/// <summary>
/// Returns the number of Unicode code points in the specified text
/// range of this <see cref="StringBuilder"/>. The text range begins at the specified
/// <paramref name="beginIndex"/> and extends to the <see cref="char"/> at
/// index <c>endIndex - 1</c>. Thus the length (in
/// <see cref="char"/>s) of the text range is
/// <c>endIndex-beginIndex</c>. Unpaired surrogates within
/// this sequence count as one code point each.
/// </summary>
/// <param name="text">this <see cref="StringBuilder"/></param>
/// <param name="beginIndex">the index to the first <see cref="char"/> of the text range.</param>
/// <param name="endIndex">the index after the last <see cref="char"/> of the text range.</param>
/// <returns>the number of Unicode code points in the specified text range.</returns>
/// <exception cref="IndexOutOfRangeException">
/// if the <paramref name="beginIndex"/> is negative, or <paramref name="endIndex"/>
/// is larger than the length of this sequence, or
/// <paramref name="beginIndex"/> is larger than <paramref name="endIndex"/>.
/// </exception>
public static int CodePointCount(this StringBuilder text, int beginIndex, int endIndex)
{
if (beginIndex < 0 || endIndex > text.Length || beginIndex > endIndex)
{
throw new IndexOutOfRangeException();
}
return(Character.CodePointCountImpl(text.GetChars(), beginIndex, endIndex - beginIndex));
}
/// <summary>
/// Returns the number of Unicode code points in the specified text
/// range of this <see cref="string"/>. The text range begins at the
/// specified <paramref name="beginIndex"/> and extends to the
/// <see cref="char"/> at index <c>endIndex - 1</c>. Thus the
/// length (in <see cref="char"/>s) of the text range is
/// <c>endIndex-beginIndex</c>. Unpaired surrogates within
/// the text range count as one code point each.
/// </summary>
/// <param name="str"></param>
/// <param name="beginIndex">the index to the first <see cref="char"/> of the text range.</param>
/// <param name="endIndex">the index after the last <see cref="char"/> of the text range.</param>
/// <returns>the number of Unicode code points in the specified text range</returns>
/// <exception cref="IndexOutOfRangeException">if the <paramref name="beginIndex"/> is negative, or
/// <paramref name="endIndex"/> is larger than the length of this <see cref="string"/>, or
/// <paramref name="beginIndex"/> is larger than <paramref name="endIndex"/>.</exception>
public static int CodePointCount(this string str, int beginIndex, int endIndex)
{
if (beginIndex < 0 || endIndex > str.Length || beginIndex > endIndex)
{
throw new IndexOutOfRangeException();
}
return(Character.CodePointCountImpl(str.ToCharArray(), beginIndex, endIndex - beginIndex));
}