/// <summary>
/// Removes all the leading occurrences of a set of runes specified in an array from the current string.
/// </summary>
/// <param name="source">The current string.</param>
/// <param name="trimRunes">An array of <see cref="Rune"/> to remove, or <see langword="null"/>.</param>
/// <returns>
/// The string that remains after all occurrences of the runes in the <paramref name="trimRunes"/> parameter are removed from the start of the current string. If <paramref name="trimRunes"/> is <see langword="null"/> or an empty array, Unicode white-space runes are removed instead. If no runes can be trimmed from the current instance, the method returns the current instance unchanged.
/// </returns>
public static String TrimStart(this String source, params Rune[] trimRunes)
{
if (trimRunes is null || trimRunes.Length == 0)
{
// There's no point in replicating whitespace removal behavior, so just call the existing one to do that work.
return(source.TrimEnd());
}
Rune[] runes = source.EnumerateRunes().ToArray();
Int32 r = 0;
Int32 l = runes.Length - 1;
foreach (Rune trim in trimRunes)
{
if (runes[r++] == trim)
{
l--;
}
else
{
break;
}
}
Rune[] result = new Rune[l];
Array.Copy(runes, ++r, result, 0, l);
return(result.AsString());
}
public void AsString_Runes(Int32[] scalarValues, String expected)
{
Rune[] runes = new Rune[scalarValues.Length];
for (Int32 i = 0; i < runes.Length; i++)
{
runes[i] = new Rune(scalarValues[i]);
}
Assert.Equal(expected, runes.AsString());
}
/// <summary>
/// Repeat the <paramref name="rune"/> <paramref name="count"/> times.
/// </summary>
/// <param name="rune">The <see cref="Rune"/> to repeat.</param>
/// <param name="count">The amount of times to repeat the <paramref name="rune"/>.</param>
/// <returns>A <see cref="String"/> containing the repeated <paramref name="rune"/>.</returns>
public static String Repeat(this Rune rune, Int32 count)
{
Guard.GreaterThanOrEqualTo(count, nameof(count), 0);
Rune[] runes = new Rune[count];
for (int i = 0; i < count; i++)
{
runes[i] = rune;
}
return(runes.AsString());
}
