public override bool VisitMultiply(TExpr left, TExpr right, TExpr original, Dummy data)
{
Polynomial <TVar, TExpr> l, r;
var lBuilt = Build(left, out l);
var rBuilt = Build(right, out r);
if (lBuilt && rBuilt)
{
long kLeft, kRight;
object mult;
if (l.IsIntConstant(out kLeft) && r.IsIntConstant(out kRight) &&
EvaluateArithmeticWithOverflow.TryBinary(
Decoder.TypeOf(original), ExpressionOperator.Mult, kLeft, kRight, out mult))
{
var longValue = mult.ConvertToLong();
if (longValue.HasValue)
{
var monomial = Monomial <TVar> .From(Rational.For(longValue.Value));
return(true.With(new Polynomial <TVar, TExpr> (monomial), out poly));
}
}
return(TryToPolynomialHelperForMultiplication(l, r, out poly));
}
return(false);
}
static bool TryEvaluateInt32 (BinaryOperator op, int l, int r, out long value)
{
int result;
if (EvaluateArithmeticWithOverflow.TryBinary (op.ToExpressionOperator (), l, r,
out result))
return true.With (result, out value);
return false.Without (out value);
}
public override bool VisitSubtraction(TExpr left, TExpr right, TExpr original, Dummy data)
{
Polynomial <TVar, TExpr> polyLeft, polyRight;
if (!Build(left, out polyLeft) || !Build(right, out polyRight))
{
return(false);
}
long kLeft, kRight;
object subtraction;
if (polyLeft.IsIntConstant(out kLeft) && polyRight.IsIntConstant(out kRight) &&
EvaluateArithmeticWithOverflow.TryBinary(Decoder.TypeOf(original), ExpressionOperator.Sub, kLeft, kRight, out subtraction))
{
var longValue = subtraction.ConvertToLong();
if (longValue.HasValue)
{
return(true.With(new Polynomial <TVar, TExpr> (Monomial <TVar> .From(Rational.For(longValue.Value))), out poly));
}
}
return(TryToPolynomialHelperForSubtraction(polyLeft, polyRight, out poly));
}