fr.univnantes.lina.uima.tkregex.AutomatonBuilder.java Source code

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Here is the source code for fr.univnantes.lina.uima.tkregex.AutomatonBuilder.java

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/*******************************************************************************
 * Copyright 2015 - CNRS (Centre National de Recherche Scientifique)
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 *
 *******************************************************************************/
package fr.univnantes.lina.uima.tkregex;

import java.util.List;
import java.util.Set;
import java.util.TreeSet;

import com.google.common.collect.Lists;

public class AutomatonBuilder {

    private State initState;
    private Set<State> states;
    private Set<State> acceptingStates;

    private List<AnnotationMatcher> matcherList;
    private List<AutomatonQuantifier> quantifierList;

    public AutomatonBuilder() {
        super();
        this.matcherList = Lists.newLinkedList();
        this.quantifierList = Lists.newLinkedList();
        this.initState = null;
        this.states = new TreeSet<State>();
        this.acceptingStates = new TreeSet<State>();
    }

    //   public void initAutomaton() {
    //   }

    public State addState() {
        State state = new State();
        this.states.add(state);
        return state;
    }

    public State addAcceptingState() {
        State state = this.addState();
        this.acceptingStates.add(state);
        return state;
    }

    public State addInitState() {
        State s = this.addState();
        this.initState = s;
        return s;
    }

    public Transition addTransition(State from, AnnotationMatcher m, State to) {
        Transition transition = new Transition();
        transition.setFromState(from);
        transition.setToState(to);
        transition.setMatcher(m);
        from.addTransition(transition);
        return transition;
    }

    public Transition addEpsilonTransition(State from, State to) {
        EpsilonTransition transition = new EpsilonTransition();
        transition.setFromState(from);
        transition.setToState(to);
        from.addTransition(transition);
        return transition;
    }

    public Automaton getAutomaton() {
        if (!this.quantifierList.isEmpty()) {
            if (this.initState != null)
                throw new IllegalStateException(
                        "Init state should not be used in builder's matcher/quatifier mode");
            State lastState = this.addInitState();
            for (int i = 0; i < this.matcherList.size(); i++) {
                AnnotationMatcher matcher = this.matcherList.get(i);
                AutomatonQuantifier quantifier = this.quantifierList.get(i);
                if (quantifier.getQuantifierType().equals(AutomatonQuantifier.ONE)) {
                    acceptingStates.remove(lastState);
                    State state = addState();
                    addTransition(lastState, matcher, state);
                    lastState = state;
                    acceptingStates.add(lastState);
                } else if (quantifier.getQuantifierType().equals(AutomatonQuantifier.N)) {
                    acceptingStates.remove(lastState);
                    for (int k = 0; k < quantifier.getLowerBound(); k++) {
                        State state = addState();
                        addTransition(lastState, matcher, state);
                        lastState = state;
                    }
                } else if (quantifier.getQuantifierType().equals(AutomatonQuantifier.ZERO_ONE)) {
                    acceptingStates.remove(lastState);
                    State state = addState();
                    addTransition(lastState, matcher, state);
                    addEpsilonTransition(lastState, state);
                    lastState = state;
                    acceptingStates.add(lastState);
                } else if (quantifier.getQuantifierType().equals(AutomatonQuantifier.ZERO_N)) {
                    acceptingStates.remove(lastState);
                    State state = addState();
                    addEpsilonTransition(lastState, state);
                    addTransition(state, matcher, state);
                    lastState = state;
                    acceptingStates.add(lastState);
                } else if (quantifier.getQuantifierType().equals(AutomatonQuantifier.ONE_N)) {
                    acceptingStates.remove(lastState);
                    State state = addState();
                    addTransition(lastState, matcher, state);
                    addTransition(state, matcher, state);
                    lastState = state;
                    acceptingStates.add(lastState);
                } else
                    throw new UnsupportedOperationException(
                            "No yet recognized regex: " + quantifier.getQuantifierType());
            }
            Automaton automaton = new Automaton(initState, acceptingStates, states);
            return automaton;
        } else {
            if (this.initState == null)
                throw new IllegalStateException("No initial state defined.");
            Automaton automaton = new Automaton(initState, acceptingStates, states);
            return automaton;
        }
    }

    //   public void addMatcher(AnnotationMatcher lastExpression,
    //         AutomatonQuantifier quantifier) {
    //      this.matcherList.add(lastExpression);
    //      this.quantifierList.add(quantifier);
    //   }

}