NetDecisionBuilder.cs

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// Copyright 2010-2018 Google LLC
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
 
using System;
using System.Collections;
 
namespace Google.OrTools.ConstraintSolver
{
    public class NetDecisionBuilder : DecisionBuilder
    {
        public override Decision NextWrapper(Solver solver)
        {
            try
            {
                return Next(solver);
            }
            catch (ApplicationException /*e*/)
            {
                // TODO(user): Catch only fail exceptions.
                return solver.MakeFailDecision();
            }
        }
        public virtual Decision Next(Solver solver)
        {
            return null;
        }
    }
 
    public class NetDecision : Decision
    {
        public override void ApplyWrapper(Solver solver)
        {
            try
            {
                Apply(solver);
            }
            catch (ApplicationException /*e*/)
            {
                // TODO(user): Catch only fail exceptions.
                solver.ShouldFail();
            }
        }
        public virtual void Apply(Solver solver)
        {
            // By default, do nothing
        }
 
        public override void RefuteWrapper(Solver solver)
        {
            try
            {
                Refute(solver);
            }
            catch (ApplicationException /*e*/)
            {
                // TODO(user): Catch only fail exceptions.
                solver.ShouldFail();
            }
        }
        public virtual void Refute(Solver solver)
        {
        }
    }
 
    public class NetDemon : Demon
    {
        public override void RunWrapper(Solver solver)
        {
            try
            {
                Run(solver);
            }
            catch (ApplicationException /*e*/)
            {
                // TODO(user): Check that this is indeed a fail. Try implementing
                // custom exceptions (hard).
                solver.ShouldFail();
            }
        }
        public virtual void Run(Solver solver)
        {
        }
        public override int Priority()
        {
            return Solver.NORMAL_PRIORITY;
        }
        public override string ToString()
        {
            return "NetDemon";
        }
    }
 
    public class NetConstraint : Constraint
    {
        public NetConstraint(Solver s) : base(s)
        {
        }
 
        public override void InitialPropagateWrapper()
        {
            try
            {
                InitialPropagate();
            }
            catch (ApplicationException /*e*/)
            {
                solver().ShouldFail();
            }
        }
        public virtual void InitialPropagate()
        {
        }
        public override string ToString()
        {
            return "NetConstraint";
        }
    }
 
    public class IntVarEnumerator : IEnumerator
    {
        private IntVarIterator iterator_;
 
        // Enumerators are positioned before the first element
        // until the first MoveNext() call.
        private bool first_ = true;
 
        public IntVarEnumerator(IntVarIterator iterator)
        {
            iterator_ = iterator;
        }
 
        public bool MoveNext()
        {
            if (first_)
            {
                iterator_.Init();
                first_ = false;
            }
            else
            {
                iterator_.Next();
            }
            return iterator_.Ok();
        }
 
        public void Reset()
        {
            first_ = true;
        }
 
        object IEnumerator.Current
        {
            get {
                return Current;
            }
        }
 
        public long Current
        {
            get {
                if (!first_ && iterator_.Ok())
                {
                    return iterator_.Value();
                }
                else
                {
                    throw new InvalidOperationException();
                }
            }
        }
    }
 
    public partial class IntVarIterator : BaseObject, IEnumerable
    {
        IEnumerator IEnumerable.GetEnumerator()
        {
            return (IEnumerator)GetEnumerator();
        }
 
        public IntVarEnumerator GetEnumerator()
        {
            return new IntVarEnumerator(this);
        }
    }
} // namespace Google.OrTools.ConstraintSolver