* You can construct an instance of SetOfIntegerSyntax by giving it in "string
* form." The string consists of zero or more comma-separated integer groups.
* Each integer group consists of either one integer, two integers separated by
* a hyphen (-), or two integers separated by a colon
* (:). Each integer consists of one or more decimal digits
* (0 through 9). Whitespace characters cannot
* appear within an integer but are otherwise ignored. For example:
* "", "1", "5-10", "1:2,
* 4".
*
* You can also construct an instance of SetOfIntegerSyntax by giving it in
* "array form." Array form consists of an array of zero or more integer groups
* where each integer group is a length-1 or length-2 array of
* ints; for example, int[0][],
* int[][]{{1}}, int[][]{{5,10}},
* int[][]{{1,2},{4}}.
*
* In both string form and array form, each successive integer group gives a * range of integers to be included in the set. The first integer in each group * gives the lower bound of the range; the second integer in each group gives * the upper bound of the range; if there is only one integer in the group, the * upper bound is the same as the lower bound. If the upper bound is less than * the lower bound, it denotes a null range (no values). If the upper bound is * equal to the lower bound, it denotes a range consisting of a single value. If * the upper bound is greater than the lower bound, it denotes a range * consisting of more than one value. The ranges may appear in any order and are * allowed to overlap. The union of all the ranges gives the set's contents. * Once a SetOfIntegerSyntax instance is constructed, its value is immutable. *
* The SetOfIntegerSyntax object's value is actually stored in "canonical
* array form." This is the same as array form, except there are no null ranges;
* the members of the set are represented in as few ranges as possible (i.e.,
* overlapping ranges are coalesced); the ranges appear in ascending order; and
* each range is always represented as a length-two array of ints
* in the form {lower bound, upper bound}. An empty set is represented as a
* zero-length array.
*
* Class SetOfIntegerSyntax has operations to return the set's members in
* canonical array form, to test whether a given integer is a member of the
* set, and to iterate through the members of the set.
*
* @author David Mendenhall
* @author Alan Kaminsky
*/
public abstract class SetOfIntegerSyntax implements Serializable, Cloneable {
private static final long serialVersionUID = 3666874174847632203L;
/**
* This set's members in canonical array form.
* @serial
*/
private int[][] members;
/**
* Construct a new set-of-integer attribute with the given members in
* string form.
*
* @param members Set members in string form. If null, an empty set is
* constructed.
*
* @exception IllegalArgumentException
* (Unchecked exception) Thrown if members does not
* obey the proper syntax.
*/
protected SetOfIntegerSyntax(String members) {
this.members = parse (members);
}
/**
* Parse the given string, returning canonical array form.
*/
private static int[][] parse(String members) {
// Create vector to hold int[] elements, each element being one range
// parsed out of members.
Vector theRanges = new Vector();
// Run state machine over members.
int n = (members == null ? 0 : members.length());
int i = 0;
int state = 0;
int lb = 0;
int ub = 0;
char c;
int digit;
while (i < n) {
c = members.charAt(i ++);
switch (state) {
case 0: // Before first integer in first group
if (Character.isWhitespace(c)) {
state = 0;
}
else if ((digit = Character.digit(c, 10)) != -1) {
lb = digit;
state = 1;
} else {
throw new IllegalArgumentException();
}
break;
case 1: // In first integer in a group
if (Character.isWhitespace(c)){
state = 2;
} else if ((digit = Character.digit(c, 10)) != -1) {
lb = 10 * lb + digit;
state = 1;
} else if (c == '-' || c == ':') {
state = 3;
} else if (c == ',') {
accumulate (theRanges, lb, lb);
state = 6;
} else {
throw new IllegalArgumentException();
}
break;
case 2: // After first integer in a group
if (Character.isWhitespace(c)) {
state = 2;
}
else if (c == '-' || c == ':') {
state = 3;
}
else if (c == ',') {
accumulate(theRanges, lb, lb);
state = 6;
} else {
throw new IllegalArgumentException();
}
break;
case 3: // Before second integer in a group
if (Character.isWhitespace(c)) {
state = 3;
} else if ((digit = Character.digit(c, 10)) != -1) {
ub = digit;
state = 4;
} else {
throw new IllegalArgumentException();
}
break;
case 4: // In second integer in a group
if (Character.isWhitespace(c)) {
state = 5;
} else if ((digit = Character.digit(c, 10)) != -1) {
ub = 10 * ub + digit;
state = 4;
} else if (c == ',') {
accumulate(theRanges, lb, ub);
state = 6;
} else {
throw new IllegalArgumentException();
}
break;
case 5: // After second integer in a group
if (Character.isWhitespace(c)) {
state = 5;
} else if (c == ',') {
accumulate(theRanges, lb, ub);
state = 6;
} else {
throw new IllegalArgumentException();
}
break;
case 6: // Before first integer in second or later group
if (Character.isWhitespace(c)) {
state = 6;
} else if ((digit = Character.digit(c, 10)) != -1) {
lb = digit;
state = 1;
} else {
throw new IllegalArgumentException();
}
break;
}
}
// Finish off the state machine.
