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/*
Ousía
Copyright (C) 2014 Benjamin Paaßen, Andreas Stöckel
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 3 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, see <http://www.gnu.org/licenses/>.
*/
/**
* @file Whitespace.hpp
*
* Contains the WhitespaceMode enum used in various places, as well es functions
* for trimming and collapsing whitespaces.
*
* @author Andreas Stöckel (astoecke@techfak.uni-bielefeld.de)
*/
#ifndef _OUSIA_WHITESPACE_HPP_
#define _OUSIA_WHITESPACE_HPP_
#include <string>
#include <utility>
namespace ousia {
/**
* Enum specifying the whitespace handling mode of the tokenizer and the
* parsers.
*/
enum class WhitespaceMode {
/**
* Preserves all whitespaces as they are found in the source file.
*/
PRESERVE,
/**
* Trims whitespace at the beginning and the end of the found text.
*/
TRIM,
/**
* Whitespaces are trimmed and collapsed, multiple whitespace characters
* are replaced by a single space character.
*/
COLLAPSE
};
/**
* Collection of functions for trimming or collapsing whitespace.
*/
class Whitespace {
/**
* Removes whitespace at the beginning and the end of the given string.
*
* @param s is the string that should be trimmed.
* @return a trimmed copy of s.
*/
static std::string trim(const std::string &s);
/**
* Trims the given string or vector of chars by returning the start and end
* index.
*
* @param s is the container that should be trimmed.
* @param f is a function that returns true for values that should be
* removed.
* @return start and end index. Note that "end" points at the character
* beyond the end, thus "end" minus "start"
*/
template <class T, class Filter>
static std::pair<size_t, size_t> trim(const T &s, Filter f)
{
size_t start = 0;
for (size_t i = 0; i < s.size(); i++) {
if (!f(s[i])) {
start = i;
break;
}
}
size_t end = 0;
for (ssize_t i = s.size() - 1; i >= static_cast<ssize_t>(start); i--) {
if (!f(s[i])) {
end = i + 1;
break;
}
}
if (end < start) {
start = 0;
end = 0;
}
return std::pair<size_t, size_t>{start, end};
}
/**
* Collapses the whitespaces in the given string (trims the string and
* replaces all whitespace characters by a single one).
*
* @param s is the string in which the whitespace should be collapsed.
* @return a copy of s with collapsed whitespace.
*/
static std::string collapse(const std::string &s);
};
}
#endif /* _OUSIA_WHITESPACE_HPP_ */
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