scummvm/common/str.h

/* ScummVM - Scumm Interpreter
 * Copyright (C) 2002-2004 The ScummVM project
 *
 * This program 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; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * $Header$
 */

#ifndef COMMON_STRING_H
#define COMMON_STRING_H

#include "common/scummsys.h"
#include "common/array.h"

#include <assert.h>
#include <string.h>

namespace Common {

/*
 TODO
 Add a class ConstString which is a light weight base class of String.
 It will be immutable, and *not* copy the char pointer it gets when created.
 Only constructor: ConstString(const char *ptr)
 Then whenever you now use "const String &" in a parameter, use "const ConstString &"
 instead (mayhaps make a typedef even). Thus, parameters are passed w/o 
 causing a free/malloc. Then only for permanent storage, when we assign it to a
 real String object, will a malloc be issued (to this end, make String aware of
 ConstString ?!?
*/

class ConstString {
	friend class String;
protected:
	char	*_str;
	int		_len;

public:
	ConstString() : _str(0), _len(0) {}
//	ConstString(const char *str, int len = -1) : _str((char *)str) { _len = str ? (len >= 0 ? len : strlen(str)) : 0; }
	virtual ~ConstString() {}
	
	bool operator ==(const ConstString &x) const;
	bool operator ==(const char *x) const;
	bool operator !=(const ConstString &x) const;
	bool operator !=(const char *x) const;
	bool operator <(const ConstString &x) const;
	bool operator <=(const ConstString &x) const;
	bool operator >(const ConstString &x) const;
	bool operator >=(const ConstString &x) const;

	char operator [](int idx) const {
		assert(_str && idx >= 0 && idx < _len);
		return _str[idx];
	}

	const char *c_str() const		{ return _str ? _str : ""; }
	uint size() const				{ return _len; }

	bool isEmpty() const	{ return (_len == 0); }
	char lastChar() const	{ return (_len > 0) ? _str[_len-1] : 0; }
};

class String : public ConstString {
protected:
	int *_refCount;
	int _capacity;

public:
	static const String emptyString;

	String() : _capacity(0) { _refCount = new int(1); }
	String(const char *str, int len = -1);
	String(const ConstString &str);
	String(const String &str);
	virtual ~String();
	
	String &operator  =(const char *str);
// TODO - We should use RTTI here - that is, not real C++ RTTI but maybe some magic
// constant in each string object. We want to be able to optimize the case when
// a real 'String' object is passed to a function as a ConstString obj and then
// assigned to a 'String' object.
// An alternative would be to add private clone() and cloneMutable methods that 
// would do the right thing.
	String &operator  =(const String &str);
	String &operator  =(char c);
	String &operator +=(const char *str);
	String &operator +=(const String &str);
	String &operator +=(char c);

	char operator [](int idx) const {
		assert(_str && idx >= 0 && idx < _len);
		return _str[idx];
	}

	char &operator [](int idx) {
		assert(_str && idx >= 0 && idx < _len);
		return _str[idx];
	}

	void deleteLastChar();
	void deleteChar(int p);
	void clear();
	void insertChar(char c, int p);

	void toLowercase();
	void toUppercase();

protected:
	void ensureCapacity(int new_len, bool keep_old);
	void decRefCount();
};

// Append two strings to form a new (temp) string
String operator +(const String &x, const String &y);
String operator +(const char *x, const String &y);
String operator +(const String &x, const char *y);

// Some useful additional comparision operators for Strings
bool operator == (const char *x, const ConstString &y);
bool operator != (const char *x, const ConstString &y);

class StringList : public Array<String> {
public:
	void push_back(const char *str) {
		ensureCapacity(_size + 1);
		_data[_size++] = str;
	}

	void push_back(const ConstString &str) {
		ensureCapacity(_size + 1);
		_data[_size++] = str;
	}
	
	void push_back(const String &str) {
		ensureCapacity(_size + 1);
		_data[_size++] = str;
	}
};

}	// End of namespace Common

#endif