public Expression ReturnSubtraction(Expression expr)
{
if (expr is FunctionExpression)
{
FunctionExpression fexpr = (FunctionExpression)expr;
IList<Expression> args = new List<Expression>();
foreach (Expression arg in fexpr.Arguments)
args.Add(Return(arg));
return Expression.Function(fexpr.Name, args);
}
else if (expr is BinaryExpression)
{
BinaryExpression bexpr = (BinaryExpression)expr;
Expression left = ReturnSubtraction(bexpr.Left);
Expression right = ReturnSubtraction(bexpr.Right);
Expression oleft = left;
Expression oright = right;
if (bexpr.Operator == Binary.Multiply || bexpr.Operator == Binary.Divide)
{
/*
bool negative = false;
NumberExpression number = null;
bool isLeft = false;
if (left is NumberExpression && ((NumberExpression)left).Value < 0)
{
negative = true;
nleft = Expression.Number(((NumberExpression)left).Value * -1);
isLeft = true;
number = (NumberExpression)nleft;
}
else if (right is NumberExpression && ((NumberExpression)right).Value < 0)
{
negative = true;
nright = Expression.Number(((NumberExpression)right).Value * -1);
number = (NumberExpression)nright;
}
if (left is NegativeExpression || right is NegativeExpression)
negative = !negative;
if (left is NegativeExpression)
{
nleft = ((NegativeExpression)nleft).Value;
left = ((NegativeExpression)left).Original;
}
else if (right is NegativeExpression)
{
nright = ((NegativeExpression)nright).Value;
right = ((NegativeExpression)right).Original;
}
Expression toReturn = null;
if (number != null && number.Value == 1 && (bexpr.Operator == Binary.Multiply || bexpr.Operator == Binary.Divide && !isLeft))
{
if (isLeft)
toReturn = nright;
else
toReturn = nleft;
}
else
toReturn = Expression.FromBinary(bexpr.Operator, nleft, nright);
if (!negative)
return toReturn;
return new NegativeExpression(toReturn, Expression.FromBinary(bexpr.Operator, left, right));
*/
bool negative = false;
if (left is NegativeExpression)
{
negative = !negative;
oleft = ((NegativeExpression)left).Original;
left = ((NegativeExpression)left).Value;
}
if (right is NegativeExpression)
{
negative = !negative;
oright = ((NegativeExpression)right).Original;
right = ((NegativeExpression)right).Value;
}
Expression full = null;
if (left is NumberExpression && ((NumberExpression)left).Value == 1 && bexpr.Operator == Binary.Multiply)
full = right;
else if (right is NumberExpression && ((NumberExpression)right).Value == 1 && (bexpr.Operator == Binary.Multiply || bexpr.Operator == Binary.Divide))
full = left;
else
full = Expression.FromBinary(bexpr.Operator, left, right);
if (negative)
full = new NegativeExpression(full, Expression.FromBinary(bexpr.Operator, oleft, oright));
return full;
}
else if (bexpr.Operator == Binary.Add && (left is NegativeExpression || right is NegativeExpression))
{
if (!(left is NegativeExpression) && right is NegativeExpression)
return Expression.Subtract(left, ((NegativeExpression)right).Value);
else if (left is NegativeExpression && !(right is NegativeExpression))
return Expression.Subtract(right, ((NegativeExpression)left).Value);
else
return Expression.Subtract(((NegativeExpression)left).Original, ((NegativeExpression)right).Value);
}
return Expression.FromBinary(bexpr.Operator, left, right);
}
else if (expr is NumberExpression)
{
NumberExpression nexpr = (NumberExpression)expr;
if (nexpr.Value < 0)
return new NegativeExpression(Expression.Number(-1 * nexpr.Value), nexpr);
return nexpr;
}
return expr;
}
public Expression ReturnSubtraction(Expression expr)
{
if (expr is FunctionExpression)
