/// ------------------------------------------------------------------------------------
/// <summary>
/// Answers the question "Are there any matches?" so that if there aren't,
/// time is not wasted looking for them. To get all the matches, call GetAllResults() next.
/// </summary>
/// <param name="arg">The string to apply the pattern match to.</param>
/// <returns>true if a match was found</returns>
/// ------------------------------------------------------------------------------------
public override bool Matches(ITsString arg)
{
m_currentMatchRangePair.Reset();
try
{
m_currentMatchRangePair = FindFirstMatch(arg);
}
catch (Exception e)
{
System.Diagnostics.Debug.WriteLine(e.Message);
}
// see VwPattern.cpp STDMETHODIMP VwPattern::FindIn documentation for *.IchMin >= 0
return m_currentMatchRangePair.IchMin >= 0;
}
protected MatchRangePair FindNextMatch()
{
int ichStart = 0;
// if we already have a current match, then reset the starting position
// NOTE: there seems to be a bug(?) in FindIn that prevents us from using IchMin + 1 to find overlapping matches.
if (m_currentMatchRangePair.IchMin >= 0)
ichStart = m_currentMatchRangePair.IchLim;
int ichMin;
int ichLim;
m_pattern.FindIn(m_ts, ichStart, m_tssSource.Length, true, out ichMin, out ichLim, null);
m_currentMatchRangePair = new MatchRangePair(ichMin, ichLim);
if (CurrentResultDoesMatch())
{
// Don't duplicate items in the result list. See LT-7041.
int idxLim = m_results.Count - 1;
if (idxLim < 0 || m_results[idxLim].IchMin != m_currentMatchRangePair.IchMin ||
m_results[idxLim].IchLim != m_currentMatchRangePair.IchMin)
{
m_results.Add(m_currentMatchRangePair);
}
}
return m_currentMatchRangePair;
}
/// <summary> /// Override this method to match additional conditions not handled at the pattern level. /// </summary> /// <param name="match">The pattern-matched string segment limits to check against /// additional matching criteria.</param> /// <returns>true if the additional checks succeeded.</returns> abstract protected bool CurrentResultDoesMatch(MatchRangePair match);
/// <summary>
/// Finds the next match satisfying the pattern.
/// For some odd cases like looking for "$" in a regular expression,
/// this will return the same range. The calling code must check.
/// </summary>
/// <param name="lastMatch">A match that has been reset to start or the last one found.</param>
/// <returns>Min and Lim of the segment in the string matching the pattern.</returns>
protected MatchRangePair FindNextPatternMatch(MatchRangePair lastMatch)
{
int ichStart = 0;
// if we already have a current match, then reset the starting position
// NOTE: there seems to be a bug(?) in FindIn that prevents us from using IchMin + 1 to find overlapping matches.
if (lastMatch.IchMin >= 0) // see VwPattern.cpp STDMETHODIMP VwPattern::FindIn documentation
ichStart = lastMatch.IchLim;
int ichMin;
int ichLim;
m_pattern.FindIn(m_ts, ichStart, m_tssSource.Length, true, out ichMin, out ichLim, null);
return new MatchRangePair(ichMin, ichLim);
}
/// <summary>
/// Finds the first match satisfying the abstract method CurrentResultDoesMatch().
/// </summary>
/// <param name="tssSource"></param>
/// <returns>Min and Lim of the segment in the string matching the pattern
/// and CurrentResultDoesMatch or {return}.IchMin = -1 if nothing was found.</returns>
protected MatchRangePair FindFirstMatch(ITsString tssSource)
{
var mrp = new MatchRangePair();
mrp.Reset();
var mrpLast = new MatchRangePair();
mrpLast.Reset();
m_textSourceInit.SetString(tssSource);
m_tssSource = tssSource;
bool found = false;
do
{ // get first/next match and make sure it is not the same segment of the string
mrp = FindNextPatternMatch(mrpLast);
if (mrpLast.Equals(mrp))
break; // it found the same segment again: Prevent cycles, eg, for Reg Exp "$" (LT-7041).
mrpLast = mrp;
found = mrp.IchMin >= 0; // see VwPattern.cpp STDMETHODIMP VwPattern::FindIn documentation
} while (found && !CurrentResultDoesMatch(mrp)); // must match the overridden condition
return mrp;
}
protected override bool CurrentResultDoesMatch(MatchRangePair match)
{
return match.IchMin >= 0;
}
protected override bool CurrentResultDoesMatch(MatchRangePair match)
{
return match.IchLim == m_tssSource.Length;
}
