegion(Region)

class LightweightMessageFormatter.LineNumberingFormatter {
    public String formatRegion(Region region) {
      if (region == null) {
        return null;
      }
      String code = region.getSourceExcerpt();
      if (code.length() == 0) {
        return null;
      }

      // max length of the number display
      int numberLength = Integer.toString(region.getEndingLineNumber())
          .length();

      // formatting
      StringBuilder builder = new StringBuilder(code.length() * 2);
      int start = 0;
      int end = code.indexOf('\n', start);
      int lineNumber = region.getBeginningLineNumber();
      while (start >= 0) {
        // line extraction
        String line;
        if (end < 0) {
          line = code.substring(start);
          if (line.length() == 0) {
            return builder.substring(0, builder.length() - 1);
          }
        } else {
          line = code.substring(start, end);
        }
        builder.append("  ");

        // nice spaces for the line number
        int spaces = numberLength - Integer.toString(lineNumber).length();
        builder.append(Strings.repeat(" ", spaces));
        builder.append(lineNumber);
        builder.append("| ");

        // end & update
        if (end < 0) {
          builder.append(line);
          start = -1;
        } else {
          builder.append(line);
          builder.append('\n');
          start = end + 1;
          end = code.indexOf('\n', start);
          lineNumber++;
        }
      }
      return builder.toString();
    }

}