public static IValue ParseValue(string text, int sectionCharIndex, ParsingStatus status)
{
// split the text to parse in its W-value components
var textParts = text.Split(new char[] { ',' });
int currentIndex = 0;
var register = new FullWordRegister();
var word = new FullWord(0);
// parse and apply each component to the word that contains the result
foreach (string part in textParts)
{
// parse the address part...
var braceIndex = part.IndexOf('(');
var address = ExpressionValue.ParseValue((braceIndex == -1) ? part : part.Substring(0, braceIndex), sectionCharIndex + currentIndex, status);
if (address == null)
{
return(null);
}
// ... and check if it is valid
var addressSign = address.GetSign(status.LocationCounter);
var addressMagnitude = address.GetMagnitude(status.LocationCounter);
if (addressMagnitude > register.MaxMagnitude)
{
status.ReportParsingError(sectionCharIndex + currentIndex, (braceIndex == -1) ? part.Length : braceIndex, "W-value field value invalid");
return(null);
}
register.MagnitudeLongValue = addressMagnitude;
register.Sign = addressSign;
int fieldValue = FullWord.ByteCount;
// if a fieldspec part is present...
if (braceIndex >= 0)
{
// ... parse its value...
var field = FPartValue.ParseValue(part.Substring(braceIndex), (sectionCharIndex + currentIndex) + braceIndex, status);
if (field == null)
{
return(null);
}
// ... and check if it is valid
if (field.GetValue(status.LocationCounter) != FPartValue.Default)
{
fieldValue = (int)field.GetValue(status.LocationCounter);
}
}
// use the fieldspec value to create and check an actual fieldspec
var fieldSpec = new FieldSpec(fieldValue);
if (!fieldSpec.IsValid)
{
status.ReportParsingError((sectionCharIndex + currentIndex) + braceIndex, part.Length - braceIndex, "field must be a fieldspec");
return(null);
}
// apply the component to the word that will contain the end result
WordField.LoadFromRegister(fieldSpec, register).ApplyToFullWord(word);
currentIndex += part.Length + 1;
}
return(new NumberValue(word.Sign, word.MagnitudeLongValue));
}
