// private methods ------------------------------------------------
/// <summary>
/// Set the result values.
/// </summary>
/// <param name="element">Return result object.</param>
/// <param name="start">Start codepoint of range.</param>
/// <param name="limit">(end + 1) codepoint of range.</param>
/// <param name="value">Common value of range.</param>
private void SetResult(Element element, int start, int limit,
int value)
{
element.Start = start;
element.Limit = limit;
element.Value = value;
}
/// <summary>
/// Returns true if we are not at the end of the iteration, false
/// otherwise.
/// The next set of codepoints with the same value type will be
/// calculated during this call and set to <see cref="Current"/>.
/// </summary>
/// <returns>true if we are not at the end of the iteration, false otherwise.</returns>
/// <seealso cref="Element"/>
public bool MoveNext()
{
var temp = new Element();
var hasNext = Next(temp);
if (hasNext)
{
current = temp;
}
return(hasNext);
}
// public methods -------------------------------------------------
/// <summary>
/// Returns true if we are not at the end of the iteration, false
/// otherwise.
/// The next set of codepoints with the same value type will be
/// calculated during this call and returned in the arguement element.
/// </summary>
/// <param name="element">Return result.</param>
/// <returns>true if we are not at the end of the iteration, false otherwise.</returns>
/// <seealso cref="Element"/>
private bool Next(Element element)
{
if (m_nextCodepoint_ > UCharacter.MAX_VALUE)
{
return(false);
}
if (m_nextCodepoint_ < UCharacter.SUPPLEMENTARY_MIN_VALUE &&
CalculateNextBMPElement(element))
{
return(true);
}
CalculateNextSupplementaryElement(element);
return(true);
}
// public methods -------------------------------------------------
/// <summary>
/// Returns true if we are not at the end of the iteration, false
/// otherwise.
/// The next set of codepoints with the same value type will be
/// calculated during this call and returned in the arguement element.
/// </summary>
/// <param name="element">Return result.</param>
/// <returns>true if we are not at the end of the iteration, false otherwise.</returns>
/// <seealso cref="Element"/>
private bool Next(Element element)
{
if (m_nextCodepoint_ > UChar.MaxValue)
{
return(false);
}
if (m_nextCodepoint_ < UChar.SupplementaryMinValue &&
CalculateNextBMPElement(element))
{
return(true);
}
CalculateNextSupplementaryElement(element);
return(true);
}
/// <summary>
/// Finding the next element.
/// This method is called just before returning the result of
/// <see cref="Next(Element)"/>.
/// We always store the next element before it is requested.
/// In the case that we have to continue calculations into the
/// supplementary planes, a false will be returned.
/// </summary>
/// <param name="element">Return result object.</param>
/// <returns>true if the next range is found, false if we have to proceed to
/// the supplementary range.</returns>
private bool CalculateNextBMPElement(Element element)
{
int currentValue = m_nextValue_;
m_currentCodepoint_ = m_nextCodepoint_;
m_nextCodepoint_++;
m_nextBlockIndex_++;
if (!CheckBlockDetail(currentValue))
{
SetResult(element, m_currentCodepoint_, m_nextCodepoint_,
currentValue);
return(true);
}
// synwee check that next block index == 0 here
// enumerate BMP - the main loop enumerates data blocks
while (m_nextCodepoint_ < UCharacter.SUPPLEMENTARY_MIN_VALUE)
{
// because of the way the character is split to form the index
// the lead surrogate and trail surrogate can not be in the
// mid of a block
if (m_nextCodepoint_ == LEAD_SURROGATE_MIN_VALUE_)
{
// skip lead surrogate code units,
// go to lead surrogate codepoints
m_nextIndex_ = BMP_INDEX_LENGTH_;
}
else if (m_nextCodepoint_ == TRAIL_SURROGATE_MIN_VALUE_)
{
// go back to regular BMP code points
m_nextIndex_ = m_nextCodepoint_ >> Trie.INDEX_STAGE_1_SHIFT_;
}
else
{
m_nextIndex_++;
}
m_nextBlockIndex_ = 0;
if (!CheckBlock(currentValue))
{
SetResult(element, m_currentCodepoint_, m_nextCodepoint_,
currentValue);
return(true);
}
}
m_nextCodepoint_--; // step one back since this value has not been
m_nextBlockIndex_--; // retrieved yet.
return(false);
}
/// <summary>
/// Finds the next supplementary element.
/// For each entry in the trie, the value to be delivered is passed through
/// <see cref="Extract(int)"/>.
/// We always store the next element before it is requested.
