ext_string.rar_ext_string_字符串分割

/** * @mainpage Extended STL string * @author Keenan Tims - ktims@gotroot.ca * @version 0.2 * @date 2005-04-17 * @section desc Description * ext_string aims to provide a portable, bug-free implementation of many useful extensions to the * standard STL string class. These extensions are commonly available among higher-level languages * such as Perl and Python, but C++ programmers are generally left on their own when it comes to * basic string processing. By extending the STL's string, we can provide a drop-in replacement for STL * strings with the greater functionality of higher-level languages. * * The primary goal of this library is to make the STL string class more usable to programmers that * are doing simple string manipulation on a small scale. Due to the usability goals of this class, * many actions will be inefficiently implemented for the sake of ease of use. Some of this is * mitigated somewhat by doing modification in-place, however many unnecessary copies of data are * created by some methods, and the vector-returning methods are inefficient in that they copy the * substrings into the vector, then return a copy of the vector. This would be much more efficient * as an iterator model. * * * @section feat Features * * @li Fully based on the STL, ext_string provides a superset of std::string methods * @li String splitting (tokenizing), on a character, a string, or whitespace * @li Replacement of substrings or characters with another string or character * @li String case operations (check, adjust) * @li Integer conversion * @li Fully open-source under a BSD-like license for use in any product * * @if web * @section download Downloads * * Downloads are provided in tar.gz and zip formats containing this documentation, the header file, * and the library's changelog. The latest version of ext_string is 0.2, released on April 17, * 2005. * * @li<a href="files/ext_string-0.2.tar.gz">ext_string-0.2.tar.gz</a> * @li<a href="files/ext_string-0.2.zip">ext_string-0.2.zip</a> * @li <small><a href="files/ext_string-0.1.tar.gz">ext_string-0.1.tar.gz</a></small> * @li <small><a href="files/ext_string-0.1.zip">ext_string-0.1.zip</a></small> * * @section changelog Changelog * * The changelog is viewable online <a href="files/CHANGELOG">here</a> * * @endif * * @section notes Notes/Limitations * @li Copying all the substrings into a vector for the substring methods is pretty inefficient, * both for space and time. It would be more prudent to model an iterator to split the string based * on the specified parameters, but this is more difficult to implement and more cumbersome to use. * Performance is not the main goal of this library, usability is, thus the tradeoff is deemed to be * acceptable. * @li References are not used too aptly in this class. Some performance tuning could be done to * minimize unnecessary data copying. * @li The basic methods of std::string aren't overridden by this class, thus assigning the return * value of eg. string::insert() to an ext_string instance will make an unnecessary string object * which is then copy-constructed to an ext_string (I believe, internal workings of inheritance and * polymorphism in C++ are somewhat beyond my experience). These methods should be wrapped by * ext_string to return the proper type. * * * @section related Related Documentation * * @li SGI's STL string reference: http://www.sgi.com/tech/stl/basic_string.html * * * @section license License * * Copyright (c) 2005, Keenan Tims * All rights reserved. * * Redistribution and use in source and binary forms, with or without modification, are permitted * provided that the following conditions are met: * @li Redistributions of source code must retain the above copyright notice, this list of * conditions and the following disclaimer. * @li Redistributions in binary form must reproduce the above copyright notice, this list of * conditions and the following disclaimer in the documentation and/or other materials provided with * the distribution. * @li Neither the name of the Extended STL String project nor the names of its contributors may be used to endorse * or promote products derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTIBILITY AND * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * */ #ifndef _EXT_STRING_H #define _EXT_STRING_H #include <string> #include <vector> namespace std { /** * An extension of STL's string providing additional functionality that is often availiable in * higher-level languages such as Python. */ class ext_string : public string { public: /** * Default constructor * * Constructs an empty ext_string ("") */ ext_string() : string() { } /** * Duplicate the STL string copy constructor * * @param[in] s The string to copy * @param[in] pos The starting position in the string to copy from * @param[in] n The number of characters to copy */ ext_string(const string &s, size_type pos = 0, size_type n = npos) : string(s, pos, npos) { } /** * Construct an ext_string from a null-terminated character array * * @param[in] s The character array to copy into the new string */ ext_string(const value_type *s) : string(s) { } /** * Construct an ext_string from a character array and a length * * @param[in] s The character array to copy into the new string * @param[in] n The number of characters to copy */ ext_string(const value_type *s, size_type n) : string(s, n) { } /** * Create an ext_string with @p n copies of @p c * * @param[in] n The number of copies * @param[in] c The character to copy @p n times */ ext_string(size_type n, value_type c) : string(n, c) { } /** * Create a string from a range * * @param[in] first The first element to copy in * @param[in] last The last element to copy in */ template <class InputIterator> ext_string(InputIterator first, InputIterator last) : string(first, last) { } /** * The destructor */ ~ext_string() { } /** * Split a string by whitespace * * @return A vector of strings, each of which is a substring of the string */ vector<ext_string> split(size_type limit = npos) const { vector<ext_string> v; const_iterator i = begin(), last = i; for (; i != end(); i++) { if (*i == ' ' || *i == '\n' || *i == '\t' || *i == '\r') { if (i + 1 != end() && (i[1] == ' ' || i[1] == '\n' || i[1] == '\t' || i[1] == '\r')) continue; v.push_back(ext_string(last, i)); last = i + 1; if (v.size() >= limit - 1) { v.push_back(ext_string(last, end())); return v; } } } if (last != i) v.push_back(ext_string(last, i)); return v; } /** * Split a string by a character * * Returns a vector of ext_strings, each of which is a substring of the string formed by splitting * it on boundaries formed by the character @p separator. If @p limit is set, the returned vector * will contain a maximum of @p limit elements with the last element containing the rest of * the string. *