Añadido código de las reglas, solucionado errores.

1 files changed, 46 insertions, 10 deletions

diff --git a/differentiator.cpp b/differentiator.cpp
index 739c19a..d25366d 100644
--- a/differentiator.cpp
+++ b/differentiator.cpp
@@ -11,17 +11,17 @@ Differentiator::Differentiator() {
 }
 
 // Regla del constante. f(x)=c, f'(x)=0.
-Expression *Differentiator::visit(Literal *expr) {
+Expression *Differentiator::visit(Literal *expr) const {
   return new Literal(0);
 }
 
 // Regla de la variable. f(x)=x, f'(x)=1
-Expression *Differentiator::visit(Variable *expr) {
+Expression *Differentiator::visit(Variable *expr) const {
   return new Literal(1);
 }
 
 // Reglas de funciones trigonométricas.
-Expression *Differentiator::visit(Function *expr) {
+Expression *Differentiator::visit(Function *expr) const {
   Expression *diff;
   
   switch (expr->getFunctionName()) {
@@ -56,22 +56,58 @@ Expression *Differentiator::visit(Function *expr) {
   }
 }
 
-Expression *Differentiator::visit(NegationExpression *expr) {
-  return new NegationExpression(expr->diff(this));
+// Regla de la negación. (La derivada del lado derecho.)
+Expression *Differentiator::visit(NegationExpression *expr) const {
+  return new NegationExpression(expr->getRight()->diff(this));
 }
 
-Expression *Differentiator::visit(AddExpression *expr) {
+// Regla de la suma (las derivadas del lado izquierdo y derecho).
+Expression *Differentiator::visit(AddExpression *expr) const {
   return new AddExpression(expr->getLeft()->diff(this), expr->getRight()->diff(this));
 }
 
-Expression *Differentiator::visit(SubExpression *expr) {
+/* Regla de la resta. Igual que la de la suma, pero restando los derivandos
+   en vez de sumarlos. */
+Expression *Differentiator::visit(SubExpression *expr) const {
   return new SubExpression(expr->getLeft()->diff(this), expr->getRight()->diff(this));
 }
 
 // Regla de la potencia. f(x)=x^c, f'(x)=c*x^(c-1)}*f'(x).
-Expression *Differentiator::visit(PowerExpression *expr) {
+Expression *Differentiator::visit(PowerExpression *expr) const {
   Literal *c = dynamic_cast<Literal *>(expr->getRight());
-
-  return new MultiplicationExpression(new MultiplicationExpression(c->copy(), new PowerExpression(expr->getLeft()->copy(), new Literal(c->getValue() - 1))),
+  Variable *x = dynamic_cast<Variable *>(expr->getLeft());
+  
+  /* Si el valor izquierdo no es un número, entonces el derecho
+     lo es. */
+  if(c == NULL) {
+    c = dynamic_cast<Literal *>(expr->getLeft());
+    x = dynamic_cast<Variable *>(expr->getRight());
+  }
+  
+  return new MultiplicationExpression(new MultiplicationExpression(c->copy(), new PowerExpression(x->copy(), new Literal(c->getValue() - 1))),
 				      expr->getLeft()->diff(this));
 }
+
+// Regla del producto.
+Expression *Differentiator::visit(MultiplicationExpression *expr) const {
+  Expression *u = expr->getLeft();
+  Expression *v = expr->getRight();
+
+  return new AddExpression(new MultiplicationExpression(u->copy(), v->diff(this)), new MultiplicationExpression(v->copy(), u->diff(this)));
+}
+
+// Regla de la división.
+Expression *Differentiator::visit(DivisionExpression *expr) const {
+  Expression *u = expr->getLeft();
+  Expression *v = expr->getRight();
+
+  return new DivisionExpression(new SubExpression(new MultiplicationExpression(v->copy(), u->diff(this)),
+						  new MultiplicationExpression(u->copy(), v->diff(this))), new PowerExpression(v->copy(), new Literal(2)));
+}
+
+// Función wrapper.
+Expression *deriv(Expression *to_deriv) {
+  Differentiator d;
+
+  return to_deriv->diff(&d);
+}