From f326f16ffbeb2a06d3017a0576eb564772d8ec1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89milie=20Feral?= <emilie.feral@numworks.com>
Date: Thu, 6 Sep 2018 14:06:21 +0200
Subject: [PATCH] [solver] Fix Equation with new Poincare APi

---
 apps/solver/equation.cpp          | 29 ++++++++++++-----------------
 apps/solver/equation.h            |  4 ++--
 poincare/include/poincare/equal.h |  4 ++--
 poincare/src/equal.cpp            | 10 +++++-----
 4 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/apps/solver/equation.cpp b/apps/solver/equation.cpp
index 91420d39b..b32b288d7 100644
--- a/apps/solver/equation.cpp
+++ b/apps/solver/equation.cpp
@@ -6,7 +6,7 @@ namespace Solver {
 
 Equation::Equation() :
   Shared::ExpressionModel(),
-  m_standardForm(nullptr)
+  m_standardForm()
 {
 }
 
@@ -27,33 +27,28 @@ void Equation::setContent(const char * c) {
 
 void Equation::tidy() {
   ExpressionModel::tidy();
-  if (m_standardForm) {
-    delete m_standardForm;
-    m_standardForm = nullptr;
-  }
+  tidyStandardForm();
 }
 
-Expression * Equation::standardForm(Context * context) const {
-  if (m_standardForm == nullptr) {
-    Expression * e = expression(context);
-    if (e->type() == ExpressionNode::Type::Equal) {
-      m_standardForm = static_cast<const Equal *>(e)->standardEquation(*context, Preferences::sharedPreferences()->angleUnit());
-    } else if (e->type() == ExpressionNode::Type::Rational && static_cast<Rational *>(e)->isOne()) {
+Expression Equation::standardForm(Context * context) const {
+  if (m_standardForm.isUninitialized()) {
+    const Expression e = expression(context);
+    if (e.type() == ExpressionNode::Type::Equal) {
+      m_standardForm = static_cast<const Equal&>(e).standardEquation(*context, Preferences::sharedPreferences()->angleUnit());
+    } else if (e.type() == ExpressionNode::Type::Rational && static_cast<const Rational&>(e).isOne()) {
       // The equality was reduced which means the equality was always true.
-      m_standardForm = RationalReference(0);
+      m_standardForm = Rational(0);
     } else {
       // The equality has an undefined operand
-      assert(e->type() == ExpressionNode::Type::Undefined);
+      assert(e.type() == ExpressionNode::Type::Undefined);
     }
   }
   return m_standardForm;
 }
 
 void Equation::tidyStandardForm() {
-  if (m_standardForm) {
-    delete m_standardForm;
-    m_standardForm = nullptr;
-  }
+  // Free the pool of the m_standardForm
+  m_standardForm = Expression();
 }
 
 }
diff --git a/apps/solver/equation.h b/apps/solver/equation.h
index c888314d5..c4a7c1c63 100644
--- a/apps/solver/equation.h
+++ b/apps/solver/equation.h
@@ -18,10 +18,10 @@ public:
   bool shouldBeClearedBeforeRemove() override {
     return false;
   }
-  Poincare::Expression * standardForm(Poincare::Context * context) const;
+  Poincare::Expression standardForm(Poincare::Context * context) const;
 private:
   void tidyStandardForm();
-  mutable Poincare::Expression * m_standardForm;
+  mutable Poincare::Expression m_standardForm;
 };
 
 }
diff --git a/poincare/include/poincare/equal.h b/poincare/include/poincare/equal.h
index 170dca933..b50bf750c 100644
--- a/poincare/include/poincare/equal.h
+++ b/poincare/include/poincare/equal.h
@@ -20,8 +20,6 @@ public:
   // ExpressionNode
   Type type() const override { return Type::Equal; }
   int polynomialDegree(char symbolName) const override { return -1; }
-  // For the equation A = B, create the reduced expression A-B
-  Expression standardEquation(Context & context, Preferences::AngleUnit angleUnit) const;
 private:
   // Simplification
   Expression shallowReduce(Context & context, Preferences::AngleUnit angleUnit) override;
@@ -42,6 +40,8 @@ public:
     replaceChildAtIndexInPlace(1, child2);
   }
 
+  // For the equation A = B, create the reduced expression A-B
+  Expression standardEquation(Context & context, Preferences::AngleUnit angleUnit) const;
   // Expression
   Expression shallowReduce(Context & context, Preferences::AngleUnit angleUnit);
 };
diff --git a/poincare/src/equal.cpp b/poincare/src/equal.cpp
index a13a2bd62..4adebe95e 100644
--- a/poincare/src/equal.cpp
+++ b/poincare/src/equal.cpp
@@ -19,11 +19,6 @@ extern "C" {
 }
 namespace Poincare {
 
-Expression EqualNode::standardEquation(Context & context, Preferences::AngleUnit angleUnit) const {
-  Expression sub = Subtraction(Expression(childAtIndex(0)).clone(), Expression(childAtIndex(1)).clone());
-  return sub.deepReduce(context, angleUnit);
-}
-
 Expression EqualNode::shallowReduce(Context & context, Preferences::AngleUnit angleUnit) {
   return Equal(this).shallowReduce(context, angleUnit);
 }
@@ -45,6 +40,11 @@ Evaluation<T> EqualNode::templatedApproximate(Context& context, Preferences::Ang
   return Complex<T>::Undefined();
 }
 
+Expression Equal::standardEquation(Context & context, Preferences::AngleUnit angleUnit) const {
+  Expression sub = Subtraction(childAtIndex(0).clone(), childAtIndex(1).clone());
+  return sub.deepReduce(context, angleUnit);
+}
+
 Expression Equal::shallowReduce(Context & context, Preferences::AngleUnit angleUnit) {
   {
     Expression e = Expression::defaultShallowReduce(context, angleUnit);