[poincare] implement isRationalZero for other numbers

Change-Id: I40f61958f9e51adb376407b2a512097962979417

poincare/include/poincare/based_integer.h

@@ -28,6 +28,7 @@ public:
   // Expression subclassing
   Type type() const override { return Type::BasedInteger; }
   Sign sign(Context * context) const override { return Sign::Positive; }
+  bool isRationalZero() const override { return integer().isZero(); }
 
   // Layout
   Layout createLayout(Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const override;

poincare/include/poincare/decimal.h

@@ -43,6 +43,7 @@ public:
   Type type() const override { return Type::Decimal; }
   Sign sign(Context * context) const override { return m_negative ? Sign::Negative : Sign::Positive; }
   Expression setSign(Sign s, ReductionContext reductionContext) override;
+  bool isRationalZero() const override { return unsignedMantissa().isZero(); }
 
   // Approximation
   Evaluation<float> approximate(SinglePrecision p, Context * context, Preferences::ComplexFormat complexFormat, Preferences::AngleUnit angleUnit) const override {

poincare/include/poincare/expression.h

@@ -153,7 +153,7 @@ public:
   ExpressionNode::Sign sign(Context * context) const { return node()->sign(context); }
   bool isUndefined() const { return node()->type() == ExpressionNode::Type::Undefined ||  node()->type() == ExpressionNode::Type::Unreal; }
   bool isNumber() const { return node()->isNumber(); }
-  bool isRationalZero() const;
+  bool isRationalZero() const { return node()->isRationalZero(); }
   bool isRationalOne() const;
   bool isRandom() const { return node()->isRandom(); }
   bool isParameteredExpression() const { return node()->isParameteredExpression(); }

poincare/include/poincare/expression_node.h

@@ -187,6 +187,7 @@ public:
 
   virtual Sign sign(Context * context) const { return Sign::Unknown; }
   virtual bool isNumber() const { return false; }
+  virtual bool isRationalZero() const { return false; }
   virtual bool isRandom() const { return false; }
   virtual bool isParameteredExpression() const { return false; }
   /* childAtIndexNeedsUserParentheses checks if parentheses are required by mathematical rules:

poincare/include/poincare/float.h

@@ -40,6 +40,7 @@ public:
   Sign sign(Context * context) const override { return m_value < 0 ? Sign::Negative : Sign::Positive; }
   Expression setSign(Sign s, ReductionContext reductionContext) override;
   int simplificationOrderSameType(const ExpressionNode * e, bool ascending, bool canBeInterrupted, bool ignoreParentheses) const override;
+  bool isRationalZero() const override { return m_value == 0.0; }
 
   // Layout
   int serialize(char * buffer, int bufferSize, Preferences::PrintFloatMode floatDisplayMode, int numberOfSignificantDigits) const override;

poincare/include/poincare/rational.h

@@ -17,6 +17,7 @@ public:
   bool isNegative() const { return m_negative; }
   void setNegative(bool negative) { m_negative = negative; }
   bool isInteger() const { return denominator().isOne(); }
+  bool isRationalZero() const override { return isZero(); }
 
   // TreeNode
   size_t size() const override;

poincare/src/expression.cpp

@@ -79,10 +79,6 @@ Expression Expression::childAtIndex(int i) const {
 
 /* Properties */
 
-bool Expression::isRationalZero() const {
-  return type() == ExpressionNode::Type::Rational && convert<const Rational>().isZero();
-}
-
 bool Expression::isRationalOne() const {
   return type() == ExpressionNode::Type::Rational && convert<const Rational>().isOne();
 }