# HG changeset patch
# User Peter Kovacs <kpeter@inf.elte.hu>
# Date 2009-04-29 14:25:51
# Node ID 756a5ec551c8ac56edf0c4bca1eb28a4da300b71
# Parent  6c408d864fa1066df1ba3f323b9396d940c9cc19

Rename Flow to Value in the flow algorithms (#266)

We agreed that using Flow for the value type is misleading, since
a flow should be rather a function on the arcs, not a single value.

This patch reverts the changes of [dacc2cee2b4c] for Preflow and
Circulation.

diff --git a/lemon/circulation.h b/lemon/circulation.h
--- a/lemon/circulation.h
+++ b/lemon/circulation.h
@@ -64,15 +64,15 @@
     /// It must conform to the \ref concepts::ReadMap "ReadMap" concept.
     typedef SM SupplyMap;
 
-    /// \brief The type of the flow values.
-    typedef typename SupplyMap::Value Flow;
+    /// \brief The type of the flow and supply values.
+    typedef typename SupplyMap::Value Value;
 
     /// \brief The type of the map that stores the flow values.
     ///
     /// The type of the map that stores the flow values.
     /// It must conform to the \ref concepts::ReadWriteMap "ReadWriteMap"
     /// concept.
-    typedef typename Digraph::template ArcMap<Flow> FlowMap;
+    typedef typename Digraph::template ArcMap<Value> FlowMap;
 
     /// \brief Instantiates a FlowMap.
     ///
@@ -104,7 +104,7 @@
     /// \brief The tolerance used by the algorithm
     ///
     /// The tolerance used by the algorithm to handle inexact computation.
-    typedef lemon::Tolerance<Flow> Tolerance;
+    typedef lemon::Tolerance<Value> Tolerance;
 
   };
 
@@ -187,8 +187,8 @@
     typedef TR Traits;
     ///The type of the digraph the algorithm runs on.
     typedef typename Traits::Digraph Digraph;
-    ///The type of the flow values.
-    typedef typename Traits::Flow Flow;
+    ///The type of the flow and supply values.
+    typedef typename Traits::Value Value;
 
     ///The type of the lower bound map.
     typedef typename Traits::LowerMap LowerMap;
@@ -221,7 +221,7 @@
     Elevator* _level;
     bool _local_level;
 
-    typedef typename Digraph::template NodeMap<Flow> ExcessMap;
+    typedef typename Digraph::template NodeMap<Value> ExcessMap;
     ExcessMap* _excess;
 
     Tolerance _tol;
@@ -530,7 +530,7 @@
           (*_excess)[_g.target(e)] += (*_lo)[e];
           (*_excess)[_g.source(e)] -= (*_lo)[e];
         } else {
-          Flow fc = -(*_excess)[_g.target(e)];
+          Value fc = -(*_excess)[_g.target(e)];
           _flow->set(e, fc);
           (*_excess)[_g.target(e)] = 0;
           (*_excess)[_g.source(e)] -= fc;
@@ -563,11 +563,11 @@
       while((act=_level->highestActive())!=INVALID) {
         int actlevel=(*_level)[act];
         int mlevel=_node_num;
-        Flow exc=(*_excess)[act];
+        Value exc=(*_excess)[act];
 
         for(OutArcIt e(_g,act);e!=INVALID; ++e) {
           Node v = _g.target(e);
-          Flow fc=(*_up)[e]-(*_flow)[e];
+          Value fc=(*_up)[e]-(*_flow)[e];
           if(!_tol.positive(fc)) continue;
           if((*_level)[v]<actlevel) {
             if(!_tol.less(fc, exc)) {
@@ -591,7 +591,7 @@
         }
         for(InArcIt e(_g,act);e!=INVALID; ++e) {
           Node v = _g.source(e);
-          Flow fc=(*_flow)[e]-(*_lo)[e];
+          Value fc=(*_flow)[e]-(*_lo)[e];
           if(!_tol.positive(fc)) continue;
           if((*_level)[v]<actlevel) {
             if(!_tol.less(fc, exc)) {
@@ -661,13 +661,13 @@
 
