1
    2
    3
    4
    5
    6
    7
    8
    9
   10
   11
   12
   13
   14
   15
   16
   17
   18
   19
   20
   21
   22
   23
   24
   25
   26
   27
   28
   29
   30
   31
   32
   33
   34
   35
   36
   37
   38
   39
   40
   41
   42
   43
   44
   45
   46
   47
   48
   49
   50
   51
   52
   53
   54
   55
   56
   57
   58
   59
   60
   61
   62
   63
   64
   65
   66
   67
   68
   69
   70
   71
   72
   73
   74
   75
   76
   77
   78
   79
   80
   81
   82
   83
   84
   85
   86
   87
   88
   89
   90
   91
   92
   93
   94
   95
   96
   97
   98
   99
  100
  101
  102
  103

base / strings / string_split_internal.h [blame]

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef BASE_STRINGS_STRING_SPLIT_INTERNAL_H_
#define BASE_STRINGS_STRING_SPLIT_INTERNAL_H_

#include <string_view>
#include <vector>

#include "base/strings/string_util.h"

namespace base {

namespace internal {

// Returns either the ASCII or UTF-16 whitespace.
template <typename CharT>
std::basic_string_view<CharT> WhitespaceForType();

template <>
inline std::u16string_view WhitespaceForType<char16_t>() {
  return kWhitespaceUTF16;
}
template <>
inline std::string_view WhitespaceForType<char>() {
  return kWhitespaceASCII;
}

// General string splitter template. Can take 8- or 16-bit input, can produce
// the corresponding string or std::string_view output.
template <typename OutputStringType,
          typename T,
          typename CharT = typename T::value_type>
static std::vector<OutputStringType> SplitStringT(T str,
                                                  T delimiter,
                                                  WhitespaceHandling whitespace,
                                                  SplitResult result_type) {
  std::vector<OutputStringType> result;
  if (str.empty())
    return result;

  size_t start = 0;
  while (start != std::basic_string<CharT>::npos) {
    size_t end = str.find_first_of(delimiter, start);

    std::basic_string_view<CharT> piece;
    if (end == std::basic_string<CharT>::npos) {
      piece = str.substr(start);
      start = std::basic_string<CharT>::npos;
    } else {
      piece = str.substr(start, end - start);
      start = end + 1;
    }

    if (whitespace == TRIM_WHITESPACE)
      piece = TrimString(piece, WhitespaceForType<CharT>(), TRIM_ALL);

    if (result_type == SPLIT_WANT_ALL || !piece.empty())
      result.emplace_back(piece);
  }
  return result;
}

template <typename OutputStringType,
          typename T,
          typename CharT = typename T::value_type>
std::vector<OutputStringType> SplitStringUsingSubstrT(
    T input,
    T delimiter,
    WhitespaceHandling whitespace,
    SplitResult result_type) {
  using Piece = std::basic_string_view<CharT>;
  using size_type = typename Piece::size_type;

  std::vector<OutputStringType> result;
  if (delimiter.size() == 0) {
    result.emplace_back(input);
    return result;
  }

  for (size_type begin_index = 0, end_index = 0; end_index != Piece::npos;
       begin_index = end_index + delimiter.size()) {
    end_index = input.find(delimiter, begin_index);
    Piece term = end_index == Piece::npos
                     ? input.substr(begin_index)
                     : input.substr(begin_index, end_index - begin_index);

    if (whitespace == TRIM_WHITESPACE)
      term = TrimString(term, WhitespaceForType<CharT>(), TRIM_ALL);

    if (result_type == SPLIT_WANT_ALL || !term.empty())
      result.emplace_back(term);
  }

  return result;
}

}  // namespace internal

}  // namespace base

#endif  // BASE_STRINGS_STRING_SPLIT_INTERNAL_H_