001/* Copyright (C) 2013 TU Dortmund
002 * This file is part of AutomataLib, http://www.automatalib.net/.
003 * 
004 * AutomataLib is free software; you can redistribute it and/or
005 * modify it under the terms of the GNU Lesser General Public
006 * License version 3.0 as published by the Free Software Foundation.
007 * 
008 * AutomataLib is distributed in the hope that it will be useful,
009 * but WITHOUT ANY WARRANTY; without even the implied warranty of
010 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
011 * Lesser General Public License for more details.
012 * 
013 * You should have received a copy of the GNU Lesser General Public
014 * License along with AutomataLib; if not, see
015 * http://www.gnu.de/documents/lgpl.en.html.
016 */
017package net.automatalib.brics;
018
019import java.util.Collection;
020import java.util.Set;
021
022import net.automatalib.automata.abstractimpl.AbstractDeterministicAutomaton;
023import net.automatalib.automata.fsa.DFA;
024import net.automatalib.automata.fsa.abstractimpl.AbstractDFA;
025import dk.brics.automaton.Automaton;
026import dk.brics.automaton.State;
027
028/**
029 * Adapter class for wrapping a Brics automaton as a {@link DFA}.
030 * <p>
031 * This adapter is backed by the Brics automaton, so changes to the {@link Automaton}
032 * are reflected. Please note that any changes which result in a loss of determinism
033 * will result in incorrect behavior exposed by this class until determinism is restored.
034 *  
035 * @author Malte Isberner <malte.isberner@gmail.com>
036 *
037 */
038public class BricsDFA extends AbstractBricsAutomaton implements
039                DFA<State, Character> {
040        
041        private static Automaton requireDeterministic(Automaton aut, boolean mayDeterminize) {
042                if(aut.isDeterministic()) {
043                        if(!mayDeterminize)
044                                throw new IllegalArgumentException("A BricsDFA expects a deterministic automaton");
045                        aut.determinize();
046                }
047                return aut;
048        }
049
050        /**
051         * Constructor. If the specified automaton is not deterministic, this will result
052         * in an {@link IllegalArgumentException}.
053         * @param automaton the Brics automaton to wrap.
054         */
055        public BricsDFA(Automaton automaton) {
056                this(automaton, false);
057        }
058        
059        /**
060         * Constructor. If <tt>mayDeterminize</tt> is false, this constructor behaves as the above
061         * {@link #BricsDFA(Automaton)}. Otherwise, if the specified automaton is not deterministic,
062         * it is determinized beforehand by invoking {@link Automaton#determinize()}.
063         * @param automaton the Brics automaton to wrap.
064         * @param mayDeterminize whether or not a possible nondeterministic automaton may be
065         * determinized.
066         */
067        public BricsDFA(Automaton automaton, boolean mayDeterminize) {
068                super(requireDeterministic(automaton, mayDeterminize));
069        }
070
071        /*
072         * (non-Javadoc)
073         * @see net.automatalib.ts.acceptors.AcceptorTS#accepts(java.lang.Iterable)
074         */
075        @Override
076        public boolean accepts(Iterable<Character> input) {
077                return AbstractDFA.accepts(this, input);
078        }
079
080        /*
081         * (non-Javadoc)
082         * @see net.automatalib.ts.simple.SimpleDTS#getInitialState()
083         */
084        @Override
085        public State getInitialState() {
086                return automaton.getInitialState();
087        }
088
089        /*
090         * (non-Javadoc)
091         * @see net.automatalib.ts.simple.SimpleDTS#getSuccessor(java.lang.Object, java.lang.Object)
092         */
093        @Override
094        public State getSuccessor(State state, Character input) {
095                return state.step(input.charValue());
096        }
097
098        /*
099         * (non-Javadoc)
100         * @see net.automatalib.ts.simple.SimpleDTS#getSuccessor(java.lang.Object, java.lang.Iterable)
101         */
102        @Override
103        public State getSuccessor(State state, Iterable<Character> input) {
104                return AbstractDeterministicAutomaton.getSuccessor(this, state, input);
105        }
106
107        /*
108         * (non-Javadoc)
109         * @see net.automatalib.ts.simple.SimpleDTS#getState(java.lang.Iterable)
110         */
111        @Override
112        public State getState(Iterable<Character> input) {
113                return AbstractDeterministicAutomaton.getState(this, input);
114        }
115
116        /*
117         * (non-Javadoc)
118         * @see net.automatalib.ts.DeterministicTransitionSystem#getTransition(java.lang.Object, java.lang.Object)
119         */
120        @Override
121        public State getTransition(State state, Character input) {
122                return state.step(input.charValue());
123        }
124
125        /*
126         * (non-Javadoc)
127         * @see net.automatalib.brics.AbstractBricsAutomaton#getTransitions(dk.brics.automaton.State, java.lang.Character)
128         */
129        @Override
130        public Collection<State> getTransitions(State state, Character input) {
131                return AbstractDeterministicAutomaton.getTransitions(this, state, input);
132        }
133
134        /*
135         * (non-Javadoc)
136         * @see net.automatalib.ts.abstractimpl.AbstractTS#getSuccessors(java.lang.Object, java.lang.Object)
137         */
138        @Override
139        public Set<State> getSuccessors(State state, Character input) {
140                return AbstractDeterministicAutomaton.getSuccessors(this, state, input);
141        }
142        
143        
144}