LineColTracker.java

package folioxml.core;

/**
 * Implements unicode-compliant line number and column counting. Since some line terminators span multiple characters, this requires state tracking.
 * Lines and columns are 0-based. Used by TokenReaderBase to parse completed matches.
 *
 * @author nathanael
 */
public class LineColTracker {

    public LineColTracker() {

    }

    private long _line = 0;
    private long _col = 0;
    private long _char = 0;

    public TokenInfo getTokenInfo() {
        TokenInfo t = new TokenInfo();
        t.col = col();
        t.line = line();
        t.charIndex = chars();
        return t;

    }

    /**
     * The index of the current line. 0-based
     *
     * @return
     */
    public long line() {
        return _line;
    }

    public LineColTracker line(long newValue) {
        _line = newValue;
        return this;
    }

    /**
     * The character index from the last line terminator. First character on a line = 0
     *
     * @return
     */
    public long col() {
        return _col;
    }

    public LineColTracker col(long newValue) {
        _col = newValue;
        return this;
    }

    /**
     * Character index from the beginning of the file, including line terminators. 0-based
     *
     * @return
     */
    public long chars() {
        return _char;
    }

    public LineColTracker chars(long newValue) {
        _char = newValue;
        return this;
    }

    private boolean skipLF = false;

    public LineColTracker add(CharSequence cs) {
        return add(cs, 0, cs.length());
    }

    public LineColTracker add(CharSequence text, int startIndex, int endIndex) {
        char c;
        for (int i = startIndex; i < endIndex; i++) {
            c = text.charAt(i);
            _char++; //always increment this guy

            //Skip the LF: ON CR-LF we count the CR and skip the immediately subsequent LF
            if (c == '\n' && skipLF) {
                skipLF = false;
                continue;
            }

            skipLF = (c == '\r'); //If it's a CR, skip the following LF

            //Check all unicode spec newline chars.
            if (c == '\r' || c == '\n' || c == '\u0085' || c == '\u000c' || c == '\u2028' || c == '\u2029') {
                _line++;
                _col = 0;
            } else {
                _col++;
            }
        }
        return this;
    }


}