{
FunctionExpression fexpr = (FunctionExpression)expr;
IList <Expression> args = new List <Expression>();
foreach (Expression arg in fexpr.Arguments)
{
args.Add(Return(arg));
}
return(Expression.Function(fexpr.Name, args));
}
else if (expr is BinaryExpression)
{
BinaryExpression bexpr = (BinaryExpression)expr;
Expression left = ReturnSubtraction(bexpr.Left);
Expression right = ReturnSubtraction(bexpr.Right);
Expression oleft = left;
Expression oright = right;
if (bexpr.Operator == Binary.Multiply || bexpr.Operator == Binary.Divide)
{
/*
* bool negative = false;
*
* NumberExpression number = null;
* bool isLeft = false;
*
* if (left is NumberExpression && ((NumberExpression)left).Value < 0)
* {
* negative = true;
* nleft = Expression.Number(((NumberExpression)left).Value * -1);
*
* isLeft = true;
* number = (NumberExpression)nleft;
* }
* else if (right is NumberExpression && ((NumberExpression)right).Value < 0)
* {
* negative = true;
* nright = Expression.Number(((NumberExpression)right).Value * -1);
*
* number = (NumberExpression)nright;
* }
*
* if (left is NegativeExpression || right is NegativeExpression)
* negative = !negative;
*
* if (left is NegativeExpression)
* {
* nleft = ((NegativeExpression)nleft).Value;
* left = ((NegativeExpression)left).Original;
* }
* else if (right is NegativeExpression)
* {
* nright = ((NegativeExpression)nright).Value;
* right = ((NegativeExpression)right).Original;
* }
*
* Expression toReturn = null;
*
* if (number != null && number.Value == 1 && (bexpr.Operator == Binary.Multiply || bexpr.Operator == Binary.Divide && !isLeft))
* {
* if (isLeft)
* toReturn = nright;
* else
* toReturn = nleft;
* }
* else
* toReturn = Expression.FromBinary(bexpr.Operator, nleft, nright);
*
* if (!negative)
* return toReturn;
*
* return new NegativeExpression(toReturn, Expression.FromBinary(bexpr.Operator, left, right));
*/
bool negative = false;
if (left is NegativeExpression)
{
negative = !negative;
oleft = ((NegativeExpression)left).Original;
left = ((NegativeExpression)left).Value;
}
if (right is NegativeExpression)
{
negative = !negative;
oright = ((NegativeExpression)right).Original;
right = ((NegativeExpression)right).Value;
}
Expression full = null;
if (left is NumberExpression && ((NumberExpression)left).Value == 1 && bexpr.Operator == Binary.Multiply)
{
full = right;
}
else if (right is NumberExpression && ((NumberExpression)right).Value == 1 && (bexpr.Operator == Binary.Multiply || bexpr.Operator == Binary.Divide))
{
full = left;
}
else
{
full = Expression.FromBinary(bexpr.Operator, left, right);
}
if (negative)
{
full = new NegativeExpression(full, Expression.FromBinary(bexpr.Operator, oleft, oright));
}
return(full);
}
else if (bexpr.Operator == Binary.Add && (left is NegativeExpression || right is NegativeExpression))
{
if (!(left is NegativeExpression) && right is NegativeExpression)
{
return(Expression.Subtract(left, ((NegativeExpression)right).Value));
}
else if (left is NegativeExpression && !(right is NegativeExpression))
{
return(Expression.Subtract(right, ((NegativeExpression)left).Value));
}
else
{
return(Expression.Subtract(((NegativeExpression)left).Original, ((NegativeExpression)right).Value));
}
}
return(Expression.FromBinary(bexpr.Operator, left, right));
}
else if (expr is NumberExpression)
{
NumberExpression nexpr = (NumberExpression)expr;
if (nexpr.Value < 0)
{
return(new NegativeExpression(Expression.Number(-1 * nexpr.Value), nexpr));
}
return(nexpr);
}
return(expr);
}