///// <summary>
///// node is assumed to be in left-assoc form if it is a concatenation
///// </summary>
//Sequence<CounterOperation> GetNullabilityCondition_of_left_assoc(SymbolicRegexNode<S> node)
//{
// switch (node.kind)
// {
// case SymbolicRegexKind.StartAnchor:
// case SymbolicRegexKind.EndAnchor:
// case SymbolicRegexKind.Epsilon:
// {
// return Sequence<CounterOperation>.Empty;
// }
// case SymbolicRegexKind.Singleton:
// {
// return null;
// }
// case SymbolicRegexKind.Or:
// {
// if (node.isNullable)
// return Sequence<CounterOperation>.Empty;
// else
// return null;
// }
// case SymbolicRegexKind.Loop:
// {
// if (node.isNullable)
// return Sequence<CounterOperation>.Empty;
// else if (IsCountingLoop(node))
// return new Sequence<CounterOperation>(new CounterOperation(node, CounterOp.EXIT));
// else
// return null;
// }
// case SymbolicRegexKind.Concat:
// {
// var reset1 = GetNullabilityCondition_of_left_assoc(node.left);
// if (reset1 == null)
// return null;
// else
// {
// //we know that right is not a concat
// var reset2 = GetNullabilityCondition_of_left_assoc(node.right);
// if (reset2 == null)
// return null;
// else
// {
// //TBD: this optimization needs to be verified
// //if reset2 is nonempty it can only be a singleton
// if (reset1.IsEmpty || reset2.IsEmpty ||
// reset1.TrueForAll(x => reset2[0].Counter.ContainsSubCounter(x.Counter)))
// return reset1.Append(reset2);
// else if (reset2[0].Counter.LowerBound == 0)
// {
// return reset1;
// }
// else
// {
// return null;
// }
// }
// }
// }
// default:
// {
// throw new NotSupportedException("GetNullabilityCondition not supported for " + node.kind);
// }
// }
//}
internal SymbolicRegexNode <T> Transform <T>(SymbolicRegexNode <S> sr, SymbolicRegexBuilder <T> builderT, Func <S, T> predicateTransformer)
{
switch (sr.kind)
{
case SymbolicRegexKind.StartAnchor:
return(builderT.startAnchor);
case SymbolicRegexKind.EndAnchor:
return(builderT.endAnchor);
case SymbolicRegexKind.WatchDog:
return(builderT.MkWatchDog(sr.lower));
case SymbolicRegexKind.Epsilon:
return(builderT.epsilon);
case SymbolicRegexKind.Singleton:
return(builderT.MkSingleton(predicateTransformer(sr.set)));
//case SymbolicRegexKind.Sequence:
// return builderT.MkSequence(new Sequence<T>(Array.ConvertAll<S,T>(sr.sequence.ToArray(), x => predicateTransformer(x))));
case SymbolicRegexKind.Loop:
return(builderT.MkLoop(Transform(sr.left, builderT, predicateTransformer), sr.isLazyLoop, sr.lower, sr.upper));
case SymbolicRegexKind.Or:
return(builderT.MkOr(sr.alts.Transform(builderT, predicateTransformer)));
case SymbolicRegexKind.And:
return(builderT.MkAnd(sr.alts.Transform(builderT, predicateTransformer)));
case SymbolicRegexKind.Concat:
{
var sr_elems = sr.ToArray();
var sr_elems_trasformed = Array.ConvertAll(sr_elems, x => Transform(x, builderT, predicateTransformer));
return(builderT.MkConcat(sr_elems_trasformed, false));
}
default: //ITE
return
(builderT.MkIfThenElse(Transform(sr.IteCond, builderT, predicateTransformer),
Transform(sr.left, builderT, predicateTransformer),
Transform(sr.right, builderT, predicateTransformer)));
}
}
//public SymbolicRegexBuilder<S> SRBuilder
//{
// get
// {
// return srBuilder;
// }
//}
/// <summary>
/// Constructs a regex to symbolic finite automata converter
/// </summary>
/// <param name="solver">solver for character constraints</param>
/// <param name="categorizer">maps unicode categories to corresponding character conditions</param>
public RegexToAutomatonConverter(ICharAlgebra <S> solver, IUnicodeCategoryTheory <S> categorizer = null)
{
this.solver = solver;
this.categorizer = (categorizer == null ? new UnicodeCategoryTheory <S>(solver) : categorizer);
this.srBuilder = new SymbolicRegexBuilder <S>((ICharAlgebra <S>)solver);
}