/// Called after <see cref="CalculateNextBMPElement(Element)"/> completes its round of BMP characters.
/// There is a slight difference in the usage of <see cref="m_currentCodepoint_"/>.
/// here as compared to <see cref="CalculateNextBMPElement(Element)"/>. Though both represents the
/// lower bound of the next element, in <see cref="CalculateNextBMPElement(Element)"/> it gets set
/// at the start of any loop, where-else, in <see cref="CalculateNextSupplementaryElement(Element)"/>
/// since <see cref="m_currentCodepoint_"/> already contains the lower bound of the
/// next element (passed down from <see cref="CalculateNextBMPElement(Element)"/>), we keep it till
/// the end before resetting it to the new value.
/// Note, if there are no more iterations, it will never get to here.
/// Blocked out by <see cref="Next(Element)"/>.
/// </summary>
/// <param name="element">Return result object.</param>
private void CalculateNextSupplementaryElement(Element element)
{
int currentValue = m_nextValue_;
m_nextCodepoint_++;
m_nextBlockIndex_++;
if (UTF16.GetTrailSurrogate(m_nextCodepoint_)
!= UTF16.TRAIL_SURROGATE_MIN_VALUE)
{
// this piece is only called when we are in the middle of a lead
// surrogate block
if (!CheckNullNextTrailIndex() && !CheckBlockDetail(currentValue))
{
SetResult(element, m_currentCodepoint_, m_nextCodepoint_,
currentValue);
m_currentCodepoint_ = m_nextCodepoint_;
return;
}
// we have cleared one block
m_nextIndex_++;
m_nextTrailIndexOffset_++;
if (!CheckTrailBlock(currentValue))
{
SetResult(element, m_currentCodepoint_, m_nextCodepoint_,
currentValue);
m_currentCodepoint_ = m_nextCodepoint_;
return;
}
}
int nextLead = UTF16.GetLeadSurrogate(m_nextCodepoint_);
// enumerate supplementary code points
while (nextLead < TRAIL_SURROGATE_MIN_VALUE_)
{
// lead surrogate access
int leadBlock =
m_trie_.m_index_[nextLead >> Trie.INDEX_STAGE_1_SHIFT_] <<
Trie.INDEX_STAGE_2_SHIFT_;
if (leadBlock == m_trie_.m_dataOffset_)
{
// no entries for a whole block of lead surrogates
if (currentValue != m_initialValue_)
{
m_nextValue_ = m_initialValue_;
m_nextBlock_ = leadBlock; // == m_trie_.m_dataOffset_
m_nextBlockIndex_ = 0;
SetResult(element, m_currentCodepoint_, m_nextCodepoint_,
currentValue);
m_currentCodepoint_ = m_nextCodepoint_;
return;
}
nextLead += DATA_BLOCK_LENGTH_;
// number of total affected supplementary codepoints in one
// block
// this is not a simple addition of
// DATA_BLOCK_SUPPLEMENTARY_LENGTH since we need to consider
// that we might have moved some of the codepoints
m_nextCodepoint_ = Character.ToCodePoint((char)nextLead, (char)UTF16.TRAIL_SURROGATE_MIN_VALUE);
continue;
}
if (m_trie_.m_dataManipulate_ == null)
{
throw new InvalidOperationException(
"The field DataManipulate in this Trie is null"); // ICU4N: This was originally NullPointerException
}
// enumerate trail surrogates for this lead surrogate
m_nextIndex_ = m_trie_.m_dataManipulate_.GetFoldingOffset(
m_trie_[leadBlock +
(nextLead & Trie.INDEX_STAGE_3_MASK_)]);
if (m_nextIndex_ <= 0)
{
// no data for this lead surrogate
if (currentValue != m_initialValue_)
{
m_nextValue_ = m_initialValue_;
m_nextBlock_ = m_trie_.m_dataOffset_;
m_nextBlockIndex_ = 0;
SetResult(element, m_currentCodepoint_, m_nextCodepoint_,
currentValue);
m_currentCodepoint_ = m_nextCodepoint_;
return;
}
m_nextCodepoint_ += TRAIL_SURROGATE_COUNT_;
}
else
{
m_nextTrailIndexOffset_ = 0;
if (!CheckTrailBlock(currentValue))
{
SetResult(element, m_currentCodepoint_, m_nextCodepoint_,
currentValue);
m_currentCodepoint_ = m_nextCodepoint_;
return;
}
}
nextLead++;
}
// deliver last range
SetResult(element, m_currentCodepoint_, UCharacter.MAX_VALUE + 1,
currentValue);
}