switch (state) {
case 0: // Before first integer in first group
break;
case 1: // In first integer in a group
case 2: // After first integer in a group
accumulate(theRanges, lb, lb);
break;
case 4: // In second integer in a group
case 5: // After second integer in a group
accumulate(theRanges, lb, ub);
break;
case 3: // Before second integer in a group
case 6: // Before first integer in second or later group
throw new IllegalArgumentException();
}
// Return canonical array form.
return canonicalArrayForm (theRanges);
}
/**
* Accumulate the given range (lb .. ub) into the canonical array form
* into the given vector of int[] objects.
*/
private static void accumulate(Vector ranges, int lb,int ub) {
// Make sure range is non-null.
if (lb <= ub) {
// Stick range at the back of the vector.
ranges.add(new int[] {lb, ub});
// Work towards the front of the vector to integrate the new range
// with the existing ranges.
for (int j = ranges.size()-2; j >= 0; -- j) {
// Get lower and upper bounds of the two ranges being compared.
int[] rangea = (int[]) ranges.elementAt (j);
int lba = rangea[0];
int uba = rangea[1];
int[] rangeb = (int[]) ranges.elementAt (j+1);
int lbb = rangeb[0];
int ubb = rangeb[1];
/* If the two ranges overlap or are adjacent, coalesce them.
* The two ranges overlap if the larger lower bound is less
* than or equal to the smaller upper bound. The two ranges
* are adjacent if the larger lower bound is one greater
* than the smaller upper bound.
*/
if (Math.max(lba, lbb) - Math.min(uba, ubb) <= 1) {
// The coalesced range is from the smaller lower bound to
// the larger upper bound.
ranges.setElementAt(new int[]
{Math.min(lba, lbb),
Math.max(uba, ubb)}, j);
ranges.remove (j+1);
} else if (lba > lbb) {
/* If the two ranges don't overlap and aren't adjacent but
* are out of order, swap them.
*/
ranges.setElementAt (rangeb, j);
ranges.setElementAt (rangea, j+1);
} else {
/* If the two ranges don't overlap and aren't adjacent and
* aren't out of order, we're done early.
*/
break;
}
}
}
}
/**
* Convert the given vector of int[] objects to canonical array form.
*/
private static int[][] canonicalArrayForm(Vector ranges) {
return (int[][]) ranges.toArray (new int[ranges.size()][]);
}
/**
* Construct a new set-of-integer attribute with the given members in
* array form.
*
* @param members Set members in array form. If null, an empty set is
* constructed.
*
* @exception NullPointerException
* (Unchecked exception) Thrown if any element of
* members is null.
* @exception IllegalArgumentException
* (Unchecked exception) Thrown if any element of
* members is not a length-one or length-two array or if
* any non-null range in members has a lower bound less
* than zero.
*/
protected SetOfIntegerSyntax(int[][] members) {
this.members = parse (members);
}
/**
* Parse the given array form, returning canonical array form.
*/
private static int[][] parse(int[][] members) {
// Create vector to hold int[] elements, each element being one range
// parsed out of members.
Vector ranges = new Vector();
// Process all integer groups in members.
int n = (members == null ? 0 : members.length);
for (int i = 0; i < n; ++ i) {
// Get lower and upper bounds of the range.
int lb, ub;
if (members[i].length == 1) {
lb = ub = members[i][0];
} else if (members[i].length == 2) {
lb = members[i][0];
ub = members[i][1];
} else {
throw new IllegalArgumentException();
}
// Verify valid bounds.
if (lb <= ub && lb < 0) {
throw new IllegalArgumentException();
}
// Accumulate the range.
accumulate(ranges, lb, ub);
}
// Return canonical array form.
return canonicalArrayForm (ranges);
}
/**
* Construct a new set-of-integer attribute containing a single integer.
*
* @param member Set member.
*
* @exception IllegalArgumentException
* (Unchecked exception) Thrown if member is less than
* zero.
*/
protected SetOfIntegerSyntax(int member) {
if (member < 0) {
throw new IllegalArgumentException();
}
members = new int[][] {{member, member}};
}
/**
* Construct a new set-of-integer attribute containing a single range of
* integers. If the lower bound is greater than the upper bound (a null
* range), an empty set is constructed.
