public static Outcome <Iban> TryParse(string value, IbanStyles styles, IbanValidationLevels levels)
{
if (value == null)
{
return(Outcome <Iban> .FromError(Format.Current(Strings.InvalidIbanValue, value)));
}
string input = PreprocessInput(value, styles);
return(from val in IbanParts.TryParse(input)
where IbanValidator.TryValidate(val, levels)
select new Iban(val, levels));
}
public static Iban?Parse(string value, IbanStyles styles, IbanValidationLevels levels)
{
if (value == null)
{
return(null);
}
var val = PreprocessInput(value, styles);
var parts = IbanParts.Parse(val);
if (!parts.HasValue)
{
return(null);
}
if (!IbanValidator.Validate(parts.Value, levels))
{
return(null);
}
return(new Iban(parts.Value, levels));
}
public static Iban?Parse(string value, IbanStyles styles) => Parse(value, styles, IbanValidationLevels.Default);
// NB: Normally, there is either a single whitespace char every four chars or no whitespace
// char at all. Here we are more permissive: multiple whitespaces are ok, and position check
// is not enforced.
private static string PreprocessInput(string text, IbanStyles styles)
{
Debug.Assert(text != null);
// Fast track.
if (styles == IbanStyles.None)
{
return(text);
}
if (text.Length == 0)
{
return(String.Empty);
}
int len = text.Length;
int start = 0;
if (styles.Contains(IbanStyles.AllowLeadingWhite))
{
// Ignore leading whitespaces.
while (start < len)
{
if (text[start] != WHITESPACE_CHAR)
{
break;
}
start++;
}
}
// The input contains only whitespaces.
if (start == len)
{
return(String.Empty);
}
int end = len - 1;
if (styles.Contains(IbanStyles.AllowTrailingWhite))
{
// Ignore trailing whitespaces.
while (end > start)
{
if (text[end] != WHITESPACE_CHAR)
{
break;
}
end--;
}
}
// removespaces is really remove **inner** spaces.
bool removespaces = styles.Contains(IbanStyles.AllowInnerWhite);
if (styles.Contains(IbanStyles.AllowHeader) &&
text.Length >= start + 5 &&
text.Substring(start, 5) == IbanParts.HumanHeader)
{
start += 5;
if (removespaces)
{
// Ignore leading whitespaces.
// By removing an IBAN prefix, we might have white spaces
// again at the beginning of the loop.
while (start < len)
{
if (text[start] != WHITESPACE_CHAR)
{
break;
}
start++;
}
}
}
bool transformcase = styles.Contains(IbanStyles.AllowLowercaseLetter);
// NB: If end - start + 1 < MinLength, the input is clearly invalid, nevertheless
// we continue to process the input until we completely fulfill the method's contract:
// cleanup the input according to the user provided rules.
var output = new char[end - start + 1];
int k = 0;
for (var i = start; i <= end; i++)
{
char ch = text[i];
if (removespaces && i != 0 && i != end && ch == WHITESPACE_CHAR)
{
continue;
}
if (transformcase && ch >= 'a' && ch <= 'z')
{
// NB: We use a known property of the ASCII charset; for instance
// 01100001 = 0x61 = 'a'
// AND 11011111 = 0xDF = ~0x20
// --------
// 01000001 = 0x41 = 'A'
output[k] = (char)(ch & 0xDF);
}
else
{
output[k] = ch;
}
k++;
}
return(new String(output, 0, k));
}
public static Outcome <Iban> TryParse(string value, IbanStyles styles) => TryParse(value, styles, IbanValidationLevels.Default);
// WARNING: This always returns false for IbanStyles.None. public static bool Contains(this IbanStyles @this, IbanStyles styles) => (@this & styles) != 0;
