# HG changeset patch
# User alpar
# Date 1082207753 0
# Node ID b63ea19e502eb9795373c1b05aef2af73a79125a
# Parent  e4ab32225f1cfddbd2b0434368284987a1fec095
A bool Edge Map with iterators that goes through the true or the false edges.

diff -r e4ab32225f1c -r b63ea19e502e src/work/alpar/boolmap_iter.cc
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/work/alpar/boolmap_iter.cc	Sat Apr 17 13:15:53 2004 +0000
@@ -0,0 +1,131 @@
+#include <iostream>
+#include <vector>
+#include <smart_graph.h>
+
+using namespace hugo;
+
+///\todo This is only a static map!
+///
+template<class GG>
+class BoolIterEdgeMap
+{
+public:
+  typedef GG Graph;
+  typedef typename GG::Edge Edge;
+  
+  typedef Edge KeyType;
+  typedef bool ValueType;
+  
+  friend class RefType;
+  friend class FalseIterator;
+  friend class TrueIterator;
+
+private:
+  Graph &G;
+  typename Graph::EdgeMap<int> cref;
+  std::vector<Edge> vals;
+  int sep;           //map[e] is true <=> cref[e]>=sep
+  
+  bool isTrue(Edge e) {return cref[e]>=sep;}
+  void swap(Edge e, int s) 
+  {
+    int ti=cref[e];
+    Edge te=vals[s];
+    cref[e]=s; vals[s]=e;
+    cref[te]=ti; vals[ti]=te;
+  }  
+
+  void setTrue(Edge e) { if(cref[e]<sep) { sep--; swap(e,sep); } }
+  void setFalse(Edge e) { if(cref[e]>=sep) { swap(e,sep); sep++; } }
+  
+public:
+  class FalseIterator 
+  {
+    BoolIterEdgeMap &M;
+    int i;
+  public:
+    FalseIterator(BoolIterEdgeMap &_M) : M(_M), i(0) { }
+    FalseIterator &operator++() { ++i; return *this;}
+    operator Edge() { return i<M.sep ? M.vals[i] : INVALID; }
+    operator bool() { return i<M.sep; }
+  };
+  class TrueIterator 
+  {
+    BoolIterEdgeMap &M;
+    int i;
+  public:
+    TrueIterator(BoolIterEdgeMap &_M) : M(_M), i(M.vals.size()-1) { }
+    TrueIterator &operator++() { --i; return *this;}
+    operator Edge() { return i>=M.sep ? M.vals[i] : INVALID; }
+    operator bool() { return i>=M.sep; }
+  };
+  
+  class RefType 
+  {
+    BoolIterEdgeMap &M;
+    Edge e;
+  public:
+    RefType(BoolIterEdgeMap &_M,Edge _e) : M(_M), e(_e) { }
+    
+    operator ValueType() const 
+    {
+      return M.isTrue(e);
+      
+    }
+    ValueType operator = (ValueType v) const
+    {
+      if(v) M.setTrue(e); 
+      else M.setFalse(e);
+      return v;
+    }
+  };
+  
+public:
+  BoolIterEdgeMap(Graph &_G) : G(_G), cref(G)
+  {
+    sep=0;
+    for(typename Graph::EdgeIt e(G);G.valid(e);G.next(e)) {
+      cref[e]=sep;
+      vals.push_back(e);
+      sep++;
+    }
+  }
+  RefType operator[] (Edge e) { return RefType(*this,e);}  
+};
+
+int main()
+{
+  typedef SmartGraph Graph;
+  typedef Graph::NodeIt NodeIt;
+  typedef Graph::OutEdgeIt OutEdgeIt;
+  typedef Graph::EdgeIt EdgeIt;
+  
+  Graph G;
+
+  for(int i=0;i<3;i++) G.addNode();
+
+  for(NodeIt n(G);G.valid(n);G.next(n))
+    for(NodeIt m(G);G.valid(m);G.next(m)) if(n!=m)
+      G.addEdge(n,m);
+
+  //for(OutEdgeIt e(G,NodeIt(G));G.valid(e);G.next(e))
+    
+  BoolIterEdgeMap<Graph> map(G);
+
+  bool b=true;
+  
+  for(EdgeIt e(G);G.valid(e);G.next(e)) {map[e]=b;b=!b;}
+  
+  std::cout << true << '\n';
+
+  for(EdgeIt e(G);G.valid(e);G.next(e))
+    std::cout << G.id(G.tail(e)) << "->" << G.id(G.head(e))
+      << ": " << map[e] << '\n';
+  std::cout << "True Edges:\n";
+  for(BoolIterEdgeMap<Graph>::TrueIterator i(map);i;++i)
+    std::cout << G.id(G.tail(i)) << "->" << G.id(G.head(i)) << '\n';
+  std::cout << "False Edges:\n";
+  for(BoolIterEdgeMap<Graph>::FalseIterator i(map);i;++i)
+    std::cout << G.id(G.tail(i)) << "->" << G.id(G.head(i)) << '\n';
+}
+