public override double Evaluate(Parser parser, Interpreter ii)
{
if (_token.Identifier == MathTokenType.Swap)
{
var left = _left as NameExpression;
var right = _right as NameExpression;
if (left == null) throw new ProcessusException(parser.Source, _token, "Left side of swap operation was not a variable.");
if (right == null) throw new ProcessusException(parser.Source, _token, "Right side of swap operation was not a variable.");
double temp = left.Evaluate(parser, ii);
double b = right.Evaluate(parser, ii);
ii.Engine.Variables.SetVar(left.Name, b);
ii.Engine.Variables.SetVar(right.Name, temp);
return b;
}
Func<Parser, Interpreter, NameExpression, Expression, double> assignFunc;
if (AssignOperations.TryGetValue(_token.Identifier, out assignFunc))
{
var left = _left as NameExpression;
if (left == null) throw new ProcessusException(parser.Source, _token, "Left side of assignment was not a variable.");
return assignFunc(parser, ii, left, _right);
}
Func<double, double, double> func;
if (!Operations.TryGetValue(_token.Identifier, out func))
{
throw new ProcessusException(parser.Source, _token, "Invalid binary operation '" + _token + "'.");
}
return func(_left.Evaluate(parser, ii), _right.Evaluate(parser, ii));
}
public override double Evaluate(Parser parser, Interpreter ii)
{
var name = _left as NameExpression;
if (name == null)
{
throw new ProcessusException(parser.Source, _token, "Left side of increment/decrement postfix was not a variable.");
}
switch (_token.Identifier)
{
case MathTokenType.Increment:
{
double d = name.Evaluate(parser, ii);
ii.Engine.Variables.SetVar(name.Name, d + 1);
return d;
}
case MathTokenType.Decrement:
{
double d = name.Evaluate(parser, ii);
ii.Engine.Variables.SetVar(name.Name, d - 1);
return d;
}
default:
throw new ProcessusException(parser.Source, _token, "Invalid postfix operator '" + _token.Value + "'.");
}
}
public override double Evaluate(Parser parser, Interpreter ii)
{
var name = _right as NameExpression;
switch (_token.Identifier)
{
case MathTokenType.Minus:
return -_right.Evaluate(parser, ii);
case MathTokenType.Increment:
{
if (name == null)
{
throw new ProcessusException(parser.Source, _token, "Increment prefix could not find a variable.");
}
double d = name.Evaluate(parser, ii) + 1;
ii.Engine.Variables.SetVar(name.Name, d);
return d;
}
case MathTokenType.Decrement:
{
if (name == null)
{
throw new ProcessusException(parser.Source, _token, "Decrement prefix could not find a variable.");
}
double d = name.Evaluate(parser, ii) - 1;
ii.Engine.Variables.SetVar(name.Name, d);
return d;
}
default:
throw new ProcessusException(parser.Source, _token, "Invalid prefix operator '" + _token + "'.");
}
}
public static double Calculate(Interpreter ii, string expression)
{
double result = 0;
foreach (var expr in expression.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries))
{
var p = new Parser(new Lexer(expr.ToStringe()));
result = p.ParseExpression().Evaluate(p, ii);
}
return result;
}
public override double Evaluate(Parser parser, Interpreter ii)
{
return _number;
}
public override double Evaluate(Parser parser, Interpreter ii)
{
var d = ii.Engine.Variables.GetVar(_name.Value);
if (d == null) throw new ProcessusException(parser.Source, _name, "Tried to access undefined variable '" + _name.Value + "'.");
return d.Value;
}
public abstract double Evaluate(Parser parser, Interpreter ii);