internal static Automaton Concatenate(Automaton a1, Automaton a2)
{
if (a1.IsSingleton && a2.IsSingleton)
{
return(BasicAutomata.MakeString(a1.Singleton + a2.Singleton));
}
if (BasicOperations.IsEmpty(a1) || BasicOperations.IsEmpty(a2))
{
return(BasicAutomata.MakeEmpty());
}
bool deterministic = a1.IsSingleton && a2.IsDeterministic;
if (a1 == a2)
{
a1 = a1.CloneExpanded();
a2 = a2.CloneExpanded();
}
else
{
a1 = a1.CloneExpandedIfRequired();
a2 = a2.CloneExpandedIfRequired();
}
foreach (State s in a1.GetAcceptStates())
{
s.Accept = false;
s.AddEpsilon(a2.Initial);
}
a1.IsDeterministic = deterministic;
a1.ClearHashCode();
a1.CheckMinimizeAlways();
return(a1);
}
private Automaton ToAutomaton(
IDictionary <string, Automaton> automata,
IAutomatonProvider automatonProvider,
bool minimize)
{
IList <Automaton> list;
Automaton a = null;
switch (this.kind)
{
case Kind.RegexpUnion:
list = new List <Automaton>();
this.FindLeaves(this.exp1, Kind.RegexpUnion, list, automata, automatonProvider, minimize);
this.FindLeaves(this.exp2, Kind.RegexpUnion, list, automata, automatonProvider, minimize);
a = BasicOperations.Union(list);
a.Minimize();
break;
case Kind.RegexpConcatenation:
list = new List <Automaton>();
this.FindLeaves(this.exp1, Kind.RegexpConcatenation, list, automata, automatonProvider, minimize);
this.FindLeaves(this.exp2, Kind.RegexpConcatenation, list, automata, automatonProvider, minimize);
a = BasicOperations.Concatenate(list);
a.Minimize();
break;
case Kind.RegexpIntersection:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize)
.Intersection(this.exp2.ToAutomaton(automata, automatonProvider, minimize));
a.Minimize();
break;
case Kind.RegexpOptional:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Optional();
a.Minimize();
break;
case Kind.RegexpRepeat:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat();
a.Minimize();
break;
case Kind.RegexpRepeatMin:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat(this.min);
a.Minimize();
break;
case Kind.RegexpRepeatMinMax:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Repeat(this.min, this.max);
a.Minimize();
break;
case Kind.RegexpComplement:
a = this.exp1.ToAutomaton(automata, automatonProvider, minimize).Complement();
a.Minimize();
break;
case Kind.RegexpChar:
a = BasicAutomata.MakeChar(this.c);
break;
case Kind.RegexpCharRange:
a = BasicAutomata.MakeCharRange(this.@from, this.to);
break;
case Kind.RegexpAnyChar:
a = BasicAutomata.MakeAnyChar();
break;
case Kind.RegexpEmpty:
a = BasicAutomata.MakeEmpty();
break;
case Kind.RegexpString:
a = BasicAutomata.MakeString(this.s);
break;
case Kind.RegexpAnyString:
a = BasicAutomata.MakeAnyString();
break;
case Kind.RegexpAutomaton:
Automaton aa = null;
if (automata != null)
{
automata.TryGetValue(this.s, out aa);
}
if (aa == null && automatonProvider != null)
{
try
{
aa = automatonProvider.GetAutomaton(this.s);
}
catch (IOException e)
{
throw new ArgumentException(string.Empty, e);
}
}
if (aa == null)
{
throw new ArgumentException("'" + this.s + "' not found");
}
a = aa.Clone(); // Always clone here (ignore allowMutate).
break;
case Kind.RegexpInterval:
a = BasicAutomata.MakeInterval(this.min, this.max, this.digits);
break;
}
return(a);
}
internal static Automaton MakeString(string s)
{
return(BasicAutomata.MakeString(s));
}
internal static Automaton Concatenate(IList <Automaton> l)
{
if (l.Count == 0)
{
return(BasicAutomata.MakeEmptyString());
}
bool allSingleton = l.All(a => a.IsSingleton);
if (allSingleton)
{
var b = new StringBuilder();
foreach (Automaton a in l)
{
b.Append(a.Singleton);
}
return(BasicAutomata.MakeString(b.ToString()));
}
else
{
if (l.Any(a => a.IsEmpty))
{
return(BasicAutomata.MakeEmpty());
}
var ids = new HashSet <int>();
foreach (Automaton a in l)
{
ids.Add(RuntimeHelpers.GetHashCode(a));
}
bool hasAliases = ids.Count != l.Count;
Automaton b = l[0];
b = hasAliases ? b.CloneExpanded() : b.CloneExpandedIfRequired();
var ac = b.GetAcceptStates();
bool first = true;
foreach (Automaton a in l)
{
if (first)
{
first = false;
}
else
{
if (a.IsEmptyString())
{
continue;
}
Automaton aa = a;
aa = hasAliases ? aa.CloneExpanded() : aa.CloneExpandedIfRequired();
HashSet <State> ns = aa.GetAcceptStates();
foreach (State s in ac)
{
s.Accept = false;
s.AddEpsilon(aa.Initial);
if (s.Accept)
{
ns.Add(s);
}
}
ac = ns;
}
}
b.IsDeterministic = false;
b.ClearHashCode();
b.CheckMinimizeAlways();
return(b);
}
}