public override bool TryParse(Scanner scanner, out ChordFingeringNode result)
{
result = new ChordFingeringNode();
var anchor = scanner.MakeAnchor();
var remainingLine = scanner.RemainingLine.Trim();
var containsDelimiter = remainingLine.Any(char.IsWhiteSpace);
var containsFingerIndexSpecifier = remainingLine.Any(c => c == '<' || c == '>');
var isShortForm = !containsDelimiter && !containsFingerIndexSpecifier;
while (!_terminatorPredicate(scanner))
{
var noteAnchor = scanner.MakeAnchor();
var str = isShortForm ? scanner.ReadPattern(@"[\dxX\-]") : scanner.ReadAnyPatternOf(@"\d+", @"[xX\-]");
if (string.IsNullOrEmpty(str))
{
this.Report(LogLevel.Warning, scanner.LastReadRange,
Messages.Error_ChordFingeringInvalidFingering);
result = null;
return(false);
}
switch (str)
{
case "x":
case "X":
case "-":
{
var fret = new LiteralNode <int>(Chord.FingeringSkipString, scanner.LastReadRange);
result.Fingerings.Add(new ChordFingeringNoteNode {
Fret = fret, Range = scanner.LastReadRange
});
break;
}
default:
int fretNumber;
if (!int.TryParse(str, out fretNumber)) // todo: prevent too large fret number
{
this.Report(LogLevel.Warning, scanner.LastReadRange,
Messages.Error_ChordFingeringInvalidFingering);
result = null;
return(false);
}
if (fretNumber > 24)
{
this.Report(LogLevel.Warning, scanner.LastReadRange,
Messages.Warning_ChordFingeringFretTooHigh);
}
var note = new ChordFingeringNoteNode
{
Fret = new LiteralNode <int>(fretNumber, scanner.LastReadRange),
Range = scanner.LastReadRange
};
if (fretNumber != 0)
{
scanner.SkipWhitespaces();
if (scanner.Expect('<'))
{
scanner.SkipWhitespaces();
var fingerIndexString = scanner.ReadPattern(@"[\dtT]");
if (string.IsNullOrEmpty(fingerIndexString))
{
this.Report(LogLevel.Error, scanner.Pointer.AsRange(),
Messages.Error_ChordFingerIndexExpected);
return(false);
}
LeftHandFingerIndex fingerIndex;
switch (fingerIndexString)
{
case "t":
case "T":
fingerIndex = LeftHandFingerIndex.Thumb; break;
case "1":
fingerIndex = LeftHandFingerIndex.Index; break;
case "2":
fingerIndex = LeftHandFingerIndex.Middle; break;
case "3":
fingerIndex = LeftHandFingerIndex.Ring; break;
case "4":
fingerIndex = LeftHandFingerIndex.Pinky; break;
default:
this.Report(LogLevel.Error, scanner.LastReadRange,
Messages.Error_UnrecognizableFingerIndex);
return(false);
}
note.FingerIndex = new LiteralNode <LeftHandFingerIndex>(fingerIndex,
scanner.LastReadRange);
scanner.SkipWhitespaces();
ExistencyNode importancy;
if (new CharExistencyParser('!').TryParse(scanner, out importancy))
{
note.Importancy = importancy;
scanner.SkipWhitespaces();
}
if (!scanner.Expect('>'))
{
this.Report(LogLevel.Error, scanner.Pointer.AsRange(),
Messages.Error_ChordFingerIndexNotEnclosed);
return(false);
}
}
}
note.Range = noteAnchor.Range;
result.Fingerings.Add(note);
break;
}
scanner.SkipWhitespaces();
}
if (result.Fingerings.Count != Defaults.Strings)
{
this.Report(LogLevel.Error, scanner.LastReadRange,
Messages.Error_ChordFingeringNotMatchingStringCount, Defaults.Strings);
result = null;
return(false);
}
result.Range = anchor.Range;
return(true);
}