scummvm/common/tokenizer.cpp
2020-09-03 02:21:14 +02:00

105 lines
3.5 KiB
C++

/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*/
#include "common/tokenizer.h"
namespace Common {
StringTokenizer::StringTokenizer(const String &str, const String &delimiters) : _str(str), _delimiters(delimiters) {
reset();
}
void StringTokenizer::reset() {
_tokenBegin = _tokenEnd = 0;
}
bool StringTokenizer::empty() const {
// Search for the next token's start (i.e. the next non-delimiter character)
for (uint i = _tokenEnd; i < _str.size(); i++) {
if (!_delimiters.contains(_str[i]))
return false; // Found a token so the tokenizer is not empty
}
// Didn't find any more tokens so the tokenizer is empty
return true;
}
String StringTokenizer::nextToken() {
// Seek to next token's start (i.e. jump over the delimiters before next token)
for (_tokenBegin = _tokenEnd; _tokenBegin < _str.size() && _delimiters.contains(_str[_tokenBegin]); _tokenBegin++)
;
// Seek to the token's end (i.e. jump over the non-delimiters)
for (_tokenEnd = _tokenBegin; _tokenEnd < _str.size() && !_delimiters.contains(_str[_tokenEnd]); _tokenEnd++)
;
// Return the found token
return String(_str.c_str() + _tokenBegin, _tokenEnd - _tokenBegin);
}
U32StringTokenizer::U32StringTokenizer(const U32String &str, const String &delimiters) : _str(str), _delimiters(delimiters) {
reset();
}
void U32StringTokenizer::reset() {
_tokenBegin = _tokenEnd = _str.begin();
}
bool U32StringTokenizer::empty() const {
// Search for the next token's start (i.e. the next non-delimiter character)
for (U32String::const_iterator itr = _tokenEnd; itr != _str.end(); itr++) {
if (!_delimiters.contains(*itr)) {
return false; // Found a token so the tokenizer is not empty
}
}
// Didn't find any more tokens so the tokenizer is empty
return true;
}
U32String U32StringTokenizer::nextToken() {
// Skip delimiters when present at the beginning, to point to the next token
// For example, the below loop will set _tokenBegin & _tokenEnd to 'H' for the string -> "!!--=Hello World"
// And subsequently, skip all delimiters in the beginning of the next word.
while (_tokenBegin != _str.end() && _delimiters.contains(*_tokenBegin)) {
_tokenBegin++;
_tokenEnd++;
}
// Loop and advance _tokenEnd until we find a delimiter at the end of a word/string
while (_tokenBegin != _str.end() && _tokenEnd != _str.end()) {
if (_delimiters.contains(*_tokenEnd)) {
U32String token(_tokenBegin, _tokenEnd);
_tokenEnd++;
_tokenBegin = _tokenEnd;
return token;
}
_tokenEnd++;
}
// Returning the last word if _tokenBegin iterator isn't at the end.
if (_tokenBegin != _str.end())
return U32String(_tokenBegin, _tokenEnd);
else
return U32String();
}
} // End of namespace Common