* The general systax is:
* [!][o][odd][e][even]start-end
*
* You can have multiple ranges separated by commas ','. The '!' modifier removes the
* range from what is already selected. The range changes are incremental, that is,
* numbers are added or deleted as the range appears. The start or the end, but not both, can be ommited.
*/
public class SequenceList {
protected static final int COMMA = 1;
protected static final int MINUS = 2;
protected static final int NOT = 3;
protected static final int TEXT = 4;
protected static final int NUMBER = 5;
protected static final int END = 6;
protected static final char EOT = '\uffff';
private static final int FIRST = 0;
private static final int DIGIT = 1;
private static final int OTHER = 2;
private static final int DIGIT2 = 3;
private static final String NOT_OTHER = "-,!0123456789";
protected char text[];
protected int ptr;
protected int number;
protected String other;
protected int low;
protected int high;
protected boolean odd;
protected boolean even;
protected boolean inverse;
protected SequenceList(String range) {
ptr = 0;
text = range.toCharArray();
}
protected char nextChar() {
while (true) {
if (ptr >= text.length)
return EOT;
char c = text[ptr++];
if (c > ' ')
return c;
}
}
protected void putBack() {
--ptr;
if (ptr < 0)
ptr = 0;
}
protected int getType() {
StringBuffer buf = new StringBuffer();
int state = FIRST;
while (true) {
char c = nextChar();
if (c == EOT) {
if (state == DIGIT) {
number = Integer.parseInt(other = buf.toString());
return NUMBER;
}
else if (state == OTHER) {
other = buf.toString().toLowerCase();
return TEXT;
}
return END;
}
switch (state) {
case FIRST:
switch (c) {
case '!':
return NOT;
case '-':
return MINUS;
case ',':
return COMMA;
}
buf.append(c);
if (c >= '0' && c <= '9')
state = DIGIT;
else
state = OTHER;
break;
case DIGIT:
if (c >= '0' && c <= '9')
buf.append(c);
else {
putBack();
number = Integer.parseInt(other = buf.toString());
return NUMBER;
}
break;
case OTHER:
if (NOT_OTHER.indexOf(c) < 0)
buf.append(c);
else {
putBack();
other = buf.toString().toLowerCase();
return TEXT;
}
break;
}
}
}
private void otherProc() {
if (other.equals("odd") || other.equals("o")) {
odd = true;
even = false;
}
else if (other.equals("even") || other.equals("e")) {
odd = false;
even = true;
}
}
protected boolean getAttributes() {
low = -1;
high = -1;
odd = even = inverse = false;
int state = OTHER;
while (true) {
int type = getType();
if (type == END || type == COMMA) {
if (state == DIGIT)
high = low;
return (type == END);
}
switch (state) {
case OTHER:
switch (type) {
case NOT:
inverse = true;
break;
case MINUS:
state = DIGIT2;
break;
default:
if (type == NUMBER) {
low = number;
state = DIGIT;
}
else
otherProc();
break;
}
break;
case DIGIT:
switch (type) {
case NOT:
inverse = true;
state = OTHER;
high = low;
break;
case MINUS:
state = DIGIT2;
break;
default:
high = low;
state = OTHER;
otherProc();
break;
}
break;
case DIGIT2:
switch (type) {
case NOT:
inverse = true;
state = OTHER;
break;
case MINUS:
break;
case NUMBER:
high = number;
state = OTHER;
break;
default:
state = OTHER;
otherProc();
break;
}
break;
}
}
}
/**
* Generates a list of numbers from a string.
* @param ranges the comma separated ranges
* @param maxNumber the maximum number in the range
* @return a list with the numbers as Integer
*/
public static List expand(String ranges, int maxNumber) {
SequenceList parse = new SequenceList(ranges);
LinkedList list = new LinkedList();
boolean sair = false;
while (!sair) {
sair = parse.getAttributes();
if (parse.low == -1 && parse.high == -1 && !parse.even && !parse.odd)
continue;
if (parse.low < 1)
parse.low = 1;
if (parse.high < 1 || parse.high > maxNumber)
parse.high = maxNumber;
if (parse.low > maxNumber)
parse.low = maxNumber;
//System.out.println("low="+parse.low+",high="+parse.high+",odd="+parse.odd+",even="+parse.even+",inverse="+parse.inverse);
int inc = 1;
if (parse.inverse) {
if (parse.low > parse.high) {
int t = parse.low;
parse.low = parse.high;
parse.high = t;
}
for (ListIterator it = list.listIterator(); it.hasNext();) {
int n = ((Integer)it.next()).intValue();
if (parse.even && (n & 1) == 1)
continue;
if (parse.odd && (n & 1) == 0)
continue;
if (n >= parse.low && n <= parse.high)
it.remove();
}
}
else {
if (parse.low > parse.high) {
inc = -1;
if (parse.odd || parse.even) {
--inc;
if (parse.even)
parse.low &= ~1;
else
parse.low -= ((parse.low & 1) == 1 ? 0 : 1);
}
for (int k = parse.low; k >= parse.high; k += inc)
list.add(new Integer(k));
}
else {
if (parse.odd || parse.even) {
++inc;
if (parse.odd)
parse.low |= 1;
else
parse.low += ((parse.low & 1) == 1 ? 1 : 0);
}
for (int k = parse.low; k <= parse.high; k += inc) {
list.add(new Integer(k));
}
}
}
// for (int k = 0; k < list.size(); ++k)
// System.out.print(((Integer)list.get(k)).intValue() + ",");
// System.out.println();
}
return list;
}
}