/// ------------------------------------------------------------------------------------
/// <summary>
/// Return the full 32-bit character starting at position ich in st
/// </summary>
/// <param name="st">The string.</param>
/// <param name="ich">The character position.</param>
/// <returns></returns>
/// ------------------------------------------------------------------------------------
public static int FullCharAt(string st, int ich)
{
if (Surrogates.IsLeadSurrogate(st[ich]))
{
return(Surrogates.Int32FromSurrogates(st[ich], st[ich + 1]));
}
return(Convert.ToInt32(st[ich]));
}
public void TestSurrogates()
{
Assert.AreEqual(1, Surrogates.NextChar("ab\xD800\xDC00c", 0));
Assert.AreEqual(2, Surrogates.NextChar("ab\xD800\xDC00c", 1));
Assert.AreEqual(4, Surrogates.NextChar("ab\xD800\xDC00c", 2));
Assert.AreEqual(5, Surrogates.NextChar("ab\xD800\xDC00c", 4));
Assert.AreEqual(4, Surrogates.NextChar("ab\xD800\xDC00", 2));
Assert.AreEqual(3, Surrogates.NextChar("ab\xD800", 2), "Badly formed pair at end...don't go too far");
Assert.AreEqual(3, Surrogates.NextChar("ab\xD800c", 2), "Badly formed pair in middle...don't go too far");
Assert.AreEqual(0, Surrogates.PrevChar("ab\xD800\xDC00c", 1));
Assert.AreEqual(1, Surrogates.PrevChar("ab\xD800\xDC00c", 2));
Assert.AreEqual(2, Surrogates.PrevChar("ab\xD800\xDC00c", 3), "initial ich at a bad position, move back normally to sync");
Assert.AreEqual(2, Surrogates.PrevChar("ab\xD800\xDC00c", 4), "double move succeeds");
Assert.AreEqual(4, Surrogates.PrevChar("ab\xD800\xDC00c", 5));
Assert.AreEqual(3, Surrogates.PrevChar("ab\xD800c", 4), "no double move on bad pair");
Assert.AreEqual(0, Surrogates.PrevChar("\xD800\xDC00c", 2), "double move succeeds at start (and end)");
Assert.AreEqual(0, Surrogates.PrevChar("\xDC00c", 1), "no double move on bad trailer at start");
Assert.AreEqual(0, Surrogates.PrevChar("\xD800c", 1), "no double move on bad leader at start");
}
[TestCase("\xD800\xDC00c", 2, Result = 0)] // double move succeeds at start (and end)
public int PrevChar(string st, int ich)
{
return(Surrogates.PrevChar(st, ich));
}
[TestCase(new[] { '\xD800', 'c' }, 1, Result = 0)] // no double move on bad leader at start
public int PrevChar_InvalidChar(char[] st, int ich)
{
// NUnit doesn't allow tests with invalid strings in a testcase, so we create the
// string from the character array when running the test
return(Surrogates.PrevChar(new string(st), ich));
}
public int NextChar(string st, int ich)
{
return(Surrogates.NextChar(st, ich));
}