     ///@{
 
-    /// \brief Returns the flow on the given arc.
+    /// \brief Returns the flow value on the given arc.
     ///
-    /// Returns the flow on the given arc.
+    /// Returns the flow value on the given arc.
     ///
     /// \pre Either \ref run() or \ref init() must be called before
     /// using this function.
-    Flow flow(const Arc& arc) const {
+    Value flow(const Arc& arc) const {
       return (*_flow)[arc];
     }
 
@@ -750,7 +750,7 @@
         if((*_flow)[e]<(*_lo)[e]||(*_flow)[e]>(*_up)[e]) return false;
       for(NodeIt n(_g);n!=INVALID;++n)
         {
-          Flow dif=-(*_supply)[n];
+          Value dif=-(*_supply)[n];
           for(InArcIt e(_g,n);e!=INVALID;++e) dif-=(*_flow)[e];
           for(OutArcIt e(_g,n);e!=INVALID;++e) dif+=(*_flow)[e];
           if(_tol.negative(dif)) return false;
@@ -765,10 +765,10 @@
     ///\sa barrierMap()
     bool checkBarrier() const
     {
-      Flow delta=0;
-      Flow inf_cap = std::numeric_limits<Flow>::has_infinity ?
-        std::numeric_limits<Flow>::infinity() :
-        std::numeric_limits<Flow>::max();
+      Value delta=0;
+      Value inf_cap = std::numeric_limits<Value>::has_infinity ?
+        std::numeric_limits<Value>::infinity() :
+        std::numeric_limits<Value>::max();
       for(NodeIt n(_g);n!=INVALID;++n)
         if(barrier(n))
           delta-=(*_supply)[n];
diff --git a/lemon/network_simplex.h b/lemon/network_simplex.h
--- a/lemon/network_simplex.h
+++ b/lemon/network_simplex.h
@@ -56,10 +56,10 @@
   /// specified, then default values will be used.
   ///
   /// \tparam GR The digraph type the algorithm runs on.
-  /// \tparam F The value type used for flow amounts, capacity bounds
+  /// \tparam V The value type used for flow amounts, capacity bounds
   /// and supply values in the algorithm. By default it is \c int.
   /// \tparam C The value type used for costs and potentials in the
-  /// algorithm. By default it is the same as \c F.
+  /// algorithm. By default it is the same as \c V.
   ///
   /// \warning Both value types must be signed and all input data must
   /// be integer.
@@ -67,23 +67,23 @@
   /// \note %NetworkSimplex provides five different pivot rule
   /// implementations, from which the most efficient one is used
   /// by default. For more information see \ref PivotRule.
-  template <typename GR, typename F = int, typename C = F>
+  template <typename GR, typename V = int, typename C = V>
   class NetworkSimplex
   {
   public:
 
     /// The flow type of the algorithm
-    typedef F Flow;
+    typedef V Value;
     /// The cost type of the algorithm
     typedef C Cost;
 #ifdef DOXYGEN
     /// The type of the flow map
-    typedef GR::ArcMap<Flow> FlowMap;
+    typedef GR::ArcMap<Value> FlowMap;
     /// The type of the potential map
     typedef GR::NodeMap<Cost> PotentialMap;
 #else
     /// The type of the flow map
-    typedef typename GR::template ArcMap<Flow> FlowMap;
+    typedef typename GR::template ArcMap<Value> FlowMap;
     /// The type of the potential map
     typedef typename GR::template NodeMap<Cost> PotentialMap;
 #endif
@@ -206,15 +206,15 @@
 
     TEMPLATE_DIGRAPH_TYPEDEFS(GR);
 
-    typedef typename GR::template ArcMap<Flow> FlowArcMap;
+    typedef typename GR::template ArcMap<Value> ValueArcMap;
     typedef typename GR::template ArcMap<Cost> CostArcMap;
-    typedef typename GR::template NodeMap<Flow> FlowNodeMap;
+    typedef typename GR::template NodeMap<Value> ValueNodeMap;
 
     typedef std::vector<Arc> ArcVector;
     typedef std::vector<Node> NodeVector;
     typedef std::vector<int> IntVector;
     typedef std::vector<bool> BoolVector;
-    typedef std::vector<Flow> FlowVector;
+    typedef std::vector<Value> FlowVector;
     typedef std::vector<Cost> CostVector;
 
