1 files changed, 19 insertions, 6 deletions
diff --git a/include/expressions.hpp b/include/expressions.hpp
index b7a2921..3191436 100644
--- a/include/expressions.hpp
+++ b/include/expressions.hpp
@@ -2,10 +2,10 @@
  * FACULTAD DE CIENCIAS FÍSICO MATEMÁTICAS
  * Luis Sebastián Martínez Vega - LCC */
 
-#include <string>
-#include "lexer.hpp"
 #ifndef EXPRESSIONS_H
 #define EXPRESSIONS_H
+#include <string>
+#include "lexer.hpp"
 
 /* Debido a que en eval() llamamos a la respectiva
    función trigonométrica, hay un conflicto entre
@@ -23,14 +23,18 @@ enum trig_functions {
   i_ctg
 };
 
+class Differentiator; // Forward declaration.
+
 class Expression {
 public:
   Expression(Expression *left, Expression *right, token_type type);
   virtual ~Expression() = default;
   std::string getRepr();
-  const Expression *getLeft();
-  const Expression *getRight();
+  Expression *diff(const Differentiator *d);
+  Expression *getLeft();
+  Expression *getRight();
   virtual float eval(int arg) = 0;
+  virtual Expression *copy() = 0; // Regresa una copia de la expresión actual.
 protected:
   Expression *left;
   Expression *right;
@@ -48,6 +52,7 @@ public:
   ~Literal();
   int getValue();
   float eval(int arg) override;
+  Expression *copy() override;
 protected:
   void setRepr() override;
 };
@@ -59,9 +64,10 @@ private:
 public:
   Function(Expression *arg, trig_functions name);
   ~Function();
-  const Expression *getArg();
+  Expression *getArg();
   float eval(int arg) override;
-  trig_functions getFunctionName();
+  trig_functions getFunctionName() const;
+  Expression *copy() override;
 protected:
   void delTree();
   void setRepr() override;
@@ -74,6 +80,7 @@ public:
   explicit Variable(char name);
   ~Variable();
   float eval(int arg) override;
+  Expression *copy() override;
 protected:
   void setRepr() override;
 };
@@ -83,6 +90,7 @@ public:
   AddExpression(Expression *left, Expression *right);
   ~AddExpression();
   float eval(int arg) override;
+  Expression *copy() override;
 };
 
 class SubExpression : public Expression {
@@ -90,6 +98,7 @@ public:
   SubExpression(Expression *left, Expression *right);
   ~SubExpression();
   float eval(int arg) override;
+  Expression *copy() override;
 };
 
 class NegationExpression : public Expression {
@@ -97,6 +106,7 @@ public:
   explicit NegationExpression(Expression *right);
   ~NegationExpression();
   float eval(int arg) override;
+  Expression *copy() override;
 protected:
   void setRepr() override;
 };
@@ -106,6 +116,7 @@ public:
   DivisionExpression(Expression *left, Expression *right);
   ~DivisionExpression();
   float eval(int arg) override;
+  Expression *copy() override;
 };
 
 class MultiplicationExpression : public Expression {
@@ -113,6 +124,7 @@ public:
   MultiplicationExpression(Expression *left, Expression *right);
   ~MultiplicationExpression();
   float eval(int arg) override;
+  Expression *copy() override;
 };
 
 class PowerExpression : public Expression {
@@ -120,6 +132,7 @@ public:
   PowerExpression(Expression *left, Expression *right);
   ~PowerExpression();
   float eval(int arg) override;
+  Expression *copy() override;
 };
 
 #endif /* EXPRESSIONS_H */