string_manip.h

LibTorrent is a BitTorrent library written in C++ for *nix, with a focus on high performance and goo

// rak - Rakshasa's toolbox
// Copyright (C) 2005-2006, Jari Sundell
//
// 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
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// 
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// 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
//
// In addition, as a special exception, the copyright holders give
// permission to link the code of portions of this program with the
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// individual source file, and distribute linked combinations
// including the two.
//
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#ifndef RAK_STRING_MANIP_H
#define RAK_STRING_MANIP_H

#include <algorithm>
#include <cctype>
#include <cstdlib>
#include <iterator>
#include <locale>

namespace rak {

// Use these trim functions until n1872 is widely supported.

template <typename Sequence>
Sequence trim_begin(const Sequence& seq) {
  if (seq.empty() || !std::isspace(*seq.begin()))
    return seq;

  typename Sequence::size_type pos = 0;

  while (pos != seq.length() && std::isspace(seq[pos]))
    pos++;

  return seq.substr(pos, seq.length() - pos);
}

template <typename Sequence>
Sequence trim_end(const Sequence& seq) {
  if (seq.empty() || !std::isspace(*(--seq.end())))
    return seq;

  typename Sequence::size_type pos = seq.size();

  while (pos != 0 && std::isspace(seq[pos - 1]))
    pos--;

  return seq.substr(0, pos);
}

template <typename Sequence>
Sequence trim(const Sequence& seq) {
  return trim_begin(trim_end(seq));
}

template <typename Sequence>
Sequence trim_begin_classic(const Sequence& seq) {
  if (seq.empty() || !std::isspace(*seq.begin(), std::locale::classic()))
    return seq;

  typename Sequence::size_type pos = 0;

  while (pos != seq.length() && std::isspace(seq[pos], std::locale::classic()))
    pos++;

  return seq.substr(pos, seq.length() - pos);
}

template <typename Sequence>
Sequence trim_end_classic(const Sequence& seq) {
  if (seq.empty() || !std::isspace(*(--seq.end()), std::locale::classic()))
    return seq;

  typename Sequence::size_type pos = seq.size();

  while (pos != 0 && std::isspace(seq[pos - 1], std::locale::classic()))
    pos--;

  return seq.substr(0, pos);
}

template <typename Sequence>
Sequence trim_classic(const Sequence& seq) {
  return trim_begin_classic(trim_end_classic(seq));
}

// Consider rewritting such that m_seq is replaced by first/last.
template <typename Sequence>
class split_iterator_t {
public:
  typedef typename Sequence::const_iterator const_iterator;
  typedef typename Sequence::value_type     value_type;

  split_iterator_t() {}

  split_iterator_t(const Sequence& seq, value_type delim) :
    m_seq(&seq),
    m_delim(delim),
    m_pos(seq.begin()),
    m_next(std::find(seq.begin(), seq.end(), delim)) {
  }

  Sequence operator * () { return Sequence(m_pos, m_next); }

  split_iterator_t& operator ++ () {
    m_pos = m_next;

    if (m_pos == m_seq->end())
      return *this;

    m_pos++;
    m_next = std::find(m_pos, m_seq->end(), m_delim);

    return *this;
  }

  bool operator == (__UNUSED const split_iterator_t& itr) const { return m_pos == m_seq->end(); }
  bool operator != (__UNUSED const split_iterator_t& itr) const { return m_pos != m_seq->end(); }

private:
  const Sequence* m_seq;
  value_type      m_delim;
  const_iterator  m_pos;
  const_iterator  m_next;
};

template <typename Sequence>
inline split_iterator_t<Sequence>
split_iterator(const Sequence& seq, typename Sequence::value_type delim) {
  return split_iterator_t<Sequence>(seq, delim);
}

template <typename Sequence>
inline split_iterator_t<Sequence>
split_iterator(__UNUSED const Sequence& seq) {
  return split_iterator_t<Sequence>();
}

// Could optimize this abit.
inline char
hexchar_to_value(char c) {
  if (c >= '0' && c <= '9')
    return c - '0';

  else if (c >= 'A' && c <= 'F')
    return 10 + c - 'A';
    
  else
    return 10 + c - 'a';
}

template <int pos, typename Value>
inline char
value_to_hexchar(Value v) {
  v >>= pos * 4;
  v &= 0xf;

  if (v < 0xA)
    return '0' + v;
  else
    return 'A' + v - 0xA;
}

template <typename InputIterator, typename OutputIterator> 
OutputIterator
copy_escape_html(InputIterator first, InputIterator last, OutputIterator dest) {
  while (first != last) {
    if (std::isalpha(*first, std::locale::classic()) ||
        std::isdigit(*first, std::locale::classic()) ||
        *first == '-') {
      *(dest++) = *first;

    } else {
      *(dest++) = '%';
      *(dest++) = value_to_hexchar<1>(*first);
      *(dest++) = value_to_hexchar<0>(*first);
    }

    ++first;
  }

  return dest;
}

template <typename InputIterator, typename OutputIterator> 
OutputIterator
copy_escape_html(InputIterator first1, InputIterator last1, OutputIterator first2, OutputIterator last2) {
  while (first1 != last1) {
    if (std::isalpha(*first1, std::locale::classic()) ||
        std::isdigit(*first1, std::locale::classic()) ||
        *first1 == '-') {
      if (first2 == last2) break; else *(first2++) = *first1;

    } else {
      if (first2 == last2) break; else *(first2++) = '%';
      if (first2 == last2) break; else *(first2++) = value_to_hexchar<1>(*first1);
      if (first2 == last2) break; else *(first2++) = value_to_hexchar<0>(*first1);
    }

    ++first1;
  }

  return first2;
}

template <typename Sequence>
Sequence
copy_escape_html(const Sequence& src) {
  Sequence dest;
  copy_escape_html(src.begin(), src.end(), std::back_inserter(dest));

  return dest;
}

// Consider support for larger than char type.
template <typename InputIterator, typename OutputIterator> 
OutputIterator
transform_hex(InputIterator first, InputIterator last, OutputIterator dest) {
  while (first != last) {
    *(dest++) = value_to_hexchar<1>(*first);
    *(dest++) = value_to_hexchar<0>(*first);

    ++first;
  }

  return dest;
}

template <typename InputIterator, typename OutputIterator> 
OutputIterator
transform_hex(InputIterator first1, InputIterator last1, OutputIterator first2, OutputIterator last2) {
  while (first1 != last1) {
    if (first2 == last2) break; else *(first2++) = value_to_hexchar<1>(*first1);
    if (first2 == last2) break; else *(first2++) = value_to_hexchar<0>(*first1);

    ++first1;
  }

  return first2;
}

template <typename Sequence>
Sequence
transform_hex(const Sequence& src) {
  Sequence dest;
  transform_hex(src.begin(), src.end(), std::back_inserter(dest));

  return dest;
}

template <typename Sequence>
Sequence
generate_random(size_t length) {
  Sequence s;
  s.reserve(length);

  std::generate_n(std::back_inserter(s), length, &::random);

  return s;
}

}

#endif