ChunkEditUnit.java

package ruc.irm.similarity.sentence.editdistance;


public class ChunkEditUnit extends EditUnit {
	private SuperString<? extends EditUnit> chunk = null;
	
	public ChunkEditUnit(SuperString<? extends EditUnit> chunk){
		this.chunk = chunk;
	}
		
	public String getUnitString() {
		return chunk.toString();
	}
	
	/**
	 * 根据此语的相似度获取替换代价
	 */
	@Override
	public double getSubstitutionCost(EditUnit otherUnit){
		if(!(otherUnit instanceof ChunkEditUnit)) return chunk.length();
		if(equals(otherUnit)) return 0.0;
		
		ChunkEditUnit other = (ChunkEditUnit)otherUnit;
		return new StandardEditDistance().getEditDistance(chunk, other.chunk);
	}
	
	/**
     * 获取删除代价,标准算法的默认值为1.0, 此处也设为1.0
     * 具体的编辑单元可以通过覆盖该方法设置不同的删除代价
     * @return 删除代价
     */
    public double getDeletionCost(){
        return chunk.length();
    }    
    
    /**
     * 获取插入代价,标准算法的默认值为1.0.
     * 具体的编辑单元可以通过覆盖该方法设置不同的插入代价
     */
    public double getInsertionCost(){
        return chunk.length();
    }
	
}