Beispiel #1
0
        public CompiledAutomaton(Automaton automaton, bool?finite, bool simplify)
        {
            if (simplify)
            {
                // Test whether the automaton is a "simple" form and
                // if so, don't create a runAutomaton.  Note that on a
                // large automaton these tests could be costly:
                if (BasicOperations.IsEmpty(automaton))
                {
                    // matches nothing
                    Type              = AUTOMATON_TYPE.NONE;
                    Term              = null;
                    CommonSuffixRef   = null;
                    RunAutomaton      = null;
                    sortedTransitions = null;
                    this.Finite       = null;
                    return;
                }
                else if (BasicOperations.IsTotal(automaton))
                {
                    // matches all possible strings
                    Type              = AUTOMATON_TYPE.ALL;
                    Term              = null;
                    CommonSuffixRef   = null;
                    RunAutomaton      = null;
                    sortedTransitions = null;
                    this.Finite       = null;
                    return;
                }
                else
                {
                    string commonPrefix;
                    string singleton;
                    if (automaton.Singleton == null)
                    {
                        commonPrefix = SpecialOperations.GetCommonPrefix(automaton);
                        if (commonPrefix.Length > 0 && BasicOperations.SameLanguage(automaton, BasicAutomata.MakeString(commonPrefix)))
                        {
                            singleton = commonPrefix;
                        }
                        else
                        {
                            singleton = null;
                        }
                    }
                    else
                    {
                        commonPrefix = null;
                        singleton    = automaton.Singleton;
                    }

                    if (singleton != null)
                    {
                        // matches a fixed string in singleton or expanded
                        // representation
                        Type              = AUTOMATON_TYPE.SINGLE;
                        Term              = new BytesRef(singleton);
                        CommonSuffixRef   = null;
                        RunAutomaton      = null;
                        sortedTransitions = null;
                        this.Finite       = null;
                        return;
                    }
                    else if (BasicOperations.SameLanguage(automaton, BasicOperations.Concatenate(BasicAutomata.MakeString(commonPrefix), BasicAutomata.MakeAnyString())))
                    {
                        // matches a constant prefix
                        Type              = AUTOMATON_TYPE.PREFIX;
                        Term              = new BytesRef(commonPrefix);
                        CommonSuffixRef   = null;
                        RunAutomaton      = null;
                        sortedTransitions = null;
                        this.Finite       = null;
                        return;
                    }
                }
            }

            Type = AUTOMATON_TYPE.NORMAL;
            Term = null;
            if (finite == null)
            {
                this.Finite = SpecialOperations.IsFinite(automaton);
            }
            else
            {
                this.Finite = finite;
            }
            Automaton utf8 = (new UTF32ToUTF8()).Convert(automaton);

            if (this.Finite == true)
            {
                CommonSuffixRef = null;
            }
            else
            {
                CommonSuffixRef = SpecialOperations.GetCommonSuffixBytesRef(utf8);
            }
            RunAutomaton      = new ByteRunAutomaton(utf8, true);
            sortedTransitions = utf8.GetSortedTransitions();
        }
Beispiel #2
0
        /// <summary>
        /// Returns an automaton that accepts the intersection of the languages of the
        /// given automata. Never modifies the input automata languages.
        /// <para/>
        /// Complexity: quadratic in number of states.
        /// </summary>
        public static Automaton Intersection(Automaton a1, Automaton a2)
        {
            if (a1.IsSingleton)
            {
                if (BasicOperations.Run(a2, a1.singleton))
                {
                    return(a1.CloneIfRequired());
                }
                else
                {
                    return(BasicAutomata.MakeEmpty());
                }
            }
            if (a2.IsSingleton)
            {
                if (BasicOperations.Run(a1, a2.singleton))
                {
                    return(a2.CloneIfRequired());
                }
                else
                {
                    return(BasicAutomata.MakeEmpty());
                }
            }
            if (a1 == a2)
            {
                return(a1.CloneIfRequired());
            }
            Transition[][]                    transitions1 = a1.GetSortedTransitions();
            Transition[][]                    transitions2 = a2.GetSortedTransitions();
            Automaton                         c            = new Automaton();
            LinkedList <StatePair>            worklist     = new LinkedList <StatePair>();
            Dictionary <StatePair, StatePair> newstates    = new Dictionary <StatePair, StatePair>();
            StatePair                         p            = new StatePair(c.initial, a1.initial, a2.initial);

