From 9742e019d9b1394161c880f6f9b55e259c2b71c3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=C3=A9a=20Saviot?= <lea.saviot@numworks.com>
Date: Mon, 8 Jul 2019 09:47:16 +0200
Subject: [PATCH] [poincare/multiplication] Handle non reduced matrices in
 shallowReduce

---
 poincare/src/multiplication.cpp  | 20 ++++++++++++--------
 poincare/test/multiplication.cpp |  1 +
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/poincare/src/multiplication.cpp b/poincare/src/multiplication.cpp
index c3c8bf636..5e420db30 100644
--- a/poincare/src/multiplication.cpp
+++ b/poincare/src/multiplication.cpp
@@ -261,7 +261,7 @@ Expression Multiplication::denominator(Context * context, Preferences::ComplexFo
 
 Expression Multiplication::privateShallowReduce(ExpressionNode::ReductionContext reductionContext, bool shouldExpand, bool canBeInterrupted) {
   {
-    Expression e = Expression::defaultShallowReduce();;
+    Expression e = Expression::defaultShallowReduce();
     if (e.isUndefined()) {
       return e;
     }
@@ -275,9 +275,8 @@ Expression Multiplication::privateShallowReduce(ExpressionNode::ReductionContext
   sortChildrenInPlace([](const ExpressionNode * e1, const ExpressionNode * e2, bool canBeInterrupted) { return ExpressionNode::SimplificationOrder(e1, e2, true, canBeInterrupted); }, reductionContext.context(), true);
 
   // Step 3: Handle matrices
-  /* All children have been simplified so if any child contains a matrix, it
-   * is at the root node of the child. Moreover, thanks to the simplification
-   * order, all matrix children (if any) are the last children. */
+  /* Thanks to the simplification order, all matrix children (if any) are the
+   * last children. */
   Expression lastChild = childAtIndex(numberOfChildren()-1);
   if (lastChild.type() == ExpressionNode::Type::Matrix) {
     Matrix resultMatrix = static_cast<Matrix &>(lastChild);
@@ -343,9 +342,14 @@ Expression Multiplication::privateShallowReduce(ExpressionNode::ReductionContext
       resultMatrix = newResult;
       multiplicationChildIndex--;
     }
-    // Distribute the remaining multiplication children on the matrix children
-    int remainingChildrenCount = numberOfChildren();
-    if (remainingChildrenCount > 1) {
+    /* Distribute the remaining multiplication children on the matrix children,
+     * if there are no oether matrices (such as a non reduced confidence
+     * interval). */
+
+    if (multiplicationChildIndex >= 0) {
+      if (SortedIsMatrix(childAtIndex(multiplicationChildIndex), reductionContext.context())) {
+        return *this;
+      }
       removeChildInPlace(resultMatrix, resultMatrix.numberOfChildren());
       for (int i = 0; i < n*m; i++) {
         Multiplication m = clone().convert<Multiplication>();
@@ -552,7 +556,7 @@ void Multiplication::mergeMultiplicationChildrenInPlace() {
   while (i < numberOfChildren()) {
     Expression c = childAtIndex(i);
     if (c.type() == ExpressionNode::Type::Multiplication) {
-      mergeChildrenAtIndexInPlace(c, numberOfChildren()); // TODO: ensure that matrix children are not swapped to implement MATRIX_EXACT_REDUCING
+      mergeChildrenAtIndexInPlace(c, i); // TODO: ensure that matrix children are not swapped to implement MATRIX_EXACT_REDUCING
       continue;
     }
     i++;
diff --git a/poincare/test/multiplication.cpp b/poincare/test/multiplication.cpp
index f25b9ddde..d953d3e5f 100644
--- a/poincare/test/multiplication.cpp
+++ b/poincare/test/multiplication.cpp
@@ -70,4 +70,5 @@ QUIZ_CASE(poincare_multiplication_simplify) {
   assert_parsed_expression_simplify_to("12^(1/4)×(π/6)×(12×π)^(1/4)", "(√(3)×π^(5/4))/3");
   assert_parsed_expression_simplify_to("[[1,2+𝐢][3,4][5,6]]×[[1,2+𝐢,3,4][5,6+𝐢,7,8]]", "[[11+5×𝐢,13+9×𝐢,17+7×𝐢,20+8×𝐢][23,30+7×𝐢,37,44][35,46+11×𝐢,57,68]]");
   assert_parsed_expression_simplify_to("[[1,2][3,4]]×[[1,3][5,6]]×[[2,3][4,6]]", "[[82,123][178,267]]");
+  assert_parsed_expression_simplify_to("π×confidence(π/5,3)[[1,2]]", "π×confidence(π/5,3)×[[1,2]]");
 }