/// <summary>
/// Adds a factor.
/// eg. {2, x^2}, {4} + {-3, y}, {2}
/// </summary>
/// <param name="factor"></param>
public void Add(Factor factor)
{
Factor rFactor = this;
Factor lFactor = factor;
Factor result = new Factor ();
if (lFactor.Terms.Count > 0)
for (int i = lFactor.Terms.Count - 1; i >= 0; i--) {
bool done = false;
if (rFactor.Terms.Count > 0)
for (int j = rFactor.Terms.Count - 1; j >= 0; j--) {
if (lFactor.Terms [i].VariablesToString ().Equals (rFactor.Terms [j].VariablesToString ())) {
lFactor.Terms [i].Coefficient += rFactor.Terms [j].Coefficient;
if (lFactor.Terms [i].Coefficient != 0)
result.Add (lFactor.Terms [i]);
lFactor.Terms.RemoveAt (i);
rFactor.Terms.RemoveAt (j);
done = true;
break;
}
}
if (!done) {
result.Add (lFactor.Terms [i]);
lFactor.Terms.RemoveAt (i);
}
}
if (rFactor.Terms.Count > 0)
foreach (var rTerm in rFactor.Terms) {
result.Add (rTerm);
}
this.Terms = result.Terms;
}
// TermOp -> * SignedFactor TermOp
// TermOp -> / SignedFactor TermOp
// TermOp -> EPSILON
Factor TermOp(Factor factor)
{
switch (lookahead.type) {
case TokenType.MULTI:
GetNextToken ();
factor.Multiply (SignedFactor ());
return TermOp (factor);
case TokenType.DEV:
GetNextToken ();
factor.Divide (SignedFactor ());
return TermOp (factor);
default:
return factor;
}
}
//SumOp -> + Term SumOp
//SumOp -> - Term SumOp
//SumOp -> EPSILON
Factor SumOp(Factor t)
{
Factor t2;
switch (lookahead.type) {
case TokenType.ADD:
GetNextToken ();
t2 = Term ();
t.Add (t2);
return SumOp (t);
case TokenType.SUB:
GetNextToken ();
t2 = Term ();
t.Subtract (t2);
return SumOp (t);
default:
return t;
}
}
public Factor(Factor factor)
{
Terms = factor.Terms;
}
/// <summary>
/// Subtracts a factor.
/// eg. {2, x^2}, {4} - {-3, y}, {2}
/// </summary>
/// <param name="factor"></param>
public void Subtract(Factor factor)
{
foreach (var f in factor.Terms)
f.Coefficient *= -1;
Add (factor);
}
/// <summary>
/// Multiply a factor by a factor.
/// (2x + 1) * (x + 3)
/// </summary>
/// <param name="factor"></param>
public void Multiply(Factor factor)
{
Factor result = new Factor ();
Factor rTerm;
foreach (var f in Terms) {
rTerm = factor.Clone ();
rTerm.Multiply (f);
result.Add (rTerm);
}
Terms = result.Terms;
}
/// <summary>
/// Divide by a factor.
/// eg. (2x + 1) / (3x + 2)
/// </summary>
/// <param name="t">The factor to be devided by.</param>
public void Divide(Factor t)
{
Factor result = new Factor ();
Factor rTerm;
foreach (var factor in Terms) {
rTerm = t.Clone ();
rTerm.Divide (factor);
result.Add (rTerm);
}
Terms = result.Terms;
}
public Factor Clone()
{
Factor t = new Factor ();
foreach (var factor in Terms) {
t.Terms.Add (factor.Clone ());
}
return t;
}