/*
* ----------------------------------------------------------------------------
* parseFormat()
*
* Parse format string into format tokens (alphanumeric) and separators
* (non-alphanumeric).
*
*/
private static List <FormatInfo> ParseFormat(string formatString)
{
if (formatString == null || formatString.Length == 0)
{
return(null);
}
int length = 0;
bool lastAlphaNumeric = CharUtil.IsAlphaNumeric(formatString[length]);
List <FormatInfo> tokens = new List <FormatInfo>();
int count = 0;
if (lastAlphaNumeric)
{
// If the first one is alpha num add empty separator as a prefix.
tokens.Add(null);
}
while (length <= formatString.Length)
{
// Loop until a switch from format token to separator is detected (or vice-versa)
bool currentchar = length < formatString.Length ? CharUtil.IsAlphaNumeric(formatString[length]) : !lastAlphaNumeric;
if (lastAlphaNumeric != currentchar)
{
FormatInfo formatInfo = new FormatInfo();
if (lastAlphaNumeric)
{
// We just finished a format token. Map it to a numbering format ID and a min-length bound.
mapFormatToken(formatString, count, length - count, out formatInfo.numSequence, out formatInfo.length);
}
else
{
formatInfo.isSeparator = true;
// We just finished a separator. Save its length and a pointer to it.
formatInfo.formatString = formatString.Substring(count, length - count);
}
count = length;
length++;
// Begin parsing the next format token or separator
tokens.Add(formatInfo);
// Flip flag from format token to separator (or vice-versa)
lastAlphaNumeric = currentchar;
}
else
{
length++;
}
}
return(tokens);
}