/**
* Returns the length of a matching string starting at the
* specified position. The number of matches to skip can also
* be specified, but numbers higher than zero (0) cause a
* failed match for any element that doesn't attempt to
* combine other elements.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the longest matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
public override int Match(Matcher m,
ReaderBuffer buffer,
int start,
int skip) {
int length = 0;
int length1 = -1;
int length2 = -1;
int skip1 = 0;
int skip2 = 0;
while (length >= 0 && skip1 + skip2 <= skip) {
length1 = elem1.Match(m, buffer, start, skip1);
length2 = elem2.Match(m, buffer, start, skip2);
if (length1 >= length2) {
length = length1;
skip1++;
} else {
length = length2;
skip2++;
}
}
return length;
}
/**
* Returns the length of a matching string starting at the
* specified position. The number of matches to skip can also be
* specified, but numbers higher than zero (0) cause a failed
* match for any element that doesn't attempt to combine other
* elements.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
public override int Match(Matcher m,
ReaderBuffer buffer,
int start,
int skip) {
int c;
if (skip != 0) {
return -1;
}
c = buffer.Peek(start);
if (c < 0) {
m.SetReadEndOfString();
return -1;
}
if (m.IsCaseInsensitive()) {
c = (int) Char.ToLower((char) c);
}
return InSet((char) c) ? 1 : -1;
}
/**
* Returns the length of a matching string starting at the
* specified position. The number of matches to skip can also
* be specified, but numbers higher than zero (0) cause a
* failed match for any element that doesn't attempt to
* combine other elements.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the longest matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
public override int Match(Matcher m,
ReaderBuffer buffer,
int start,
int skip) {
int c;
if (skip != 0) {
return -1;
}
for (int i = 0; i < value.Length; i++) {
c = buffer.Peek(start + i);
if (c < 0) {
m.SetReadEndOfString();
return -1;
}
if (m.IsCaseInsensitive()) {
c = (int) Char.ToLower((char) c);
}
if (c != (int) value[i]) {
return -1;
}
}
return value.Length;
}
/**
* Returns the length of a matching string starting at the
* specified position. The number of matches to skip can also
* be specified, but numbers higher than zero (0) cause a
* failed match for any element that doesn't attempt to
* combine other elements.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
public abstract int Match(Matcher m,
ReaderBuffer buffer,
int start,
int skip);
/**
* Returns the length of the shortest possible matching string
* starting at the specified position. The number of matches to
* skip can also be specified.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the shortest matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
private int MatchReluctant(Matcher m,
ReaderBuffer buffer,
int start,
int skip)
{
// Find all matches
if (matchStart != start) {
matchStart = start;
matches = new BitArray(10);
FindMatches(m, buffer, start, 0, 0, 0);
}
// Find first non-skipped match
for (int i = 0; i < matches.Count; i++) {
if (matches[i]) {
if (skip == 0) {
return i;
}
skip--;
}
}
return -1;
}
/**
* Returns the length of the maximum number of elements matching
* the string starting at the specified position. This method
* allows no backtracking, i.e. no skips..
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param count the start count, normally zero (0)
*
* @return the length of the longest matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
private int MatchPossessive(Matcher m,
ReaderBuffer buffer,
int start,
int count)
{
int length = 0;
int subLength = 1;
// Match as many elements as possible
while (subLength > 0 && count < max) {
subLength = elem.Match(m, buffer, start + length, 0);
if (subLength >= 0) {
count++;
length += subLength;
}
}
// Return result
if (min <= count && count <= max) {
return length;
} else {
return -1;
}
}
/**
* Returns the length of the longest possible matching string
* starting at the specified position. The number of matches
* to skip can also be specified.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the longest matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
private int MatchGreedy(Matcher m,
ReaderBuffer buffer,
int start,
int skip)
{
// Check for simple case
if (skip == 0) {
return MatchPossessive(m, buffer, start, 0);
}
// Find all matches
if (matchStart != start) {
matchStart = start;
matches = new BitArray(10);
FindMatches(m, buffer, start, 0, 0, 0);
}
// Find first non-skipped match
for (int i = matches.Count - 1; i >= 0; i--) {
if (matches[i]) {
if (skip == 0) {
return i;
}
skip--;
}
}
return -1;
}
/**
* Finds all matches and adds the lengths to the matches set.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param length the match length at the start position
