package dk.itu.oop.lecture5;

public class CompactNonLetters implements OOPIterator {
	private OOPIterator in;
	private boolean packed;
	// if packed, then head is ".", else head is in.head

	public CompactNonLetters(OOPIterator in){
		this.in = in;
		packNonLetters();
	}

	private void packNonLetters(){
		if ( in.hasNext() )
			if ( !isLetter()){
				packed = true;
				while (in.hasNext() && !isLetter() )
					in.next();
			} else
				packed = false;
		else
			packed = true;
	}

	public boolean hasNext(){ return in.hasNext() || packed; }

	public Object peek(){
		return (packed? new Character('.') : in.peek() );
	}

	public Object next(){
		Object o = peek();
		if (packed)
			packed = false;
		else{
			in.next();
			packNonLetters();
		}
		return o;
	}

	private boolean isLetter(){
		return Character.isLetter( ( (Character) in.peek() ).charValue() );
	}

	public OOPIterator cloneMe(){
		try{
			CompactNonLetters clone = (CompactNonLetters)super.clone();
			clone.in = in.cloneMe();
			return clone;
		}catch(CloneNotSupportedException e){
			return null;
		}
	}

	public static void main(String[] args){
		String haddock = "You #!@ Miserable earthworms! Numbskulls! and Carpet-sellers";
		OOPIterator itr = new CompactNonLetters(new CharacterIterator( haddock ) );
		while (itr.hasNext())
			System.out.print( itr.next() );
		System.out.println();
	}

}