OpenTTD-patches/src/string_base.h
2019-11-10 17:59:20 +00:00

65 lines
2.1 KiB
C++

/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef STRING_BASE_H
#define STRING_BASE_H
#include "string_type.h"
/** Class for iterating over different kind of parts of a string. */
class StringIterator {
public:
/** Type of the iterator. */
enum IterType {
ITER_CHARACTER, ///< Iterate over characters (or more exactly grapheme clusters).
ITER_WORD, ///< Iterate over words.
};
/** Sentinel to indicate end-of-iteration. */
static const size_t END = SIZE_MAX;
/**
* Create a new iterator instance.
* @return New iterator instance.
*/
static StringIterator *Create();
virtual ~StringIterator() {}
/**
* Set a new iteration string. Must also be called if the string contents
* changed. The cursor is reset to the start of the string.
* @param s New string.
*/
virtual void SetString(const char *s) = 0;
/**
* Change the current string cursor.
* @param pos New cursor position.
* @return Actual new cursor position at the next valid character boundary.
* @pre pos has to be inside the current string.
*/
virtual size_t SetCurPosition(size_t pos) = 0;
/**
* Advance the cursor by one iteration unit.
* @return New cursor position (in bytes) or #END if the cursor is already at the end of the string.
*/
virtual size_t Next(IterType what = ITER_CHARACTER) = 0;
/**
* Move the cursor back by one iteration unit.
* @return New cursor position (in bytes) or #END if the cursor is already at the start of the string.
*/
virtual size_t Prev(IterType what = ITER_CHARACTER) = 0;
protected:
StringIterator() {}
};
#endif /* STRING_BASE_H */