*
* @param lowerBound Lower bound of the range.
* @param upperBound Upper bound of the range.
*
* @exception IllegalArgumentException
* (Unchecked exception) Thrown if the range is non-null and
* lowerBound is less than zero.
*/
protected SetOfIntegerSyntax(int lowerBound, int upperBound) {
if (lowerBound <= upperBound && lowerBound < 0) {
throw new IllegalArgumentException();
}
members = lowerBound <=upperBound ?
new int[][] {{lowerBound, upperBound}} :
new int[0][];
}
/**
* Obtain this set-of-integer attribute's members in canonical array form.
* The returned array is "safe;" the client may alter it without affecting
* this set-of-integer attribute.
*
* @return This set-of-integer attribute's members in canonical array form.
*/
public int[][] getMembers() {
int n = members.length;
int[][] result = new int[n][];
for (int i = 0; i < n; ++ i) {
result[i] = new int[] {members[i][0], members[i][1]};
}
return result;
}
/**
* Determine if this set-of-integer attribute contains the given value.
*
* @param x Integer value.
*
* @return True if this set-of-integer attribute contains the value
* x, false otherwise.
*/
public boolean contains(int x) {
// Do a linear search to find the range that contains x, if any.
int n = members.length;
for (int i = 0; i < n; ++ i) {
if (x < members[i][0]) {
return false;
} else if (x <= members[i][1]) {
return true;
}
}
return false;
}
/**
* Determine if this set-of-integer attribute contains the given integer
* attribute's value.
*
* @param attribute Integer attribute.
*
* @return True if this set-of-integer attribute contains
* theAttribute's value, false otherwise.
*/
public boolean contains(IntegerSyntax attribute) {
return contains (attribute.getValue());
}
/**
* Determine the smallest integer in this set-of-integer attribute that is
* greater than the given value. If there are no integers in this
* set-of-integer attribute greater than the given value, -1 is
* returned. (Since a set-of-integer attribute can only contain nonnegative
* values, -1 will never appear in the set.) You can use the
* next() method to iterate through the integer values in a
* set-of-integer attribute in ascending order, like this:
*
* SetOfIntegerSyntax attribute = . . .;
* int i = -1;
* while ((i = attribute.next (i)) != -1)
* {
* foo (i);
* }
*
*
* @param x Integer value.
*
* @return The smallest integer in this set-of-integer attribute that is
* greater than x, or -1 if no integer in
* this set-of-integer attribute is greater than x.
*/
public int next(int x) {
// Do a linear search to find the range that contains x, if any.
int n = members.length;
for (int i = 0; i < n; ++ i) {
if (x < members[i][0]) {
return members[i][0];
} else if (x < members[i][1]) {
return x + 1;
}
}
return -1;
}
/**
* Returns whether this set-of-integer attribute is equivalent to the passed
* in object. To be equivalent, all of the following conditions must be
* true:
* object is not null.
* object is an instance of class SetOfIntegerSyntax.
* object's
* members are the same.
* object is equivalent to this
* set-of-integer attribute, false otherwise.
*/
public boolean equals(Object object) {
if (object != null && object instanceof SetOfIntegerSyntax) {
int[][] myMembers = this.members;
int[][] otherMembers = ((SetOfIntegerSyntax) object).members;
int m = myMembers.length;
int n = otherMembers.length;
if (m == n) {
for (int i = 0; i < m; ++ i) {
if (myMembers[i][0] != otherMembers[i][0] ||
myMembers[i][1] != otherMembers[i][1]) {
return false;
}
}
return true;
} else {
return false;
}
} else {
return false;
}
}
/**
* Returns a hash code value for this set-of-integer attribute. The hash
* code is the sum of the lower and upper bounds of the ranges in the
* canonical array form, or 0 for an empty set.
*/
public int hashCode() {
int result = 0;
int n = members.length;
for (int i = 0; i < n; ++ i) {
result += members[i][0] + members[i][1];
}
return result;
}
/**
* Returns a string value corresponding to this set-of-integer attribute.
* The string value is a zero-length string if this set is empty. Otherwise,
* the string value is a comma-separated list of the ranges in the canonical
* array form, where each range is represented as "i" if
* the lower bound equals the upper bound or
* "i-j" otherwise.
*/
public String toString() {
StringBuffer result = new StringBuffer();
int n = members.length;
for (int i = 0; i < n; i++) {
if (i > 0) {
result.append (',');
}
result.append (members[i][0]);
if (members[i][0] != members[i][1]) {
result.append ('-');
result.append (members[i][1]);
}
}
return result.toString();
}
}