/**
* 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 org.apache.ctakes.drugner.fsm.machines.elements;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.ctakes.core.fsm.condition.IntegerValueCondition;
import org.apache.ctakes.core.fsm.condition.NumberCondition;
import org.apache.ctakes.core.fsm.condition.PunctuationValueCondition;
import org.apache.ctakes.core.fsm.state.NamedState;
import org.apache.ctakes.core.fsm.token.BaseToken;
import org.apache.ctakes.drugner.fsm.output.util.DecimalStrengthToken;
import net.openai.util.fsm.AnyCondition;
import net.openai.util.fsm.Machine;
import net.openai.util.fsm.State;
/**
* Uses one or more finite state machines to detect decimal fractions in the given
* input of tokens.
* @author Mayo Clinic
*/
public class DecimalStrengthFSM
{
// contains the finite state machines
private Set iv_machineSet = new HashSet();
/**
*
* Constructor
*
*/
public DecimalStrengthFSM()
{
iv_machineSet.add(getDecimalStrengthMachine());
}
/**
* Gets a finite state machine that detects the following:
* <ol>
* <li>0.5*</li>
* </ol>
* @return
*/
private Machine getDecimalStrengthMachine()
{
State startState = new NamedState("START");
State endState = new NamedState("END");
endState.setEndStateFlag(true);
Machine m = new Machine(startState);
State zeroNumState = new NamedState("ZERO_NUM");
State fractionTextState = new NamedState("NUMERATOR_TEXT");
State dashState = new NamedState("DASH");
startState.addTransition(new IntegerValueCondition(0), zeroNumState);
startState.addTransition(new AnyCondition(), startState);
zeroNumState.addTransition(new PunctuationValueCondition('.'), fractionTextState);
zeroNumState.addTransition(new AnyCondition(), startState);
fractionTextState.addTransition(new NumberCondition(), dashState);
fractionTextState.addTransition(new AnyCondition(), startState);
dashState.addTransition(new PunctuationValueCondition('-'), endState);
dashState.addTransition(new AnyCondition(), startState);
endState.addTransition(new AnyCondition(), startState);
return m;
}
/**
* Executes the finite state machines.
* @param tokens
* @return Set of FractionToken objects.
* @throws Exception
*/
public Set execute(List tokens) throws Exception
{
Set fractionSet = new HashSet();
// maps a fsm to a token start index
// key = fsm , value = token start index
Map tokenStartMap = new HashMap();
for (int i = 0; i < tokens.size(); i++)
{
BaseToken token = (BaseToken) tokens.get(i);
Iterator machineItr = iv_machineSet.iterator();
while (machineItr.hasNext())
{
Machine fsm = (Machine) machineItr.next();
fsm.input(token);
State currentState = fsm.getCurrentState();
if (currentState.getStartStateFlag())
{
tokenStartMap.put(fsm, Integer.valueOf(i));
}
if (currentState.getEndStateFlag())
{
Object o = tokenStartMap.get(fsm);
int tokenStartIndex;
if (o == null)
{
// By default, all machines start with
// token zero.
tokenStartIndex = 0;
}
else
{
tokenStartIndex = ((Integer) o).intValue();
// skip ahead over single token we don't want
tokenStartIndex++;
}
BaseToken startToken =
(BaseToken) tokens.get(tokenStartIndex);
BaseToken endToken = token;
DecimalStrengthToken fractionToken =
new DecimalStrengthToken(
startToken.getStartOffset(),
endToken.getEndOffset());
fractionSet.add(fractionToken);
fsm.reset();
}
}
}
// cleanup
tokenStartMap.clear();
// reset machines
Iterator itr = iv_machineSet.iterator();
while (itr.hasNext())
{
Machine fsm = (Machine) itr.next();
fsm.reset();
}
return fractionSet;
}
}