     // State constants for arcs
@@ -232,16 +232,16 @@
     int _arc_num;
 
     // Parameters of the problem
-    FlowArcMap *_plower;
-    FlowArcMap *_pupper;
+    ValueArcMap *_plower;
+    ValueArcMap *_pupper;
     CostArcMap *_pcost;
-    FlowNodeMap *_psupply;
+    ValueNodeMap *_psupply;
     bool _pstsup;
     Node _psource, _ptarget;
-    Flow _pstflow;
+    Value _pstflow;
     SupplyType _stype;
     
-    Flow _sum_supply;
+    Value _sum_supply;
 
     // Result maps
     FlowMap *_flow_map;
@@ -278,16 +278,16 @@
     int in_arc, join, u_in, v_in, u_out, v_out;
     int first, second, right, last;
     int stem, par_stem, new_stem;
-    Flow delta;
+    Value delta;
 
   public:
   
     /// \brief Constant for infinite upper bounds (capacities).
     ///
     /// Constant for infinite upper bounds (capacities).
-    /// It is \c std::numeric_limits<Flow>::infinity() if available,
-    /// \c std::numeric_limits<Flow>::max() otherwise.
-    const Flow INF;
+    /// It is \c std::numeric_limits<Value>::infinity() if available,
+    /// \c std::numeric_limits<Value>::max() otherwise.
+    const Value INF;
 
   private:
 
@@ -695,12 +695,12 @@
       _flow_map(NULL), _potential_map(NULL),
       _local_flow(false), _local_potential(false),
       _node_id(graph),
-      INF(std::numeric_limits<Flow>::has_infinity ?
-          std::numeric_limits<Flow>::infinity() :
-          std::numeric_limits<Flow>::max())
+      INF(std::numeric_limits<Value>::has_infinity ?
+          std::numeric_limits<Value>::infinity() :
+          std::numeric_limits<Value>::max())
     {
       // Check the value types
-      LEMON_ASSERT(std::numeric_limits<Flow>::is_signed,
+      LEMON_ASSERT(std::numeric_limits<Value>::is_signed,
         "The flow type of NetworkSimplex must be signed");
       LEMON_ASSERT(std::numeric_limits<Cost>::is_signed,
         "The cost type of NetworkSimplex must be signed");
@@ -725,14 +725,14 @@
     /// will be set to zero on all arcs.
     ///
     /// \param map An arc map storing the lower bounds.
-    /// Its \c Value type must be convertible to the \c Flow type
+    /// Its \c Value type must be convertible to the \c Value type
     /// of the algorithm.
     ///
     /// \return <tt>(*this)</tt>
     template <typename LowerMap>
     NetworkSimplex& lowerMap(const LowerMap& map) {
       delete _plower;
-      _plower = new FlowArcMap(_graph);
+      _plower = new ValueArcMap(_graph);
       for (ArcIt a(_graph); a != INVALID; ++a) {
         (*_plower)[a] = map[a];
       }
@@ -747,14 +747,14 @@
     /// unbounded from above on each arc).
     ///
     /// \param map An arc map storing the upper bounds.
-    /// Its \c Value type must be convertible to the \c Flow type
+    /// Its \c Value type must be convertible to the \c Value type
     /// of the algorithm.
     ///
     /// \return <tt>(*this)</tt>
     template<typename UpperMap>
     NetworkSimplex& upperMap(const UpperMap& map) {
       delete _pupper;
-      _pupper = new FlowArcMap(_graph);
+      _pupper = new ValueArcMap(_graph);
       for (ArcIt a(_graph); a != INVALID; ++a) {
         (*_pupper)[a] = map[a];
       }
@@ -790,7 +790,7 @@
     /// (It makes sense only if non-zero lower bounds are given.)
     ///
     /// \param map A node map storing the supply values.
-    /// Its \c Value type must be convertible to the \c Flow type
+    /// Its \c Value type must be convertible to the \c Value type
     /// of the algorithm.
     ///
     /// \return <tt>(*this)</tt>
@@ -798,7 +798,7 @@
     NetworkSimplex& supplyMap(const SupplyMap& map) {
       delete _psupply;
       _pstsup = false;
-      _psupply = new FlowNodeMap(_graph);
+      _psupply = new ValueNodeMap(_graph);
       for (NodeIt n(_graph); n != INVALID; ++n) {
         (*_psupply)[n] = map[n];
       }
@@ -823,7 +823,7 @@
     /// (i.e. the supply of \c s and the demand of \c t).
     ///
     /// \return <tt>(*this)</tt>
-    NetworkSimplex& stSupply(const Node& s, const Node& t, Flow k) {
+    NetworkSimplex& stSupply(const Node& s, const Node& t, Value k) {
       delete _psupply;
       _psupply = NULL;
       _pstsup = true;
@@ -1025,7 +1025,7 @@
     /// This function returns the flow on the given arc.
     ///
     /// \pre \ref run() must be called before using this function.
-    Flow flow(const Arc& a) const {
+    Value flow(const Arc& a) const {
       return (*_flow_map)[a];
     }
 
