/// <summary>
/// Convert an integral number to it's written form.
/// </summary>
/// <param name="number">
/// The number to convert
/// </param>
/// <returns>
/// A string representing the input number in words
/// </returns>
protected virtual string ConvertIntegral(long number)
{
string buffer = number.ToString();
StringBuilder words = new StringBuilder();
bool isTenOnes = false;
List <int> lastDigits = new List <int>();
for (int i = 0; i < buffer.Length; i++)
{
Digit digit = new Digit(buffer, i);
if ((digit.digit == 1) && (digit.basePlaceValue == BasePlaceValue.Tens))
{
isTenOnes = true;
continue;
}
string word = ComposeWord(digit, isTenOnes, lastDigits);
lastDigits.Add(digit.digit);
if (digit.basePlaceValue == BasePlaceValue.Ones)
{
lastDigits.Clear();
}
if (word.Length > 0)
{
words.Append(word);
words.Append(" ");
}
isTenOnes = false;
}
return(words.ToString().Trim());
}
/// <summary>
/// Compose a word from a digit
/// </summary>
/// <param name="digit">
/// Information about a digit within a string
/// </param>
/// <param name="isTenOnes">
/// Whether the function should produce a number n, such that n ∈ {10, ..., 19}
/// </param>
/// <param name="lastDigits">
/// A list of last digits in a BasePlaceValue
/// If a digit has a Ones BasePlaceValue then lastDigits will contain the 2 previous digits if there were any
/// </param>
protected abstract string ComposeWord(Digit digit, bool isTenOnes, List <int> lastDigits);
/// <summary>
/// See <c>AConverter.ComposeWord</c> documentation
/// </summary>
protected override string ComposeWord(Digit digit, bool isTensOnes, List <int> lastDigits)
{
string word = "";
if (isTensOnes)
{
word = TensOnes[digit.digit];
word += " " + composeBigPlaceValueExtensionWord(MAX_EXTENSION_VALUE, digit.bigPlaceValue);
}
else
{
switch (digit.basePlaceValue)
{
case BasePlaceValue.Ones:
int lastDigit = lastDigits.FirstOrDefault();
bool shouldShowDigit = lastDigit > 0 || digit.digit > 1 || digit.bigPlaceValue == BigPlaceValue.None;
if (shouldShowDigit)
{
word = Ones[digit.digit];
}
int extensionValue;
if (digit.digit <= 1 && lastDigits.Sum() > 0)
{
extensionValue = MAX_EXTENSION_VALUE;
}
else
{
extensionValue = digit.digit;
}
string bigPlaceValueWord = composeBigPlaceValueExtensionWord(extensionValue, digit.bigPlaceValue);
if (bigPlaceValueWord.Length > 0)
{
if (digit.digit > 0)
{
word += " ";
}
word += bigPlaceValueWord;
}
break;
case BasePlaceValue.Tens:
word = (composeTensWord(digit.digit));
break;
case BasePlaceValue.Hundrends:
word = composeHundredsWord(digit.digit);
break;
default:
break;
}
}
return(word);
}