private IEnumerable <CharRange> ClipRange(CharRange range, IList <CharRange> excludedCharRanges)
{
char from = range.From;
char to = range.To;
foreach (var excludedRange in excludedCharRanges)
{
// If the range is fully excluded by the excluded range, yield nothing
if (excludedRange.From <= from && excludedRange.To >= to)
{
yield break;
}
// Check if the excluded range is wholly contained within the range
if (excludedRange.From > from && excludedRange.To < to)
{
// Split this range and return
foreach (var charRange in ClipRange(new CharRange {
From = @from, To = (char)(excludedRange.From - 1)
}, excludedCharRanges))
{
yield return(charRange);
}
// Second split
foreach (var charRange in ClipRange(new CharRange {
From = (char)(excludedRange.To + 1), To = to
}, excludedCharRanges))
{
yield return(charRange);
}
yield break;
}
// Trim the edges of the range
if (to >= excludedRange.From && to <= excludedRange.To)
{
to = (char)(excludedRange.From - 1);
}
if (from >= excludedRange.From && from <= excludedRange.To)
{
from = (char)(excludedRange.To + 1);
}
}
// If the range has been clipped away to nothing, then quit
if (to < from)
{
yield break;
}
// Return the possibly clipped range
yield return(new CharRange {
From = from, To = to
});
}
private IEnumerable <CharRange> FindNewRanges(CharRange range, List <CharRange> distinguishedRanges)
{
int a = 0;
int b = distinguishedRanges.Count;
int startIndex = 0;
while (true)
{
int pivot = a + (b - a) / 2;
int cmp = range.From - distinguishedRanges[pivot].From;
if (cmp == 0)
{
startIndex = pivot;
break;
}
if (cmp < 0)
{
b = pivot;
}
else
{
a = pivot;
}
}
int a2 = startIndex;
int b2 = distinguishedRanges.Count;
char c = range.To == char.MaxValue ? range.To : (char)(range.To + 1);
while (true)
{
int pivot = a2 + (b2 - a2) / 2;
int cmp = c - distinguishedRanges[pivot].To;
if (cmp == 0)
{
for (int i = startIndex; i <= pivot; ++i)
{
CharRange f = distinguishedRanges[i];
yield return(new CharRange {
From = f.From, To = f.To == char.MaxValue ? f.To : (char)(f.To - 1)
});
}
yield break;
}
if (cmp < 0)
{
b2 = pivot;
}
else
{
a2 = pivot;
}
}
}
public bool DistinguishRanges(CharSet other)
{
bool changes = false;
ISet<CharRange> newRanges = new HashSet<CharRange>();
// For each of the ranges that this set contains, if there is another range that intersects
// create new ranges so that there is no intersecting ranges
for (int i = 0; i < ranges.Count; ++i )
{
var r = ranges[i];
foreach (var r2 in other.ranges)
{
// If from is inside the range (not on borders), split the range
if (r2.From > r.From && r2.From <= r.To)
{
var oldTo = r.To;
r.To = (char) (r2.From - 1);
var newRange = new CharRange { From = r2.From, To = oldTo };
newRanges.Add(newRange);
changes = true;
}
// Same thing goes for to
if (r2.To >= r.From && r2.To < r.To)
{
var oldTo = r.To;
r.To = r2.To;
var newRange = new CharRange { From = (char) (r2.To + 1), To = oldTo };
newRanges.Add(newRange);
changes = true;
}
}
newRanges.Add(r);
}
ranges = newRanges.ToList();
return changes;
}
private IEnumerable<CharRange> ClipRange(CharRange range, IList<CharRange> excludedCharRanges)
{
char from = range.From;
char to = range.To;
foreach (var excludedRange in excludedCharRanges)
{
// If the range is fully excluded by the excluded range, yield nothing
if (excludedRange.From <= from && excludedRange.To >= to)
{
yield break;
}
// Check if the excluded range is wholly contained within the range
if (excludedRange.From > from && excludedRange.To < to )
{
// Split this range and return
foreach (var charRange in ClipRange(new CharRange {From = @from, To = (char)(excludedRange.From - 1)}, excludedCharRanges))
{
yield return charRange;
}
// Second split
foreach (var charRange in ClipRange(new CharRange { From = (char)(excludedRange.To + 1), To = to }, excludedCharRanges))
{
yield return charRange;
}
yield break;
}
// Trim the edges of the range
if (to >= excludedRange.From && to <= excludedRange.To)
{
to = (char)(excludedRange.From - 1);
}
if (from >= excludedRange.From && from <= excludedRange.To)
{
from = (char)(excludedRange.To + 1);
}
}
// If the range has been clipped away to nothing, then quit
if (to < from)
yield break;
// Return the possibly clipped range
yield return new CharRange { From = from, To = to};
}