@@ -1204,7 +1204,7 @@
       // Remove non-zero lower bounds
       if (_plower) {
         for (int i = 0; i != _arc_num; ++i) {
-          Flow c = (*_plower)[_arc_ref[i]];
+          Value c = (*_plower)[_arc_ref[i]];
           if (c > 0) {
             if (_cap[i] < INF) _cap[i] -= c;
             _supply[_source[i]] -= c;
@@ -1275,7 +1275,7 @@
       }
       delta = _cap[in_arc];
       int result = 0;
-      Flow d;
+      Value d;
       int e;
 
       // Search the cycle along the path form the first node to the root
@@ -1315,7 +1315,7 @@
     void changeFlow(bool change) {
       // Augment along the cycle
       if (delta > 0) {
-        Flow val = _state[in_arc] * delta;
+        Value val = _state[in_arc] * delta;
         _flow[in_arc] += val;
         for (int u = _source[in_arc]; u != join; u = _parent[u]) {
           _flow[_pred[u]] += _forward[u] ? -val : val;
diff --git a/lemon/preflow.h b/lemon/preflow.h
--- a/lemon/preflow.h
+++ b/lemon/preflow.h
@@ -46,13 +46,13 @@
     typedef CAP CapacityMap;
 
     /// \brief The type of the flow values.
-    typedef typename CapacityMap::Value Flow;
+    typedef typename CapacityMap::Value Value;
 
     /// \brief The type of the map that stores the flow values.
     ///
     /// The type of the map that stores the flow values.
     /// It must meet the \ref concepts::ReadWriteMap "ReadWriteMap" concept.
-    typedef typename Digraph::template ArcMap<Flow> FlowMap;
+    typedef typename Digraph::template ArcMap<Value> FlowMap;
 
     /// \brief Instantiates a FlowMap.
     ///
@@ -84,7 +84,7 @@
     /// \brief The tolerance used by the algorithm
     ///
     /// The tolerance used by the algorithm to handle inexact computation.
-    typedef lemon::Tolerance<Flow> Tolerance;
+    typedef lemon::Tolerance<Value> Tolerance;
 
   };
 
@@ -125,7 +125,7 @@
     ///The type of the capacity map.
     typedef typename Traits::CapacityMap CapacityMap;
     ///The type of the flow values.
-    typedef typename Traits::Flow Flow;
+    typedef typename Traits::Value Value;
 
     ///The type of the flow map.
     typedef typename Traits::FlowMap FlowMap;
@@ -151,7 +151,7 @@
     Elevator* _level;
     bool _local_level;
 
-    typedef typename Digraph::template NodeMap<Flow> ExcessMap;
+    typedef typename Digraph::template NodeMap<Value> ExcessMap;
     ExcessMap* _excess;
 
