code: public Value check(ILexNameToken name)
  	{
  		Value v = get(name);
  
  		if (v == null)
  		{
  			if (outer != null)
  			{
  				return outer.check(name);
  			}
  		}
  
  		return v;
  	}
docs: Get the value for a given name. This searches outer contexts, if any are present.
  
  @param name
  The name to look for.
  @return The value of the name, or null.