mirror of
https://github.com/ToruNiina/toml11.git
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813 lines
27 KiB
C++
813 lines
27 KiB
C++
// Copyright Toru Niina 2019.
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// Distributed under the MIT License.
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#ifndef TOML11_SERIALIZER_HPP
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#define TOML11_SERIALIZER_HPP
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#include "value.hpp"
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#include "lexer.hpp"
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#include <limits>
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#include <cstdio>
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namespace toml
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{
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// This function serialize a key. It checks a string is a bare key and
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// escapes special characters if the string is not compatible to a bare key.
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// ```cpp
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// std::string k("non.bare.key"); // the key itself includes `.`s.
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// std::string formatted = toml::format_key(k);
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// assert(formatted == "\"non.bare.key\"");
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// ```
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//
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// This function is exposed to make it easy to write a user-defined serializer.
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// Since toml restricts characters available in a bare key, generally a string
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// should be escaped. But checking whether a string needs to be surrounded by
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// a `"` and escaping some special character is boring.
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inline std::string format_key(const toml::key& key)
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{
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detail::location<toml::key> loc(key, key);
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detail::lex_unquoted_key::invoke(loc);
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if(loc.iter() == loc.end())
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{
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return key; // all the tokens are consumed. the key is unquoted-key.
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}
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std::string token("\"");
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for(const char c : key)
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{
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switch(c)
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{
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case '\\': {token += "\\\\"; break;}
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case '\"': {token += "\\\""; break;}
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case '\b': {token += "\\b"; break;}
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case '\t': {token += "\\t"; break;}
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case '\f': {token += "\\f"; break;}
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case '\n': {token += "\\n"; break;}
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case '\r': {token += "\\r"; break;}
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default : {token += c; break;}
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}
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}
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token += "\"";
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return token;
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}
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template<typename Comment,
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template<typename ...> class Table,
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template<typename ...> class Array>
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struct serializer
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{
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using value_type = basic_value<Comment, Table, Array>;
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using key_type = typename value_type::key_type ;
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using comment_type = typename value_type::comment_type ;
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using boolean_type = typename value_type::boolean_type ;
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using integer_type = typename value_type::integer_type ;
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using floating_type = typename value_type::floating_type ;
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using string_type = typename value_type::string_type ;
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using local_time_type = typename value_type::local_time_type ;
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using local_date_type = typename value_type::local_date_type ;
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using local_datetime_type = typename value_type::local_datetime_type ;
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using offset_datetime_type = typename value_type::offset_datetime_type;
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using array_type = typename value_type::array_type ;
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using table_type = typename value_type::table_type ;
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serializer(const std::size_t w = 80u,
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const int float_prec = std::numeric_limits<toml::floating>::max_digits10,
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const bool can_be_inlined = false,
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const bool no_comment = false,
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std::vector<toml::key> ks = {})
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: can_be_inlined_(can_be_inlined), no_comment_(no_comment),
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float_prec_(float_prec), width_(w), keys_(std::move(ks))
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{}
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~serializer() = default;
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std::string operator()(const boolean_type& b) const
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{
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return b ? "true" : "false";
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}
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std::string operator()(const integer_type i) const
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{
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return std::to_string(i);
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}
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std::string operator()(const floating_type f) const
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{
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const auto fmt = "%.*g";
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const auto bsz = std::snprintf(nullptr, 0, fmt, this->float_prec_, f);
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// +1 for null character(\0)
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std::vector<char> buf(static_cast<std::size_t>(bsz + 1), '\0');
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std::snprintf(buf.data(), buf.size(), fmt, this->float_prec_, f);
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std::string token(buf.begin(), std::prev(buf.end()));
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if(token.back() == '.') // 1. => 1.0
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{
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token += '0';
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}
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const auto e = std::find_if(
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token.cbegin(), token.cend(), [](const char c) noexcept -> bool {
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return c == 'e' || c == 'E';
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});
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const auto has_exponent = (token.cend() != e);
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const auto has_fraction = (token.cend() != std::find(
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token.cbegin(), token.cend(), '.'));
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if(!has_exponent && !has_fraction)
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{
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// the resulting value does not have any float specific part!
