public Item ParseValue(string instring)
{
// number
if (char.IsDigit(instring[0]))
{
return(new ValueItem(ItemType.Number, double.Parse(instring)));
}
// string
if (instring[0] == '"')
{
return(new ValueItem(
ItemType.String,
instring.Substring(1, instring.Length - 2)));
}
// Type
if (instring[0] == ':')
{
var type = (ItemType)Enum.Parse(typeof(ItemType), instring.Substring(1), true);
return(new TypeItem(type));
}
// symbol
var current = instring;
var quote = false;
if (instring[0] == '\'')
{
current = current.Substring(1);
quote = true;
}
if (char.IsDigit(current.First()))
{
throw new FormatException();
}
var symbol = new SymbolItem(current);
if (quote)
{
symbol.Quote();
}
return(symbol);
}
