/// <summary>
/// Lex a single line string, if formated value equal null, then drop it and return true.
/// </summary>
/// <param name="LexObject">that string will be Lexd</param>
/// <param name="LexItem">Lex item for Lex string</param>
/// <param name="count">count of Lex result</param>
/// <param name="line">line number</param>
/// <param name="col">column number</param>
/// <returns>match result</returns>
/// <exception cref="ZeroLenghtMatchException">if match zero lenght string</exception>
private bool LexString(ref string LexObject, LexItem LexItem, ref long count, long line, int col)
{
Match match = LexItem.Regex.Match(LexObject);// match reg expr
if (!match.Success)
{
return(false);
}
string result = match.Value;
if (result.Length == 0)
{
throw new ZeroLenghtMatchException(LexItem.Name, LexItem.Regex.ToString(), "Lex Error: Zero Length String Matched, " +
"indicating end-less loop, by Name:" + LexItem.Name + " RegExpr:" + LexItem.Regex.ToString());
}
object value;
if (LexItem.FormatCapText == null)
{
value = result;
}
else
{
value = LexItem.FormatCapText(result); // format the result
}
if (value != null)
{
LexerResult Lexeresult = new LexerResult(count, LexItem.Name, value, line, col); // save the result
// call event to notice user to receive it
if (OnLexedEventHandler?.Invoke(this, Lexeresult) == true)
{
count++; // must be one result for the start with "^" parttern
OnAcceptedEventHandler?.Invoke(this, Lexeresult); // to parse it.
}
}
int restLenght = LexObject.Length - match.Length;
LexObject = LexObject.Substring(match.Length, restLenght);// for continuous operate
return(true);
}
/// <summary>
/// Add a Lex item, and Lex with this order.
/// </summary>
/// <param name="name">Name of item</param>
/// <param name="regExpr">Regular Expression of Lex, and automately add "^" at head</param>
/// <param name="regexOptions">Regular Expression Options</param>
/// <param name="formatCapTextDelegate">The delegate of formatting the result of regExpr</param>
/// <param name="group">LexGroup for advanced usage</param>
/// <exception cref="GroupNumException">if Lex group number is out of limite or under zero</exception>
public void AddLexItem(string name, string regExpr, FormatCapTextDelegate formatCapTextDelegate = null, RegexOptions regexOptions = RegexOptions.None, int group = 0)
{
if (name.Length == 0)
{
return;
}
if (regExpr.Length == 0)
{
return;
}
LexItem LexItem = new LexItem(name, formatCapTextDelegate);
if (!regExpr.StartsWith('^'))
{
regExpr = '^' + regExpr; // reg expr must start from head of string
}
LexItem.SetRegex(regExpr, regexOptions);
if (group >= LexGroupCount || group < 0)
{
throw new GroupNumException(group, "AddLexItem Error: illeagal Lex group number: " + group);
}
LexItems[group].Add(LexItem);
}