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token += ".0";
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return token;
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}
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if(!has_exponent)
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{
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return token; // there is no exponent part. just return it.
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}
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#ifdef TOML11_USE_UNRELEASED_TOML_FEATURES
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// Although currently it is not released yet as a tagged version,
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// TOML will allow zero-prefix in an exponent part, such as `1.234e+01`.
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// ```toml
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// num1 = 1.234e+1 # OK in TOML v0.5.0
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// num2 = 1.234e+01 # error in TOML v0.5.0 but will be allowed soon
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// ```
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// To avoid `e+01`, the following `else` section removes the zero
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// prefixes in the exponent part.
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// If the feature is activated, it can be skipped.
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return token;
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#else
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// zero-prefix in an exponent is NOT allowed in TOML v0.5.0.
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// remove it if it exists.
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bool sign_exists = false;
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std::size_t zero_prefix = 0;
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for(auto iter = std::next(e), iend = token.cend(); iter != iend; ++iter)
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{
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if(*iter == '+' || *iter == '-'){sign_exists = true; continue;}
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if(*iter == '0'){zero_prefix += 1;}
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else {break;}
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}
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if(zero_prefix != 0)
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{
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const auto offset = std::distance(token.cbegin(), e) +
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(sign_exists ? 2 : 1);
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token.erase(static_cast<typename std::string::size_type>(offset),
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zero_prefix);
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}
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return token;
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#endif
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}
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std::string operator()(const string_type& s) const
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{
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if(s.kind == string_t::basic)
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{
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if(std::find(s.str.cbegin(), s.str.cend(), '\n') != s.str.cend() ||
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std::find(s.str.cbegin(), s.str.cend(), '\"') != s.str.cend())
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{
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// if linefeed or double-quote is contained,
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// make it multiline basic string.
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const auto escaped = this->escape_ml_basic_string(s.str);
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std::string open("\"\"\"");
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std::string close("\"\"\"");
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if(escaped.find('\n') != std::string::npos ||
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this->width_ < escaped.size() + 6)
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{
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// if the string body contains newline or is enough long,
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// add newlines after and before delimiters.
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open += "\n";
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close = std::string("\\\n") + close;
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}
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return open + escaped + close;
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}
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// no linefeed. try to make it oneline-string.
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std::string oneline = this->escape_basic_string(s.str);
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if(oneline.size() + 2 < width_ || width_ < 2)
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{
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const std::string quote("\"");
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return quote + oneline + quote;
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}
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// the line is too long compared to the specified width.
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// split it into multiple lines.
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std::string token("\"\"\"\n");
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while(!oneline.empty())
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{
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if(oneline.size() < width_)
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{
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token += oneline;
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oneline.clear();
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}
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else if(oneline.at(width_-2) == '\\')
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{
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token += oneline.substr(0, width_-2);
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token += "\\\n";
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oneline.erase(0, width_-2);
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}
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else
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{
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token += oneline.substr(0, width_-1);
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token += "\\\n";
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oneline.erase(0, width_-1);
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}
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}
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return token + std::string("\\\n\"\"\"");
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}
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else // the string `s` is literal-string.
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{
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if(std::find(s.str.cbegin(), s.str.cend(), '\n') != s.str.cend() ||
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std::find(s.str.cbegin(), s.str.cend(), '\'') != s.str.cend() )
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{
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std::string open("'''");
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if(this->width_ + 6 < s.str.size())
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{
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open += '\n'; // the first newline is ignored by TOML spec
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}
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const std::string close("'''");
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return open + s.str + close;
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}
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else
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{
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const std::string quote("'");
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return quote + s.str + quote;
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}
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}
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}
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std::string operator()(const local_date_type& d) const
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{
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std::ostringstream oss;
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oss << d;
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return oss.str();
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}
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std::string operator()(const local_time_type& t) const
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{
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std::ostringstream oss;
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oss << t;
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return oss.str();
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}
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std::string operator()(const local_datetime_type& dt) const
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{
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std::ostringstream oss;
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oss << dt;
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return oss.str();
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}
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std::string operator()(const offset_datetime_type& odt) const
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{
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std::ostringstream oss;
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oss << odt;
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return oss.str();
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}
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std::string operator()(const array_type& v) const
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{
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if(!v.empty() && v.front().is_table())// v is an array of tables
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{
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// if it's not inlined, we need to add `[[table.key]]`.
