From b7eaa99578037789a337c5061c0ea8ee3150b63c Mon Sep 17 00:00:00 2001
From: "Zancanaro; Carlo" <czan8762@plang3.cs.usyd.edu.au>
Date: Thu, 1 Nov 2012 18:06:13 +1100
Subject: A bunch of fixes to the solver, and moving it in to clang.

Also some contribution writing stuff.

Basically: lots of work.
---
 impl/MaxStrategy.hpp | 55 ++++++++++++++--------------------------------------
 1 file changed, 15 insertions(+), 40 deletions(-)

(limited to 'impl/MaxStrategy.hpp')

diff --git a/impl/MaxStrategy.hpp b/impl/MaxStrategy.hpp
index 71ea4f4..6fee921 100644
--- a/impl/MaxStrategy.hpp
+++ b/impl/MaxStrategy.hpp
@@ -20,7 +20,7 @@ unsigned int stack_depth = 1;
 std::string indent() {
   std::string result = "";
   for (unsigned int i = 0; i < stack_depth; ++i) {
-    result += '\t';
+    result += ' ';
   }
   return result;
 }
@@ -39,22 +39,13 @@ struct DynamicMaxStrategy : public MaxStrategy<Domain> {
       _values(system.maxExpressionCount(), 0),
       _stable(system.maxExpressionCount()),
       _influence(system.maxExpressionCount(),
-                 IdSet<MaxExpression<Domain> >(system.maxExpressionCount())),
-      _changed(false)
+                 IdSet<MaxExpression<Domain> >(system.maxExpressionCount()))
   {}
 
   void setRho(DynamicVariableAssignment<Domain>& rho) {
     _rho = &rho;
   }
 
-  void hasChanged(bool c) {
-    _changed = c;
-  }
-
-  bool hasChanged() const {
-    return _changed;
-  }
-
   unsigned int get(const MaxExpression<Domain>& e) const {
     log::strategy << indent() << "Look up " << e << std::endl;
     return _values[e];
@@ -99,32 +90,32 @@ struct DynamicMaxStrategy : public MaxStrategy<Domain> {
 private:
   void solve(const MaxExpression<Domain>& x) {
     if (!_stable.contains(x)) {
+      std::cerr << indent() << x.id() << std::endl; 
       _stable.insert(x);
       log::strategy << indent() << "Stabilise " << x << std::endl;
 
       stack_depth++; 
       DependencyAssignment assignment(*this, *_rho, x);
       DependencyStrategy depStrat(*this, x);
-      unsigned int val = x.bestStrategy(assignment, depStrat);
+      unsigned int val = x.bestStrategy(assignment, depStrat, _values[x]);
       stack_depth--;
 
       if (val != _values[x]) {
+        std::cerr << indent() << "-" << std::endl;
         log::strategy << x << " => " << *x.arguments()[val] << std::endl;
 
-        IdSet<MaxExpression<Domain> > oldInfluence = _influence[x];
-        //_influence[x].clear();
         _values[x] = val;
-        _changed = true;
 
         _rho->invalidate(*_system.varFromExpr(x));
         
 	//_rho->stabilise();
 
-        _stable.filter(oldInfluence);
-
+        IdSet<MaxExpression<Domain> > infl = _influence[x];
+        _stable.filter(infl); 
+        
         for (typename IdSet<MaxExpression<Domain> >::iterator
-               it = oldInfluence.begin(),
-               end = oldInfluence.end();
+               it = infl.begin(),
+               end = infl.end();
              it != end;
              ++it) {
           solve(_system.maxExpression(*it));
@@ -150,6 +141,7 @@ private:
     }
     const Domain operator[](const Variable<Domain>& var) {
       // solve the strategy for this variable, too
+      // recursive magic!
       _strat.solve(*_strat._system[var]);
       _strat._influence[*_strat._system[var]].insert(_expr);
       return _rho[var];
@@ -186,7 +178,6 @@ private:
   IdMap<MaxExpression<Domain>,unsigned int> _values;
   IdSet<MaxExpression<Domain> > _stable;
   IdMap<MaxExpression<Domain>,IdSet<MaxExpression<Domain> > > _influence;
-  bool _changed;
 };
 
 
@@ -200,28 +191,12 @@ struct Solver {
   }
 
   Domain solve(Variable<Domain>& var) {
-    MaxExpression<Domain>& rhs = *_system[var];
-
-    // _rho automatically keeps up to date with changes made to the
-    // strategy, so you don't need to stabilise it
-
+      MaxExpression<Domain>& rhs = *_system[var];
+    // this will automatically work sufficiently to get the final
+    // strategy for this variable's RHS
     _strategy.get(rhs);
 
-
-    /*
-    do {
-      _strategy.hasChanged(false);
-      
-      log::debug << "Stabilise assignment (toplevel)" << std::endl;
-      _rho.stabilise();
-      
-      log::debug << "Improve strategy (toplevel)" << std::endl;
-      // improve strategy
-      _strategy.get(rhs);
-      log::debug << (_strategy.hasChanged() ? "Strategy has changed - loop again" : "Strategy has not changed - terminate") << std::endl;
-    } while (_strategy.hasChanged());
-    */
-
+    // this will automatically solve for the value of the RHS, if required
     return _rho[var];
   }
 private:
-- 
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