ocarina/include/core/filter.h

/**
 * Copyright 2013 (c) Anna Schumaker.
 */
#ifndef OCARINA_CORE_FILTER_H
#define OCARINA_CORE_FILTER_H

extern "C" {
#include <core/set.h>
}

#include <string>

/**
 * The filter layer is used to find a subset of songs based on an input
 * string.  Since this layer does text processing, it also provides a
 * functions for converting strings to lowercase.
 *
 * The text processing is mostly interested in alphanumeric characters, so
 * any special characters included in the input text will be stripped out.
 * Tabs, spaces and the following characters are used to delimit words:
 *
 * 	\/,;()_-~+"
 */
namespace filter {

	/**
	 * Break the input text into lowercase words and search the Index
	 * for matches.  The results set should be filled out with the
	 * intersection of the IndexEntry for each word.  If any word does
	 * not appear in the index, then the result set should be empty.
	 *
	 * @param  text  The text to search for.
	 * @param  res   The results set to fill in with matching indexes.
	 */
	void search(const std::string &, struct set *);

	/**
	 * Converts the input text to lowercase and returns the result.
	 *
	 * @param  text  The text to be converted.
	 * @return The lowercase form of the input text.
	 */
	std::string lowercase(const std::string &);

};

void filter_init();
void filter_deinit();

/* Add the input string to the index. */
void filter_add(const gchar *, unsigned int);

#endif /* OCARINA_CORE_FILTER_H */