| 68 | */ |
| 69 | template<class... ARGS> |
| 70 | std::string format(std::string_view fmt, ARGS... args) { |
| 71 | std::vector<std::string> argVec = {toFormatString<ARGS>(args)...}; |
| 72 | |
| 73 | enum class ParseState { |
| 74 | Normal, |
| 75 | LeftBrace, |
| 76 | RightBrace |
| 77 | } state = ParseState::Normal; |
| 78 | |
| 79 | std::vector<FormatReplaceExpress> replaceExpresses; |
| 80 | |
| 81 | |
| 82 | std::size_t leftBraceBegin = 0; |
| 83 | |
| 84 | std::size_t rightBraceBegin = 0; |
| 85 | |
| 86 | // 如果在表达式中出现左大括号 |
| 87 | std::size_t exprLeftCount = 0; |
| 88 | |
| 89 | |
| 90 | for (std::size_t index = 0; index != fmt.size(); index++) { |
| 91 | char ch = fmt[index]; |
| 92 | |
| 93 | switch (state) { |
| 94 | case ParseState::Normal: { |
| 95 | if (ch == '{') { |
| 96 | state = ParseState::LeftBrace; |
| 97 | leftBraceBegin = index; |
| 98 | exprLeftCount = 0; |
| 99 | } else if (ch == '}') { |
| 100 | state = ParseState::RightBrace; |
| 101 | rightBraceBegin = index; |
| 102 | } |
| 103 | break; |
| 104 | } |
| 105 | case ParseState::LeftBrace: { |
| 106 | if (ch == '{') { |
| 107 | // 认为是左双大括号转义为可见的'{' |
| 108 | if (index == leftBraceBegin + 1) { |
| 109 | replaceExpresses.emplace_back("{", leftBraceBegin, index, false); |
| 110 | state = ParseState::Normal; |
| 111 | } else { |
| 112 | exprLeftCount++; |
| 113 | } |
| 114 | } else if (ch == '}') { |
| 115 | // 认为是表达式内的大括号 |
| 116 | if (exprLeftCount > 0) { |
| 117 | exprLeftCount--; |
| 118 | continue; |
| 119 | } |
| 120 | |
| 121 | replaceExpresses.emplace_back(fmt.substr(leftBraceBegin + 1, index - leftBraceBegin - 1), |
| 122 | leftBraceBegin, index, true); |
| 123 | |
| 124 | |
| 125 | state = ParseState::Normal; |
| 126 | } |
| 127 | break; |