Move p() and order() into Product

These member functions
replace GetOrder and CalculateProbability non-member functions.

Issue #159

src/fault_tree_analysis.cc

@@ -72,18 +72,14 @@ void Print(const ProductContainer& products) {
   std::cerr << std::flush;
 }
 
-double CalculateProbability(const Product& product) {
+double Product::p() const {
   double p = 1;
-  for (const Literal& literal : product) {
+  for (const Literal& literal : *this) {
     p *= literal.complement ? 1 - literal.event.p() : literal.event.p();
   }
   return p;
 }
 
-int GetOrder(const Product& product) {
-  return product.empty() ? 1 : product.size();
-}
-
 FaultTreeAnalysis::FaultTreeAnalysis(const mef::Gate& root,
                                      const Settings& settings)
     : Analysis(settings),

src/fault_tree_analysis.h

@@ -81,6 +81,16 @@ class Product {
   /// @returns The number of literals in the product.
   int size() const { return data_.size(); }
 
+  /// @returns The order of the product.
+  ///
+  /// @note An empty set indicates the Base/Unity set.
+  int order() const { return empty() ? 1 : size(); }
+
+  /// @returns The product of the literal probabilities.
+  ///
+  /// @pre Events are initialized with expressions.
+  double p() const;
+
   /// @returns A read proxy iterator that points to the first element.
   auto begin() const {
     return boost::make_transform_iterator(data_.begin(),
@@ -167,24 +177,6 @@ class ProductContainer {
 /// @param[in] products  Valid, unique collection of analysis results.
 void Print(const ProductContainer& products);
 
-/// Helper function to compute a Boolean product probability.
-///
-/// @param[in] product  A set of literals.
-///
-/// @returns Product of probabilities of the literals.
-///
-/// @pre Events are initialized with expressions.
-double CalculateProbability(const Product& product);
-
-/// Helper function to determine order of a Boolean product.
-///
-/// @param[in] product  A set of literals.
-///
-/// @returns The order of the product.
-///
-/// @note An empty set is assumed to indicate the Base/Unity set.
-int GetOrder(const Product& product);
-
 /// Fault tree analysis functionality.
 /// The analysis must be done on
 /// a validated and fully initialized fault trees.

src/reporter.cc

@@ -293,13 +293,13 @@ void Reporter::ReportResults(const std::string& ft_name,
   double sum = 0;  // Sum of probabilities for contribution calculations.
   if (prob_analysis) {
     for (const core::Product& product_set : fta.products())
-      sum += CalculateProbability(product_set);
+      sum += product_set.p();
   }
   for (const core::Product& product_set : fta.products()) {
     XmlStreamElement product = sum_of_products.AddChild("product");
-    product.SetAttribute("order", GetOrder(product_set));
+    product.SetAttribute("order", product_set.order());
     if (prob_analysis) {
-      double prob = CalculateProbability(product_set);
+      double prob = product_set.p();
       product.SetAttribute("probability", prob);
       product.SetAttribute("contribution", prob / sum);
     }

tests/risk_analysis_tests.cc

@@ -87,7 +87,7 @@ std::vector<int> RiskAnalysisTest::ProductDistribution() {
   const FaultTreeAnalysis* fta =
       analysis->fault_tree_analyses().begin()->second.get();
   for (const Product& product : fta->products()) {
-    distr[GetOrder(product) - 1]++;
+    distr[product.order() - 1]++;
   }
   while (!distr.empty() && !distr.back())
     distr.pop_back();
@@ -110,8 +110,7 @@ RiskAnalysisTest::product_probability() {
     const FaultTreeAnalysis* fta =
         analysis->fault_tree_analyses().begin()->second.get();
     for (const Product& product : fta->products()) {
-      result_.product_probability.emplace(Convert(product),
-                                          CalculateProbability(product));
+      result_.product_probability.emplace(Convert(product), product.p());
     }
   }
   return result_.product_probability;