     Tolerance _tolerance;
@@ -470,7 +470,7 @@
       }
 
       for (NodeIt n(_graph); n != INVALID; ++n) {
-        Flow excess = 0;
+        Value excess = 0;
         for (InArcIt e(_graph, n); e != INVALID; ++e) {
           excess += (*_flow)[e];
         }
@@ -519,7 +519,7 @@
       _level->initFinish();
 
       for (OutArcIt e(_graph, _source); e != INVALID; ++e) {
-        Flow rem = (*_capacity)[e] - (*_flow)[e];
+        Value rem = (*_capacity)[e] - (*_flow)[e];
         if (_tolerance.positive(rem)) {
           Node u = _graph.target(e);
           if ((*_level)[u] == _level->maxLevel()) continue;
@@ -531,7 +531,7 @@
         }
       }
       for (InArcIt e(_graph, _source); e != INVALID; ++e) {
-        Flow rem = (*_flow)[e];
+        Value rem = (*_flow)[e];
         if (_tolerance.positive(rem)) {
           Node v = _graph.source(e);
           if ((*_level)[v] == _level->maxLevel()) continue;
@@ -564,11 +564,11 @@
         int num = _node_num;
 
         while (num > 0 && n != INVALID) {
-          Flow excess = (*_excess)[n];
+          Value excess = (*_excess)[n];
           int new_level = _level->maxLevel();
 
           for (OutArcIt e(_graph, n); e != INVALID; ++e) {
-            Flow rem = (*_capacity)[e] - (*_flow)[e];
+            Value rem = (*_capacity)[e] - (*_flow)[e];
             if (!_tolerance.positive(rem)) continue;
             Node v = _graph.target(e);
             if ((*_level)[v] < level) {
@@ -591,7 +591,7 @@
           }
 
           for (InArcIt e(_graph, n); e != INVALID; ++e) {
-            Flow rem = (*_flow)[e];
+            Value rem = (*_flow)[e];
             if (!_tolerance.positive(rem)) continue;
             Node v = _graph.source(e);
             if ((*_level)[v] < level) {
@@ -637,11 +637,11 @@
 
         num = _node_num * 20;
         while (num > 0 && n != INVALID) {
-          Flow excess = (*_excess)[n];
+          Value excess = (*_excess)[n];
           int new_level = _level->maxLevel();
 
           for (OutArcIt e(_graph, n); e != INVALID; ++e) {
-            Flow rem = (*_capacity)[e] - (*_flow)[e];
+            Value rem = (*_capacity)[e] - (*_flow)[e];
             if (!_tolerance.positive(rem)) continue;
             Node v = _graph.target(e);
             if ((*_level)[v] < level) {
@@ -664,7 +664,7 @@
           }
 
           for (InArcIt e(_graph, n); e != INVALID; ++e) {
-            Flow rem = (*_flow)[e];
+            Value rem = (*_flow)[e];
             if (!_tolerance.positive(rem)) continue;
             Node v = _graph.source(e);
             if ((*_level)[v] < level) {
@@ -778,12 +778,12 @@
 
       Node n;
       while ((n = _level->highestActive()) != INVALID) {
-        Flow excess = (*_excess)[n];
+        Value excess = (*_excess)[n];
         int level = _level->highestActiveLevel();
         int new_level = _level->maxLevel();
 
         for (OutArcIt e(_graph, n); e != INVALID; ++e) {
-          Flow rem = (*_capacity)[e] - (*_flow)[e];
+          Value rem = (*_capacity)[e] - (*_flow)[e];
           if (!_tolerance.positive(rem)) continue;
           Node v = _graph.target(e);
           if ((*_level)[v] < level) {
@@ -806,7 +806,7 @@
         }
 
         for (InArcIt e(_graph, n); e != INVALID; ++e) {
-          Flow rem = (*_flow)[e];
+          Value rem = (*_flow)[e];
           if (!_tolerance.positive(rem)) continue;
           Node v = _graph.source(e);
           if ((*_level)[v] < level) {
@@ -897,18 +897,18 @@
     ///
     /// \pre Either \ref run() or \ref init() must be called before
     /// using this function.
-    Flow flowValue() const {
+    Value flowValue() const {
       return (*_excess)[_target];
     }
 
-    /// \brief Returns the flow on the given arc.
+    /// \brief Returns the flow value on the given arc.
     ///
-    /// Returns the flow on the given arc. This method can
+    /// Returns the flow value on the given arc. This method can
     /// be called after the second phase of the algorithm.
     ///
     /// \pre Either \ref run() or \ref init() must be called before
     /// using this function.
-    Flow flow(const Arc& arc) const {
+    Value flow(const Arc& arc) const {
       return (*_flow)[arc];
     }