public static OperatorExpressionPair Extract(this Expression source, IOperator op, params IToken[] terms)
{
if (!terms.Any())
{
return(null);
}
IOperator oper = op;
int tIndex = source.IndexOf(terms[0]);
InsertOrientation orientation = InsertOrientation.Either;
if (tIndex == 0)
{
if (op.Symbol != '+')
{
source.Remove(op);
}
orientation = InsertOrientation.Right;
}
else
{
source.Remove(op);
orientation = InsertOrientation.Right;
}
oper = Operator.GetInverse(oper);
foreach (IToken term in terms)
{
source.Remove(term);
}
return(new OperatorExpressionPair(oper, new SubExpression(terms), orientation));
}
public OperatorExpressionPair(IOperator oper, SubExpression expr, InsertOrientation orientation)
{
Expr = expr;
Operator = oper;
Orientation = orientation;
}
