Add multiplication rules.

Change-Id: I5e91414e8c6ad45e0ff2d19fc7c5dc3914fa247a

poincare/src/simplify/rules.pr

@@ -3,3 +3,5 @@ Addition(Integer.a,Integer.b)->$AddIntegers(a,b);
 Addition(Integer.a,Integer.b,c*)->Addition($AddIntegers(a,b),c*);
 Product(Product(a*),b*)->Product(a*,b*);
 Product(Integer[0],a*)->Integer[0];
+Product(Integer.a,Integer.b)->$MultiplyIntegers(a,b);
+Product(Integer.a,Integer.b,c*)->Product($MultiplyIntegers(a,b),c*);

poincare/src/simplify/simplification_generator.cpp

@@ -8,8 +8,22 @@ Expression * SimplificationGenerator::AddIntegers(Expression ** parameters, int
   Integer * result = new Integer((native_int_t)0);
   for (int i=0; i<numberOfParameters; i++) {
     assert(parameters[i]->type() == Expression::Type::Integer);
-    // FIXME: get rid of this operator overloading.
-    *result = *result + *(Integer *)parameters[i];
+    *result = result->add(*(Integer *)parameters[i], false);
+    /* Note We have to delete the parameters as they have been cloned before and
+     * we are the last ones to use them here. */
+    delete parameters[i];
+  }
+  return result;
+}
+
+Expression * SimplificationGenerator::MultiplyIntegers(Expression ** parameters, int numberOfParameters) {
+  Integer * result = new Integer((native_int_t)1);
+  for (int i=0; i<numberOfParameters; i++) {
+    assert(parameters[i]->type() == Expression::Type::Integer);
+    // FIXME: get rid of this operator overloading, there are to many stars.
+    *result = *result * *(Integer *)parameters[i];
+    /* Note We have to delete the parameters as they have been cloned before and
+     * we are the last ones to use them here. */
     delete parameters[i];
   }
   return result;

poincare/src/simplify/simplification_generator.h

@@ -6,6 +6,7 @@
 class SimplificationGenerator {
 public:
   static Expression * AddIntegers(Expression ** parameters, int numberOfParameters);
+  static Expression * MultiplyIntegers(Expression ** parameters, int numberOfParameters);
 };
 
 #endif

poincare/test/simplify_product.cpp

@@ -5,6 +5,12 @@
 QUIZ_CASE(poincare_simplify_product_by_zero) {
   assert(simplifies_to("3*0", "0"));
   assert(simplifies_to("foo*0", "0"));
+
   assert(simplifies_to("0*3", "0"));
   assert(simplifies_to("0*foo", "0"));
+
+  assert(simplifies_to("3*5", "15"));
+  assert(simplifies_to("8*6", "48"));
+
+  assert(simplifies_to("3*(5+4)", "27"));
 }