            worklist.AddLast(p);
            newstates[p] = p;
            while (worklist.Count > 0)
            {
                p = worklist.First.Value;
                worklist.Remove(p);
                p.s.accept = p.S1.accept && p.S2.accept;
                Transition[] t1 = transitions1[p.S1.number];
                Transition[] t2 = transitions2[p.S2.number];
                for (int n1 = 0, b2 = 0; n1 < t1.Length; n1++)
                {
                    while (b2 < t2.Length && t2[b2].max < t1[n1].min)
                    {
                        b2++;
                    }
                    for (int n2 = b2; n2 < t2.Length && t1[n1].max >= t2[n2].min; n2++)
                    {
                        if (t2[n2].max >= t1[n1].min)
                        {
                            StatePair q = new StatePair(t1[n1].to, t2[n2].to);
                            StatePair r;
                            newstates.TryGetValue(q, out r);
                            if (r == null)
                            {
                                q.s = new State();
                                worklist.AddLast(q);
                                newstates[q] = q;
                                r            = q;
                            }
                            int min = t1[n1].min > t2[n2].min ? t1[n1].min : t2[n2].min;
                            int max = t1[n1].max < t2[n2].max ? t1[n1].max : t2[n2].max;
                            p.s.AddTransition(new Transition(min, max, r.s));
                        }
                    }
                }
            }
            c.deterministic = a1.deterministic && a2.deterministic;
            c.RemoveDeadTransitions();
            c.CheckMinimizeAlways();
            return(c);
        }
Beispiel #3
0
        /// <summary>
        /// Returns true if the language of <paramref name="a1"/> is a subset of the language
        /// of <paramref name="a2"/>. As a side-effect, <paramref name="a2"/> is determinized if
        /// not already marked as deterministic.
        /// <para/>
        /// Complexity: quadratic in number of states.
        /// </summary>
        public static bool SubsetOf(Automaton a1, Automaton a2)
        {
            if (a1 == a2)
            {
                return(true);
            }
            if (a1.IsSingleton)
            {
                if (a2.IsSingleton)
                {
                    return(a1.singleton.Equals(a2.singleton, StringComparison.Ordinal));
                }
                return(BasicOperations.Run(a2, a1.singleton));
            }
            a2.Determinize();
            Transition[][]         transitions1 = a1.GetSortedTransitions();
            Transition[][]         transitions2 = a2.GetSortedTransitions();
            LinkedList <StatePair> worklist     = new LinkedList <StatePair>();
            HashSet <StatePair>    visited      = new HashSet <StatePair>();
            StatePair p = new StatePair(a1.initial, a2.initial);

            worklist.AddLast(p);
            visited.Add(p);
            while (worklist.Count > 0)
            {
                p = worklist.First.Value;
                worklist.Remove(p);
                if (p.S1.accept && !p.S2.accept)
                {
                    return(false);
                }
                Transition[] t1 = transitions1[p.S1.number];
                Transition[] t2 = transitions2[p.S2.number];
                for (int n1 = 0, b2 = 0; n1 < t1.Length; n1++)
                {
                    while (b2 < t2.Length && t2[b2].max < t1[n1].min)
                    {
                        b2++;
                    }
                    int min1 = t1[n1].min, max1 = t1[n1].max;

                    for (int n2 = b2; n2 < t2.Length && t1[n1].max >= t2[n2].min; n2++)
                    {
                        if (t2[n2].min > min1)
                        {
                            return(false);
                        }
                        if (t2[n2].max < Character.MAX_CODE_POINT)
                        {
                            min1 = t2[n2].max + 1;
                        }
                        else
                        {
                            min1 = Character.MAX_CODE_POINT;
                            max1 = Character.MIN_CODE_POINT;
                        }
                        StatePair q = new StatePair(t1[n1].to, t2[n2].to);
                        if (!visited.Contains(q))
                        {
                            worklist.AddLast(q);
                            visited.Add(q);
                        }
                    }
                    if (min1 <= max1)
                    {
                        return(false);
                    }
                }
            }
            return(true);
        }
Beispiel #4
0
        /// <summary>
        /// Returns true if the language of <paramref name="a1"/> is a subset of the language
        /// of <paramref name="a2"/>. As a side-effect, <paramref name="a2"/> is determinized if
        /// not already marked as deterministic.
        /// <para/>
        /// Complexity: quadratic in number of states.
        /// </summary>
        public static bool SubsetOf(Automaton a1, Automaton a2)
        {
            if (a1 == a2)
            {
                return(true);
            }
            if (a1.IsSingleton)
            {
                if (a2.IsSingleton)
                {
                    return(a1.singleton.Equals(a2.singleton, StringComparison.Ordinal));
                }
                return(BasicOperations.Run(a2, a1.singleton));
            }
            a2.Determinize();
            Transition[][]    transitions1 = a1.GetSortedTransitions();
            Transition[][]    transitions2 = a2.GetSortedTransitions();
            Queue <StatePair> worklist     = new Queue <StatePair>(); // LUCENENET specific - Queue is much more performant than LinkedList

            JCG.HashSet <StatePair> visited = new JCG.HashSet <StatePair>();
            StatePair p = new StatePair(a1.initial, a2.initial);

            worklist.Enqueue(p);
            visited.Add(p);
            while (worklist.Count > 0)
            {
                p = worklist.Dequeue();
                if (p.s1.accept && !p.s2.accept)
                {
                    return(false);
                }
                Transition[] t1 = transitions1[p.s1.number];
                Transition[] t2 = transitions2[p.s2.number];
                for (int n1 = 0, b2 = 0; n1 < t1.Length; n1++)
                {
                    while (b2 < t2.Length && t2[b2].max < t1[n1].min)
                    {
                        b2++;
                    }
                    int min1 = t1[n1].min, max1 = t1[n1].max;

                    for (int n2 = b2; n2 < t2.Length && t1[n1].max >= t2[n2].min; n2++)
                    {
                        if (t2[n2].min > min1)
                        {
                            return(false);
                        }
                        if (t2[n2].max < Character.MaxCodePoint)
                        {
                            min1 = t2[n2].max + 1;
                        }
                        else
                        {
                            min1 = Character.MaxCodePoint;
                            max1 = Character.MinCodePoint;
                        }
                        StatePair q = new StatePair(t1[n1].to, t2[n2].to);
                        if (!visited.Contains(q))
                        {
                            worklist.Enqueue(q);
                            visited.Add(q);
                        }
                    }
                    if (min1 <= max1)
                    {
                        return(false);
                    }
                }
            }
            return(true);
        }