/// <summary>
/// Finds the next (string, value) pair if there is one.
/// </summary>
/// <remarks>
/// If the string is truncated to the maximum length and does not
/// have a real value, then the value is set to -1.
/// In this case, this "not a real value" is indistinguishable from
/// a real value of -1.
/// </remarks>
/// <returns>An <see cref="CharsTrieEntry"/> with the string and value of the next element.</returns>
/// <stable>ICU 4.8</stable>
private CharsTrieEntry Next()
{
int pos = pos_;
if (pos < 0)
{
//if (stack_.isEmpty())
//{
// throw new NoSuchElementException();
//}
// Pop the state off the stack and continue with the next outbound edge of
// the branch node.
long top = stack_[stack_.Count - 1];
stack_.Remove(top);
int length = (int)top;
pos = (int)(top >> 32);
str_.Length = (length & 0xffff);
length = length.TripleShift(16);
if (length > 1)
{
pos = BranchNext(pos, length);
if (pos < 0)
{
return(entry_); // Reached a final value.
}
}
else
{
str_.Append(chars_[pos++]);
}
}
if (remainingMatchLength_ >= 0)
{
// We only get here if we started in a pending linear-match node
// with more than maxLength remaining units.
return(TruncateAndStop());
}
for (; ;)
{
int node = chars_[pos++];
if (node >= CharsTrie.kMinValueLead)
{
if (skipValue_)
{
pos = CharsTrie.SkipNodeValue(pos, node);
node &= CharsTrie.kNodeTypeMask;
skipValue_ = false;
}
else
{
// Deliver value for the string so far.
bool isFinal = (node & CharsTrie.kValueIsFinal) != 0;
if (isFinal)
{
entry_.Value = CharsTrie.ReadValue(chars_, pos, node & 0x7fff);
}
else
{
entry_.Value = CharsTrie.ReadNodeValue(chars_, pos, node);
}
if (isFinal || (maxLength_ > 0 && str_.Length == maxLength_))
{
pos_ = -1;
}
else
{
// We cannot skip the value right here because it shares its
// lead unit with a match node which we have to evaluate
// next time.
// Instead, keep pos_ on the node lead unit itself.
pos_ = pos - 1;
skipValue_ = true;
}
entry_.Chars = str_.AsCharSequence();
return(entry_);
}
}
if (maxLength_ > 0 && str_.Length == maxLength_)
{
return(TruncateAndStop());
}
if (node < CharsTrie.kMinLinearMatch)
{
if (node == 0)
{
node = chars_[pos++];
}
pos = BranchNext(pos, node + 1);
if (pos < 0)
{
return(entry_); // Reached a final value.
}
}
else
{
// Linear-match node, append length units to str_.
int length = node - CharsTrie.kMinLinearMatch + 1;
if (maxLength_ > 0 && str_.Length + length > maxLength_)
{
str_.Append(chars_, pos, maxLength_ - str_.Length); // ICU4N: (pos + maxLength_ - str_.Length) - pos == (maxLength_ - str_.Length)
return(TruncateAndStop());
}
str_.Append(chars_, pos, length); // ICU4N: (pos + length) - pos == length
pos += length;
}
}
}