protected IOperand GetOperand <T>() where T : IConvertible
{
string text = "";
IOperand output = null;
scanner.SkipWhitespace();
if (scanner.Current == '-')
{
// convert leading - to "-1" if it precedes a variable, otherwise
// just add it to the output stream
scanner.Next();
if (scanner.Finished)
{
throw new ArgumentException("Unexpected end of string found, expected an operand (a number or variable name)");
}
if (CharacterData.IsType(scanner.Current, CharacterType.Number))
{
text += "-";
}
else
{
output = new Literal <T>(-1);
}
}
else if (scanner.Current == '+')
{
// ignore leading +
scanner.Next();
}
if (output == null)
{
if (scanner.Info.Numeric)
{
text += scanner.Get(MatchFunctions.Number());
double num;
if (Double.TryParse(text, out num))
{
output = IsTyped ? new Literal <T>(num) : new Literal(num);
}
else
{
throw new InvalidCastException("Unable to parse number from '" + text + "'");
}
}
else if (scanner.Info.Alpha)
{
text += scanner.GetAlpha();
if (scanner.CurrentOrEmpty == "(")
{
IFunction func = Utils.GetFunction <T>(text);
var inner = scanner.ExpectBoundedBy('(', true).ToNewScanner("{0},");
while (!inner.Finished)
{
string parm = inner.Get(MatchFunctions.BoundedBy(boundEnd: ","));
EquationParserEngine innerParser = new EquationParserEngine();
IOperand innerOperand = innerParser.Parse <T>(parm);
func.AddOperand(innerOperand);
}
CacheVariables(func);
output = func;
}
else
{
IVariable var = GetVariable <T>(text);
output = var;
}
}
else if (scanner.Current == '(')
{
string inner = scanner.Get(MatchFunctions.BoundedBy("("));
var parser = new EquationParserEngine();
parser.Parse <T>(inner);
output = parser.Clause;
CacheVariables(output);
}
else
{
throw new ArgumentException("Unexpected character '" + scanner.Match + "' found, expected an operand (a number or variable name)");
}
}
scanner.SkipWhitespace();
ParseEnd = scanner.Finished;
return(output);
}
protected IOperand GetOperand <T>() where T : IConvertible
{
string text;
IOperand output;
scanner.SkipWhitespace();
if (scanner.Info.NumericExtended)
{
text = scanner.Get(MatchFunctions.Number());
double num;
if (Double.TryParse(text, out num))
{
output = IsTyped ? new Literal <T>(num) : new Literal(num);
}
else
{
throw new InvalidCastException("Unable to parse number from '" + text + "'");
}
}
else if (scanner.Info.Alpha)
{
text = scanner.GetAlpha();
if (scanner.NextCharOrEmpty == "(")
{
IFunction func = Utils.GetFunction <T>(text);
var inner = scanner.ExpectBoundedBy('(', true).ToNewScanner("{0},");
while (!inner.Finished)
{
string parm = inner.Get(MatchFunctions.BoundedBy(boundEnd: ","));
EquationParser innerParser = new EquationParser();
IOperand innerOperand = innerParser.Parse <T>(parm);
func.AddOperand(innerOperand);
}
CacheVariables(func);
output = func;
}
else
{
IVariable var = GetVariable <T>(text);
output = var;
}
}
else if (scanner.NextChar == '(')
{
string inner = scanner.Get(MatchFunctions.BoundedBy("("));
var parser = new EquationParser();
parser.Parse <T>(inner);
output = parser.Clause;
CacheVariables(output);
}
else
{
throw new InvalidOperationException("Unexpected character '" + scanner.Match + "' found, expected an operand (a number or variable name)");
}
scanner.SkipWhitespace();
ParseEnd = scanner.Finished;
return(output);
}
