/// <summary>
/// Find the source and target sets, subject to the input filter.
/// There is a known issue with filters containing multiple characters.
/// </summary>
// TODO: Problem: the rule is [{ab}]c > x
// The filter is [a{bc}].
// If the input is abc, then the rule will work.
// However, following code applying the filter won't catch that case.
internal void AddSourceTargetSet(UnicodeSet filter, UnicodeSet sourceSet, UnicodeSet targetSet, UnicodeSet revisiting)
{
int limit = anteContextLength + keyLength;
UnicodeSet tempSource = new UnicodeSet();
UnicodeSet temp = new UnicodeSet();
// We need to walk through the pattern.
// Iff some of the characters at ALL of the the positions are matched by the filter, then we add temp to toUnionTo
for (int i = anteContextLength; i < limit;)
{
int ch = UTF16.CharAt(pattern, i);
i += UTF16.GetCharCount(ch);
IUnicodeMatcher matcher = data.LookupMatcher(ch);
if (matcher == null)
{
if (!filter.Contains(ch))
{
return;
}
tempSource.Add(ch);
}
else
{
try
{
if (!filter.ContainsSome((UnicodeSet)matcher))
{
return;
}
matcher.AddMatchSetTo(tempSource);
}
catch (InvalidCastException)
{ // if the matcher is not a UnicodeSet
temp.Clear();
matcher.AddMatchSetTo(temp);
if (!filter.ContainsSome(temp))
{
return;
}
tempSource.AddAll(temp);
}
}
}
// if we made our way through the gauntlet, add to source/target
sourceSet.AddAll(tempSource);
output.AddReplacementSetTo(targetSet);
}
/// <summary>
/// Implementation of <see cref="IUnicodeMatcher"/> API. Union the set of all
/// characters that may be matched by this object into the given
/// set.
/// </summary>
/// <param name="toUnionTo">The set into which to union the source characters.</param>
public virtual void AddMatchSetTo(UnicodeSet toUnionTo)
{
int ch;
for (int i = 0; i < pattern.Length; i += UTF16.GetCharCount(ch))
{
ch = UTF16.CharAt(pattern, i);
IUnicodeMatcher matcher = data.LookupMatcher(ch);
if (matcher == null)
{
toUnionTo.Add(ch);
}
else
{
matcher.AddMatchSetTo(toUnionTo);
}
}
}