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/* Copyright (C) 2013 TU Dortmund
* This file is part of LearnLib, http://www.learnlib.de/.
*
* LearnLib is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License version 3.0 as published by the Free Software Foundation.
*
* LearnLib is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with LearnLib; if not, see
* .
*/
package de.learnlib.algorithms.lstargeneric.table;
import net.automatalib.words.Word;
/**
* A row in an observation table. Minimally, a row consists of a prefix (the row label)
* and a unique identifier in its observation table which remains constant throughout the
* whole process.
*
* Apart from that, a row is also associated with contents (via an integer id). The prefix of a row
* may be either a short or long prefix. In the former case, the row will also have successor rows
* (one-step futures) associated with it.
*
* @author Malte Isberner
*
* @param input symbol class
*/
public final class Row {
private final Word prefix;
private final int rowId;
private int rowContentId = -1;
private int lpIndex = 0;
private Row[] successors = null;
/**
* Constructor.
* @param prefix the prefix (label) of this row
* @param rowId the unique row identifier
*/
public Row(Word prefix, int rowId) {
this.prefix = prefix;
this.rowId = rowId;
}
/**
* Constructor for short prefix rows.
* @param prefix the prefix (label) of this row
* @param rowId the unique row identifier
* @param alphabetSize the size of the alphabet, used for initializing the successor array
*/
public Row(Word prefix, int rowId, int alphabetSize) {
this(prefix, rowId);
makeShort(alphabetSize);
}
/**
* Makes this row a short prefix row. This leads to a successor array being created.
* If this row already is a short prefix row, nothing happens.
* @param alphabetSize the size of the input alphabet.
*/
@SuppressWarnings("unchecked")
public void makeShort(int alphabetSize) {
if(lpIndex == -1)
return;
lpIndex = -1;
this.successors = (Row[])new Row[alphabetSize];
}
/**
* Retrieves the successor row for this short prefix row and the given alphabet
* symbol (by index). If this is no short prefix row, an exception might occur.
* @param inputIdx the index of the alphabet symbol.
* @return the successor row (may be null)
*/
public Row getSuccessor(int inputIdx) {
return successors[inputIdx];
}
/**
* Sets the successor row for this short prefix row and the given alphabet symbol
* (by index). If this is no short prefix row, an exception might occur.
* @param inputIdx the index of the alphabet symbol.
* @param succ the successor row
*/
public void setSuccessor(int inputIdx, Row succ) {
successors[inputIdx] = succ;
}
/**
* Retrieves the prefix (row label) associated with this row.
* @return the prefix
*/
public Word getPrefix() {
return prefix;
}
/**
* Retrieves the unique row identifier associated with this row.
* @return the row identifier
*/
public int getRowId() {
return rowId;
}
/**
* Retrieves the ID of the row contents (may be -1 if this row has not
* yet been initialized).
* @return the contents id.
*/
public int getRowContentId() {
return rowContentId;
}
/**
* Sets the ID of the row contents.
* @param id the contents id
*/
public void setRowContentId(int id) {
this.rowContentId = id;
}
/**
* Retrieves whether this is a short prefix row.
* @return true if this is a short prefix row, false otherwise.
*/
public boolean isShortPrefix() {
return (lpIndex == -1);
}
public boolean hasContents() {
return (rowContentId != -1);
}
int getLpIndex() {
return lpIndex;
}
void setLpIndex(int lpIndex) {
this.lpIndex = lpIndex;
}
}