public AssignExpressionNode(AssignOperations operation, WritableNode left, ExpressionNode value, SourceSpan sourceSpan)
: base(sourceSpan)
{
this.operation = operation;
this.left = left;
this.value = value;
}
public override double Evaluate(MathParser parser, VM ii)
{
if (_token.ID == RMathToken.Swap)
{
var left = _left as NameExpression;
var right = _right as NameExpression;
if (left == null)
{
throw new RantException(parser.Source, _token, "Left side of swap operation was not a variable.");
}
if (right == null)
{
throw new RantException(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 <MathParser, VM, NameExpression, Expression, double> assignFunc;
if (AssignOperations.TryGetValue(_token.ID, out assignFunc))
{
var left = _left as NameExpression;
if (left == null)
{
throw new RantException(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.ID, out func))
{
throw new RantException(parser.Source, _token, "Invalid binary operation '" + _token + "'.");
}
return(func(_left.Evaluate(parser, ii), _right.Evaluate(parser, ii)));
}