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// but if it can be inlined,
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// ```
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// table.key = [
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// {...},
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// # comment
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// {...},
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// ]
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// ```
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if(this->can_be_inlined_)
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{
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std::string token;
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if(!keys_.empty())
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{
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token += this->serialize_key(keys_.back());
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token += " = ";
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}
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bool failed = false;
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token += "[\n";
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for(const auto& item : v)
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{
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// if an element of the table has a comment, the table
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// cannot be inlined.
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if(this->has_comment_inside(item.as_table()))
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{
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failed = true;
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break;
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}
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if(!no_comment_)
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{
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for(const auto& c : item.comments())
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{
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token += '#';
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token += c;
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token += '\n';
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}
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}
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const auto t = this->make_inline_table(item.as_table());
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if(t.size() + 1 > width_ || // +1 for the last comma {...},
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std::find(t.cbegin(), t.cend(), '\n') != t.cend())
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{
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failed = true;
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break;
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}
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token += t;
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token += ",\n";
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}
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if(!failed)
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{
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token += "]\n";
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return token;
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}
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// if failed, serialize them as [[array.of.tables]].
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}
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std::string token;
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for(const auto& item : v)
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{
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if(!no_comment_)
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{
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for(const auto& c : item.comments())
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{
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token += '#';
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token += c;
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token += '\n';
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}
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}
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token += "[[";
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token += this->serialize_dotted_key(keys_);
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token += "]]\n";
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token += this->make_multiline_table(item.as_table());
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}
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return token;
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}
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if(v.empty())
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{
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return std::string("[]");
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}
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// not an array of tables. normal array.
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// first, try to make it inline if none of the elements have a comment.
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if(!this->has_comment_inside(v))
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{
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const auto inl = this->make_inline_array(v);
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if(inl.size() < this->width_ &&
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std::find(inl.cbegin(), inl.cend(), '\n') == inl.cend())
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{
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return inl;
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}
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}
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// if the length exceeds this->width_, print multiline array.
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// key = [
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// # ...
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// 42,
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// ...
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// ]
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std::string token;
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std::string current_line;
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token += "[\n";
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for(const auto& item : v)
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{
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if(!item.comments().empty() && !no_comment_)
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{
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// if comment exists, the element must be the only element in the line.
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// e.g. the following is not allowed.
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// ```toml
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// array = [
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// # comment for what?
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// 1, 2, 3, 4, 5
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// ]
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// ```
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if(!current_line.empty())
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{
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if(current_line.back() != '\n')
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{
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current_line += '\n';
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}
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token += current_line;
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current_line.clear();
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}
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for(const auto& c : item.comments())
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{
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token += '#';
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token += c;
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token += '\n';
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}
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token += toml::visit(*this, item);
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if(token.back() == '\n') {token.pop_back();}
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token += ",\n";
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continue;
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}
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std::string next_elem;
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next_elem += toml::visit(*this, item);
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// comma before newline.
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if(next_elem.back() == '\n') {next_elem.pop_back();}
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// if current line does not exceeds the width limit, continue.
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if(current_line.size() + next_elem.size() + 1 < this->width_)
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{
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current_line += next_elem;
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current_line += ',';
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}
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else if(current_line.empty())
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{
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// if current line was empty, force put the next_elem because
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// next_elem is not splittable
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token += next_elem;
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token += ",\n";
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// current_line is kept empty
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}
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else // reset current_line
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{
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assert(current_line.back() == ',');
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token += current_line;
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token += '\n';
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current_line = next_elem;
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current_line += ',';
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}
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}
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if(!current_line.empty())
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{
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if(current_line.back() != '\n') {current_line += '\n';}
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token += current_line;
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}
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token += "]\n";
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return token;
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}
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// templatize for any table-like container
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std::string operator()(const table_type& v) const
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{
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// if an element has a comment, then it can't be inlined.