* @param count the number of sub-elements matched
* @param attempt the number of match attempts here
*
* @throws IOException if an I/O error occurred
*/
private void FindMatches(Matcher m,
ReaderBuffer buffer,
int start,
int length,
int count,
int attempt)
{
int subLength;
// Check match ending here
if (count > max) {
return;
}
if (min <= count && attempt == 0) {
if (matches.Length <= length) {
matches.Length = length + 10;
}
matches[length] = true;
}
// Check element match
subLength = elem.Match(m, buffer, start, attempt);
if (subLength < 0) {
return;
} else if (subLength == 0) {
if (min == count + 1) {
if (matches.Length <= length) {
matches.Length = length + 10;
}
matches[length] = true;
}
return;
}
// Find alternative and subsequent matches
FindMatches(m, buffer, start, length, count, attempt + 1);
FindMatches(m,
buffer,
start + subLength,
length + subLength,
count + 1,
0);
}
/**
* Returns the length of a matching string starting at the
* specified position. The number of matches to skip can also be
* specified.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
public override int Match(Matcher m,
ReaderBuffer buffer,
int start,
int skip)
{
if (skip == 0) {
matchStart = -1;
matches = null;
}
switch (type) {
case RepeatType.GREEDY:
return MatchGreedy(m, buffer, start, skip);
case RepeatType.RELUCTANT:
return MatchReluctant(m, buffer, start, skip);
case RepeatType.POSSESSIVE:
if (skip == 0) {
return MatchPossessive(m, buffer, start, 0);
}
break;
}
return -1;
}
/**
* Returns the length of a matching string starting at the
* specified position. The number of matches to skip can also be
* specified, but numbers higher than zero (0) cause a failed
* match for any element that doesn't attempt to combine other
* elements.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the longest matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
public override int Match(Matcher m,
ReaderBuffer buffer,
int start,
int skip) {
int length1 = -1;
int length2 = 0;
int skip1 = 0;
int skip2 = 0;
while (skip >= 0) {
length1 = elem1.Match(m, buffer, start, skip1);
if (length1 < 0) {
return -1;
}
length2 = elem2.Match(m, buffer, start + length1, skip2);
if (length2 < 0) {
skip1++;
skip2 = 0;
} else {
skip2++;
skip--;
}
}
return length1 + length2;
}
/**
* Checks if the start of the input stream matches this
* regular expression.
*
* @param buffer the input buffer to check
*
* @return the longest match found, or
* zero (0) if no match was found
*
* @throws IOException if an I/O error occurred
*/
public override int Match(ReaderBuffer buffer) {
if (matcher == null) {
matcher = regExp.Matcher(buffer);
} else {
matcher.Reset(buffer);
}
return matcher.MatchFromBeginning() ? matcher.Length() : 0;
}
/// <summary>
/// Finds all matches and adds the lengths to the matches set.
/// </summary>
/// <param name="m">the matcher being used</param>
/// <param name="buffer">The input character buffer to match</param>
/// <param name="start">The starting position</param>
/// <param name="length">The match length at the start position</param>
/// <param name="count">The number of sub-elements matched</param>
/// <param name="attempt">The number of match attempts here</param>
/// <exception cref="IOException">If an I/O error occurred</exception>
private void FindMatches(
Matcher m,
ReaderBuffer buffer,
int start,
int length,
int count,
int attempt)
{
int subLength;
// Check match ending here
if (count > this.max)
{
return;
}
if (this.min <= count && attempt == 0)
{
if (this.matches.Length <= length)
{
this.matches.Length = length + 10;
}
this.matches[length] = true;
}
// Check element match
subLength = this.elem.Match(m, buffer, start, attempt);
if (subLength < 0)
{
return;
}
else if (subLength == 0)
{
if (this.min == count + 1)
{
if (this.matches.Length <= length)
{
this.matches.Length = length + 10;
}
this.matches[length] = true;
}
return;
}
// Find alternative and subsequent matches
this.FindMatches(
m,
buffer,
start,
length,
count,
attempt + 1);
this.FindMatches(
m,
buffer,
start + subLength,
length + subLength,
count + 1,
0);
}
/**
* Returns the length of a matching string starting at the
* specified position. The number of matches to skip can also
* be specified, but numbers higher than zero (0) cause a
* failed match for any element that doesn't attempt to
* combine other elements.
*
* @param m the matcher being used
* @param buffer the input character buffer to match
* @param start the starting position
* @param skip the number of matches to skip
*
* @return the length of the matching string, or
* -1 if no match was found
*
* @throws IOException if an I/O error occurred
*/
public abstract int Match(Matcher m,
ReaderBuffer buffer,
int start,
int skip);
