package Practicals.Ex4;

import java.util.Set;
import Practicals.Ex3.WordStream;

public interface ConcordanceEx extends Concordance
{
	// Return a set of files mentioning (or not) the words specified by the expression.
	// The expression syntax would look like this - (Woof OR (Blah AND Moo) OR Baa) NOT Miaow -
	// were it not for the fact that it would make it harder to parse. Since this isn't an exercise in parsing,
	// I thought I'd make life a little simpler and write expressions in postfix form. The above therefore gets
	// translated to: Woof Blah Moo AND OR Baa OR Miaow NOT
	Set filesMentioning(String expression);		// returns Set<String>
}