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// table = {# how can we write a comment for this? key = "value"}
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if(this->can_be_inlined_ && !(this->has_comment_inside(v)))
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{
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std::string token;
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if(!this->keys_.empty())
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{
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token += this->serialize_key(this->keys_.back());
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token += " = ";
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}
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token += this->make_inline_table(v);
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if(token.size() < this->width_ &&
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token.end() == std::find(token.begin(), token.end(), '\n'))
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{
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return token;
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}
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}
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std::string token;
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if(!keys_.empty())
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{
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token += '[';
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token += this->serialize_dotted_key(keys_);
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token += "]\n";
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}
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token += this->make_multiline_table(v);
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return token;
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}
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private:
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std::string serialize_key(const toml::key& key) const
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{
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return ::toml::format_key(key);
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}
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std::string serialize_dotted_key(const std::vector<toml::key>& keys) const
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{
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std::string token;
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if(keys.empty()){return token;}
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for(const auto& k : keys)
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{
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token += this->serialize_key(k);
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token += '.';
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}
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token.erase(token.size() - 1, 1); // remove trailing `.`
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return token;
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}
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std::string escape_basic_string(const std::string& s) const
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{
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//XXX assuming `s` is a valid utf-8 sequence.
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std::string retval;
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for(const char c : s)
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{
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switch(c)
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{
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case '\\': {retval += "\\\\"; break;}
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case '\"': {retval += "\\\""; break;}
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case '\b': {retval += "\\b"; break;}
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case '\t': {retval += "\\t"; break;}
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case '\f': {retval += "\\f"; break;}
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case '\n': {retval += "\\n"; break;}
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case '\r': {retval += "\\r"; break;}
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default : {retval += c; break;}
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}
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}
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return retval;
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}
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std::string escape_ml_basic_string(const std::string& s) const
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{
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std::string retval;
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for(auto i=s.cbegin(), e=s.cend(); i!=e; ++i)
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{
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switch(*i)
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{
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case '\\': {retval += "\\\\"; break;}
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// One or two consecutive "s are allowed.
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// Later we will check there are no three consecutive "s.
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// case '\"': {retval += "\\\""; break;}
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case '\b': {retval += "\\b"; break;}
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case '\t': {retval += "\\t"; break;}
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case '\f': {retval += "\\f"; break;}
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case '\n': {retval += "\n"; break;}
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case '\r':
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{
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if(std::next(i) != e && *std::next(i) == '\n')
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{
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retval += "\r\n";
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++i;
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}
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else
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{
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retval += "\\r";
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}
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break;
|
|
}
|
|
default: {retval += *i; break;}
|
|
}
|
|
}
|
|
// Only 1 or 2 consecutive `"`s are allowed in multiline basic string.
|
|
// 3 consecutive `"`s are considered as a closing delimiter.
|
|
// We need to check if there are 3 or more consecutive `"`s and insert
|
|
// backslash to break them down into several short `"`s like the `str6`
|
|
// in the following example.
|
|
// ```toml
|
|
// str4 = """Here are two quotation marks: "". Simple enough."""
|
|
// # str5 = """Here are three quotation marks: """.""" # INVALID
|
|
// str5 = """Here are three quotation marks: ""\"."""
|
|
// str6 = """Here are fifteen quotation marks: ""\"""\"""\"""\"""\"."""
|
|
// ```
|
|
auto found_3_quotes = retval.find("\"\"\"");
|
|
while(found_3_quotes != std::string::npos)
|
|
{
|
|
retval.replace(found_3_quotes, 3, "\"\"\\\"");
|
|
found_3_quotes = retval.find("\"\"\"");
|
|
}
|
|
return retval;
|
|
}
|
|
|
|
// if an element of a table or an array has a comment, it cannot be inlined.
|
|
bool has_comment_inside(const array_type& a) const noexcept
|
|
{
|
|
// if no_comment is set, comments would not be written.
|
|
if(this->no_comment_) {return false;}
|
|
|
|
for(const auto& v : a)
|
|
{
|
|
if(!v.comments().empty()) {return true;}
|
|
}
|
|
return false;
|
|
}
|
|
bool has_comment_inside(const table_type& t) const noexcept
|
|
{
|
|
// if no_comment is set, comments would not be written.
