How do you correctly handle strings with embedded escaped quotes?

Hi,

I am trying to parse a language that allows strings with embedded quotes represented by C-style escapes:

"Embedded \"quote\""

Largely by pattern matching, I have created a programmable lexer with the following code:

            // Initialize the PrimaryString lexical state.

            lexicalState = lexicalStates["PrimaryString"];
            lexicalState.DefaultClassificationType = classificationTypeProvider.String;
            lexicalState.DefaultTokenId = NXSLTokenId.StringText;
            lexicalState.DefaultTokenKey = "StringText";
            DynamicLexicalScope lexicalScope = new DynamicLexicalScope();
            lexicalState.LexicalScopes.Add(lexicalScope);

            lexicalPatternGroup = new DynamicLexicalPatternGroup(DynamicLexicalPatternType.Explicit, "StringStartDelimiter", null)
            {
                TokenId = NXSLTokenId.StringStartDelimiter
            };
            lexicalPatternGroup.Patterns.Add(new DynamicLexicalPattern("\""));
            lexicalPatternGroup.Patterns.Add(new DynamicLexicalPattern("#\""));
            lexicalScope.StartLexicalPatternGroup = lexicalPatternGroup;

            lexicalPatternGroup = new DynamicLexicalPatternGroup(DynamicLexicalPatternType.Explicit, "StringEndDelimiter", null)
            {
                TokenId = NXSLTokenId.StringEndDelimiter
            };
            lexicalPatternGroup.Patterns.Add(new DynamicLexicalPattern("\""));
            lexicalScope.EndLexicalPatternGroup = lexicalPatternGroup;

            lexicalPatternGroup = new DynamicLexicalPatternGroup(DynamicLexicalPatternType.Regex, "StringLineTerminator", null)
            {
                TokenId = NXSLTokenId.StringLineTerminator
            };
            lexicalPatternGroup.Patterns.Add(new DynamicLexicalPattern("\\n"));
            lexicalState.LexicalPatternGroups.Add(lexicalPatternGroup);

            lexicalPatternGroup = new DynamicLexicalPatternGroup(DynamicLexicalPatternType.Explicit, "StringEscapedDelimiter", null)
            {
                TokenId = NXSLTokenId.StringEscapedDelimiter
            };
            lexicalPatternGroup.Patterns.Add(new DynamicLexicalPattern("\\\""));
            lexicalState.LexicalPatternGroups.Add(lexicalPatternGroup);

            lexicalPatternGroup = new DynamicLexicalPatternGroup(DynamicLexicalPatternType.Regex, "StringText", null)
            {
                TokenId = NXSLTokenId.StringText
            };
            lexicalPatternGroup.Patterns.Add(new DynamicLexicalPattern("[^\\\"\\\\\\n]+"));
            lexicalState.LexicalPatternGroups.Add(lexicalPatternGroup);

 It is quite possible that my mistake is in the grammar, which looks like this:

            var @openQuote  = new Terminal(NXSLTokenId.StringStartDelimiter, "OpenQuote")   { ErrorAlias = "'\"'" };
            var @string     = new Terminal(NXSLTokenId.StringText,           "StringText");
            var @closeQuote = new Terminal(NXSLTokenId.StringEndDelimiter,   "CloseQuote")  { ErrorAlias = "'\"'" };

            primaryExpression.Production = idExpression
                | builtinExpression
                | parenExpression
                | curlyExpression
                | @openQuote + @string.Optional() + @closeQuote
                | @real
                | @integer
                | @false
                | @true;

Unfortunately, I get an error every time I use a \" in a string. The error is '"': expected.

I would greatly appreciate any suggestions regarding possible misuses of the grammar and/or lexer.

Thanks in advance,

Scott Haney