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copied!<p>First, you are obviously using some kind of parsing library, you would have better chance if you had modified your code, e.g. to something like I did, so that anybody can copy, paste, run your code.</p> <p>Answer is simple, your (string literal)-parsing region does not parse all input. Here is your code modified to be used without any additional library:</p> <pre><code>public class Test { static char ElementAtOrDefault(string value, int position) { return position >= value.Length ? default(char) : value[position]; } static string parseStringLiteral(string value, ref int ChPosition) { StringBuilder Value = new StringBuilder(); char ChCurrent = ElementAtOrDefault(value, ++ChPosition); while (ChCurrent != '"') { Value.Append(ChCurrent); ChCurrent = ElementAtOrDefault(value, ++ChPosition); if (ChCurrent == '"') { // "" sequence only acceptable if (ElementAtOrDefault(value, ChPosition + 1) == '"') { Value.Append(ChCurrent); // skip 2nd double quote ChPosition++; // move position next ChCurrent = ElementAtOrDefault(value, ++ChPosition); } } else if (default(Char) == ChCurrent) { // message: unterminated string throw new Exception("ScanningException"); } } ChPosition++; return Value.ToString(); } public static void test(string literal) { Console.WriteLine("testing literal with " + literal.Length + " chars:\n" + literal); try { int pos = 0; string res = parseStringLiteral(literal, ref pos); Console.WriteLine("Parsed " + res.Length + " chars:\n" + res); } catch (Exception ex) { Console.WriteLine("Error: " + ex.Message); } Console.WriteLine(); } public static int Main(string[] args) { test(@"""Hello Language Design"""); test(@"""Is there any problems with the """"strings""""?"""); test(@"""v#:';?325;.<>,|+_)""(*&^%$#@![]{}\|-_="""); return 0; } } </code></pre> <p>Running this program produces output:</p> <pre>testing literal with 23 chars: "Hello Language Design" Parsed 21 chars: Hello Language Design testing literal with 45 chars: "Is there any problems with the ""strings""?" Parsed 41 chars: Is there any problems with the "strings"? testing literal with 39 chars: "v#:';?325;.,|+_)"(*&^%$#@![]{}\|-_=" Parsed 18 chars: v#:';?325;.,|+_)</pre> <p>So it works for your testing, but algorithm is not correct, try running:</p> <pre><code>//literal with "", should produce ", but it does not test(@""""""""""); </code></pre> <p>And you will incorrectly get:</p> <pre>testing literal with 4 chars: """" Parsed 0 chars:</pre> <p>Problem is, if you encounter character " in your while condition, you do not check next character, if it is " or not:</p> <pre><code>while (ChCurrent != '"') //bug </code></pre> <p>Of course, I created correct version for you :-) Here it is (it uses your style, just edited version of yours):</p> <pre><code>static string parseStringLiteral(string value, ref int ChPosition) { StringBuilder Value = new StringBuilder(); char ChCurrent = ElementAtOrDefault(value, ++ChPosition); bool goon = true; while (goon) { if (ChCurrent == '"') { // "" sequence only acceptable if (ElementAtOrDefault(value, ChPosition + 1) == '"') { Value.Append(ChCurrent); // skip 2nd double quote ChPosition++; // move position next ChCurrent = ElementAtOrDefault(value, ++ChPosition); } else goon = false; //break; } else if (default(Char) == ChCurrent) { // message: unterminated string throw new Exception("ScanningException"); } else { Value.Append(ChCurrent); ChCurrent = ElementAtOrDefault(value, ++ChPosition); } } ChPosition++; return Value.ToString(); } </code></pre> <p>Happy coding :-)</p>

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