Merge Tree branch

apps/tree/addition_node.cpp

@@ -0,0 +1,48 @@
+#include "addition_node.h"
+#include "float_node.h"
+
+bool AdditionNode::shallowReduce() {
+  if (ExpressionNode::shallowReduce()) {
+    return true;
+  }
+  /* Step 1: Addition is associative, so let's start by merging children which
+   * also are additions themselves. */
+  int i = 0;
+  int initialNumberOfChildren = numberOfChildren();
+  while (i < initialNumberOfChildren) {
+    ExpressionNode * currentChild = child(i);
+    if (currentChild->type() == Type::Addition) {
+      TreeRef(this).mergeChildren(TreeRef(currentChild));
+      // Is it ok to modify memory while executing ?
+      continue;
+    }
+    i++;
+  }
+
+  // Step 2: Sort the operands
+  sortChildren();
+
+  /* Step 3: Factorize like terms. Thanks to the simplification order, those are
+   * next to each other at this point. */
+  i = 0;
+  while (i < numberOfChildren()-1) {
+    ExpressionNode * e1 = child(i);
+    ExpressionNode * e2 = child(i+1);
+    if (e1->type() == Type::Float && e2->type() == Type::Float) {
+      float sum = e1->approximate() + e2->approximate();
+      // Remove first e2 then e1, else the pointers change
+      removeChild(e2);
+      removeChild(e1);
+      FloatRef f(sum);
+      addChildAtIndex(f.node(), i);
+      continue;
+    }
+    /*if (TermsHaveIdenticalNonRationalFactors(e1, e2)) { //TODO
+      factorizeOperands(e1, e2); //TODO
+      continue;
+      }*/
+    i++;
+  }
+
+  return false;
+}