/// <summary>
/// Gets the index of the first occurrence of any element in the specified array.
/// </summary>
/// <param name="rope">The target rope.</param>
/// <param name="anyOf">Array of characters being searched.</param>
/// <param name="startIndex">Start index of the search.</param>
/// <param name="length">Length of the area to search.</param>
/// <returns>The first index where any character was found; or -1 if no occurrence was found.</returns>
public static int IndexOfAny(this Rope <char> rope, char[] anyOf, int startIndex, int length)
{
if (rope == null)
{
throw new ArgumentNullException(nameof(rope));
}
if (anyOf == null)
{
throw new ArgumentNullException(nameof(anyOf));
}
rope.VerifyRange(startIndex, length);
while (length > 0)
{
var entry = rope.FindNodeUsingCache(startIndex).PeekOrDefault();
char[] contents = entry.Node.Contents;
int startWithinNode = startIndex - entry.NodeStartIndex;
int nodeLength = Math.Min(entry.Node.Length, startWithinNode + length);
for (int i = startIndex - entry.NodeStartIndex; i < nodeLength; i++)
{
char element = contents[i];
foreach (char needle in anyOf)
{
if (element == needle)
{
return(entry.NodeStartIndex + i);
}
}
}
length -= nodeLength - startWithinNode;
startIndex = entry.NodeStartIndex + nodeLength;
}
return(-1);
}