/// <summary>
/// Advances the enumerator to the next element of the collection.
/// </summary>
/// <returns>
/// <see langword="true"/> if the enumerator was successfully advanced to the next element;
/// <see langword="false"/> if the enumerator has passed the end of the collection.
/// </returns>
public bool MoveNext()
{
// Get the first char if we're at the beginning of the string.
if (this.first)
{
LineBreakClass firstClass = this.NextCharClass();
this.first = false;
this.currentClass = this.MapFirst(firstClass);
this.nextClass = firstClass;
this.lb8a = firstClass == LineBreakClass.ZWJ;
this.lb30a = 0;
}
while (this.position < this.pointsLength)
{
this.lastPosition = this.position;
LineBreakClass lastClass = this.nextClass;
this.nextClass = this.NextCharClass();
// Explicit newline
switch (this.currentClass)
{
case LineBreakClass.BK:
case LineBreakClass.CR when this.nextClass != LineBreakClass.LF:
this.currentClass = this.MapFirst(this.nextClass);
this.Current = new LineBreak(this.FindPriorNonWhitespace(this.lastPosition), this.lastPosition, true);
return(true);
}
bool?shouldBreak = this.GetSimpleBreak() ?? (bool?)this.GetPairTableBreak(lastClass);
// Rule LB8a
this.lb8a = this.nextClass == LineBreakClass.ZWJ;
if (shouldBreak.Value)
{
this.Current = new LineBreak(this.FindPriorNonWhitespace(this.lastPosition), this.lastPosition, false);
return(true);
}
}
if (this.position >= this.pointsLength && this.lastPosition < this.pointsLength)
{
this.lastPosition = this.pointsLength;
bool required = false;
switch (this.currentClass)
{
case LineBreakClass.BK:
case LineBreakClass.CR when this.nextClass != LineBreakClass.LF:
required = true;
break;
}
this.Current = new LineBreak(this.FindPriorNonWhitespace(this.pointsLength), this.lastPosition, required);
return(true);
}
this.Current = default;
return(false);
}
/// <summary>
/// Returns the line break from the current code points if one is found.
/// </summary>
/// <param name="lineBreak">
/// When this method returns, contains the value associate with the break;
/// otherwise, the default value.
/// This parameter is passed uninitialized.</param>
/// <returns>The <see cref="bool"/>.</returns>
public bool TryGetNextBreak(out LineBreak lineBreak)
{
// get the first char if we're at the beginning of the string
if (this.first)
{
this.first = false;
LineBreakClass firstClass = this.NextCharClass();
this.currentClass = this.MapFirst(firstClass);
this.nextClass = firstClass;
this.lb8a = firstClass == LineBreakClass.ZWJ;
this.lb30a = 0;
}
while (this.position < this.codePoints.Length)
{
this.lastPosition = this.position;
LineBreakClass lastClass = this.nextClass;
this.nextClass = this.NextCharClass();
// explicit newline
if ((this.currentClass == LineBreakClass.BK) || ((this.currentClass == LineBreakClass.CR) && (this.nextClass != LineBreakClass.LF)))
{
this.currentClass = this.MapFirst(this.MapClass(this.nextClass));
lineBreak = new LineBreak(this.FindPriorNonWhitespace(this.lastPosition), this.lastPosition, true);
return(true);
}
bool?shouldBreak = this.GetSimpleBreak();
if (!shouldBreak.HasValue)
{
shouldBreak = this.GetPairTableBreak(lastClass);
}
// Rule LB8a
this.lb8a = this.nextClass == LineBreakClass.ZWJ;
if (shouldBreak.Value)
{
lineBreak = new LineBreak(this.FindPriorNonWhitespace(this.lastPosition), this.lastPosition, false);
return(true);
}
}
if (this.lastPosition < this.codePoints.Length)
{
this.lastPosition = this.codePoints.Length;
bool required = (this.currentClass == LineBreakClass.BK) || ((this.currentClass == LineBreakClass.CR) && (this.nextClass != LineBreakClass.LF));
lineBreak = new LineBreak(this.FindPriorNonWhitespace(this.codePoints.Length), this.lastPosition, required);
return(true);
}
else
{
lineBreak = default;
return(false);
}
}