package codelines;

import animation.CodeLine;
import animation.ControlFlow;
import animation.Memory;

public class DeclareVariable <T> extends CodeLine {

	private boolean oldExists;
	private T val;
	private String name;
	
	public DeclareVariable( String name, T value )
	{
		this.val = value;
		this.name = name;
	}

	@Override
	public ControlFlow runForward(Memory m) {
		
		oldExists = m.isDefined( name, false );
		T oldVal = m.read( name, false );
		m.declare( name, val, false );
		actions.add( (Memory mem) -> {
			if( !oldExists )
				m.undeclare( name, false );
			else
				m.declare( name, oldVal, false );
			return new ControlFlow( ControlFlow.STEP_OVER );
		});
		return new ControlFlow( ControlFlow.STEP_OVER );
	}
}