public override Token TryMatch(ParsingContext context, ISourceStream source)
{
while (true)
{
//Find next position
var newPos = source.IndexOfAny(_stopChars, source.PreviewPosition + 1);
//we either didn't find it
if (newPos == -1)
{
return(context.CreateErrorToken(Resources.ErrNoEndForRegex));// "No end symbol for regex literal."
}
source.PreviewPosition = newPos;
if (source.PreviewChar != EndSymbol)
{
//we hit CR or LF, this is an error
return(context.CreateErrorToken(Resources.ErrNoEndForRegex));
}
if (!CheckEscaped(source))
{
break;
}
}
source.PreviewPosition++; //move after end symbol
//save pattern length, we will need it
var patternLen = source.PreviewPosition - source.Location.Position - 2; //exclude start and end symbol
//read switches and turn them into options
RegexOptions options = RegexOptions.None;
var switches = string.Empty;
while (ReadSwitch(source, ref options))
{
if (IsSet(RegexTermOptions.UniqueSwitches) && switches.Contains(source.PreviewChar))
{
return(context.CreateErrorToken(Resources.ErrDupRegexSwitch, source.PreviewChar)); // "Duplicate switch '{0}' for regular expression"
}
switches += source.PreviewChar.ToString();
source.PreviewPosition++;
}
//check following symbol
if (!IsSet(RegexTermOptions.AllowLetterAfter))
{
var currChar = source.PreviewChar;
if (char.IsLetter(currChar) || currChar == '_')
{
return(context.CreateErrorToken(Resources.ErrInvRegexSwitch, currChar)); // "Invalid switch '{0}' for regular expression"
}
}
var token = source.CreateToken(this.OutputTerminal);
//we have token, now what's left is to set its Value field. It is either pattern itself, or Regex instance
string pattern = token.Text.Substring(1, patternLen); //exclude start and end symbol
object value = pattern;
if (IsSet(RegexTermOptions.CreateRegExObject))
{
value = new Regex(pattern, options);
}
token.Value = value;
token.Details = switches; //save switches in token.Details
return(token);
}
public static string GetRestOfLine(this ISourceStream source, int position)
{
var endIndex = source.IndexOfAny(eol, position);
if (endIndex < 0)
{
endIndex = source.Length;
}
return(source.GetText(position, endIndex - position));
}
private string ReadNotQuotedBody(ParsingContext context, ISourceStream source)
{
var startPos = source.Location.Position;
var sepPos = source.IndexOfAny(_terminators, startPos);
if (sepPos < 0)
{
sepPos = source.Length;
}
source.PreviewPosition = sepPos;
var valueText = source.GetText(startPos, sepPos - startPos);
return(valueText);
}
private Token TryMatchContentExtended(ParsingContext context, ISourceStream source)
{
StringBuilder tokenText = new StringBuilder();
while (true)
{
//Find next position of one of stop chars
var nextPos = source.IndexOfAny(_stopChars, source.PreviewPosition);
if (nextPos == -1)
{
if (IsSet(FreeTextOptions.AllowEof))
{
source.PreviewPosition = source.Length;
return(source.CreateToken(this.OutputTerminal));
}
else
{
return(null);
}
}
var newText = source.GetText(source.PreviewPosition, nextPos - source.PreviewPosition);
tokenText.Append(newText);
source.PreviewPosition = nextPos;
//if it is escape, add escaped text and continue search
if (CheckEscape(source, tokenText))
{
continue;
}
//check terminators
if (CheckTerminators(source, tokenText))
{
break; //from while (true); we reached
}
//The current stop is not at escape or terminator; add this char to token text and move on
tokenText.Append(source.PreviewChar);
source.PreviewPosition++;
}//while
var text = tokenText.ToString();
if (string.IsNullOrEmpty(text) && (this.FreeTextOptions & Parsing.FreeTextOptions.AllowEmpty) == 0)
{
return(null);
}
return(source.CreateToken(this.OutputTerminal, text));
}
private Token CompleteMatch(ParsingContext context, ISourceStream source)
{
//Find end symbol
while (!source.EOF())
{
int firstCharPos;
if (EndSymbols.Count == 1)
{
firstCharPos = source.IndexOf(EndSymbols[0], source.PreviewPosition);
}
else
{
firstCharPos = source.IndexOfAny(_endSymbolsFirsts, source.PreviewPosition);
}
if (firstCharPos < 0)
{
source.PreviewPosition = source.Length;
return(null); //indicating error
}
//We found a character that might start an end symbol; let's see if it is true.
source.PreviewPosition = firstCharPos;
foreach (string endSymbol in EndSymbols)
{
if (source.MatchSymbol(endSymbol))
{
//We found end symbol; eat end symbol only if it is not line comment.
// For line comment, leave LF symbol there, it might be important to have a separate LF token
if (!_isLineComment)
{
source.PreviewPosition += endSymbol.Length;
}
return(source.CreateToken(this.OutputTerminal));
} //if
} //foreach endSymbol
source.PreviewPosition++; //move to the next char and try again
} //while
return(null); //might happen if we found a start char of end symbol, but not the full endSymbol
} //method
public override Token TryMatch(ParsingContext context, ISourceStream source)
{
bool isEscape = source.PreviewChar == EscapeChar && EscapeChar != NoEscape;
if (isEscape)
{
//return a token containing only escaped char
var value = source.NextPreviewChar.ToString();
source.PreviewPosition += 2;
return(source.CreateToken(this.OutputTerminal, value));
}
var stopIndex = source.IndexOfAny(_stopChars, source.Location.Position + 1);
if (stopIndex == source.Location.Position)
{
return(null);
}
if (stopIndex < 0)
{
stopIndex = source.Length;
}
source.PreviewPosition = stopIndex;
return(source.CreateToken(this.OutputTerminal));
} //method
public static int IndexOfAny(this ISourceStream source, char[] anyOf, int index)
{
return(source.IndexOfAny(anyOf, index, source.Length - index));
}