internal static ParsingResult TryParse(string input, Scale scale, out ChordProgression chordProgression) { chordProgression = null; if (string.IsNullOrWhiteSpace(input)) { return(ParsingResult.EmptyInputString); } var matches = ParsingUtilities.Matches(input, Patterns, ignoreCase: false); if (matches == null) { return(ParsingResult.NotMatched); } var chords = new List <Chord>(); foreach (var match in matches) { var degreeGroup = match.Groups[ScaleDegreeGroupName]; var degreeRoman = degreeGroup.Value.ToLower(); if (string.IsNullOrWhiteSpace(degreeRoman)) { continue; } var degree = RomanToInteger(degreeRoman); var rootNoteName = scale.GetStep(degree - 1); var fullString = match.Value; var matchIndex = match.Index; var degreeGroupIndex = degreeGroup.Index; var chordString = fullString.Substring(0, degreeGroupIndex - matchIndex) + rootNoteName + fullString.Substring(degreeGroupIndex - matchIndex + degreeGroup.Length); Chord chord; var chordParsingResult = ChordParser.TryParse(chordString, out chord); if (chordParsingResult.Status != ParsingStatus.Parsed) { return(chordParsingResult); } chords.Add(chord); } chordProgression = new ChordProgression(chords); return(ParsingResult.Parsed); }