|
|
if(this->no_comment_) {return false;}
|
|
|
|
for(const auto& kv : t)
|
|
{
|
|
if(!kv.second.comments().empty()) {return true;}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
std::string make_inline_array(const array_type& v) const
|
|
{
|
|
assert(!has_comment_inside(v));
|
|
std::string token;
|
|
token += '[';
|
|
bool is_first = true;
|
|
for(const auto& item : v)
|
|
{
|
|
if(is_first) {is_first = false;} else {token += ',';}
|
|
token += visit(serializer(std::numeric_limits<std::size_t>::max(),
|
|
this->float_prec_, true), item);
|
|
}
|
|
token += ']';
|
|
return token;
|
|
}
|
|
|
|
std::string make_inline_table(const table_type& v) const
|
|
{
|
|
assert(!has_comment_inside(v));
|
|
assert(this->can_be_inlined_);
|
|
std::string token;
|
|
token += '{';
|
|
bool is_first = true;
|
|
for(const auto& kv : v)
|
|
{
|
|
// in inline tables, trailing comma is not allowed (toml-lang #569).
|
|
if(is_first) {is_first = false;} else {token += ',';}
|
|
token += this->serialize_key(kv.first);
|
|
token += '=';
|
|
token += visit(serializer(std::numeric_limits<std::size_t>::max(),
|
|
this->float_prec_, true), kv.second);
|
|
}
|
|
token += '}';
|
|
return token;
|
|
}
|
|
|
|
std::string make_multiline_table(const table_type& v) const
|
|
{
|
|
std::string token;
|
|
|
|
// print non-table stuff first. because after printing [foo.bar], the
|
|
// remaining non-table values will be assigned into [foo.bar], not [foo]
|
|
for(const auto& kv : v)
|
|
{
|
|
if(kv.second.is_table() || is_array_of_tables(kv.second))
|
|
{
|
|
continue;
|
|
}
|
|
|
|
if(!kv.second.comments().empty() && !no_comment_)
|
|
{
|
|
for(const auto& c : kv.second.comments())
|
|
{
|
|
token += '#';
|
|
token += c;
|
|
token += '\n';
|
|
}
|
|
}
|
|
const auto key_and_sep = this->serialize_key(kv.first) + " = ";
|
|
const auto residual_width = (this->width_ > key_and_sep.size()) ?
|
|
this->width_ - key_and_sep.size() : 0;
|
|
token += key_and_sep;
|
|
token += visit(serializer(residual_width, this->float_prec_, true),
|
|
kv.second);
|
|
if(token.back() != '\n')
|
|
{
|
|
token += '\n';
|
|
}
|
|
}
|
|
|
|
// normal tables / array of tables
|
|
|
|
// after multiline table appeared, the other tables cannot be inline
|
|
// because the table would be assigned into the table.
|
|
// [foo]
|
|
// ...
|
|
// bar = {...} # <- bar will be a member of [foo].
|
|
bool multiline_table_printed = false;
|
|
for(const auto& kv : v)
|
|
{
|
|
if(!kv.second.is_table() && !is_array_of_tables(kv.second))
|
|
{
|
|
continue; // other stuff are already serialized. skip them.
|
|
}
|
|
|
|
std::vector<toml::key> ks(this->keys_);
|
|
ks.push_back(kv.first);
|
|
|
|
auto tmp = visit(serializer(this->width_, this->float_prec_,
|
|
!multiline_table_printed, this->no_comment_, ks),
|
|
kv.second);
|
|
|
|
if((!multiline_table_printed) &&
|
|
std::find(tmp.cbegin(), tmp.cend(), '\n') != tmp.cend())
|
|
{
|
|
multiline_table_printed = true;
|
|
}
|
|
else
|
|
{
|
|
// still inline tables only.
|
|
tmp += '\n';
|
|
}
|
|
|
|
if(!kv.second.comments().empty() && !no_comment_)
|
|
{
|
|
for(const auto& c : kv.second.comments())
|
|
{
|
|
token += '#';
|
|
token += c;
|
|
token += '\n';
|
|
}
|
|
}
|
|
token += tmp;
|
|
}
|
|
return token;
|
|
}
|
|
|
|
bool is_array_of_tables(const value_type& v) const
|
|
{
|
|
if(!v.is_array()) {return false;}
|
|
const auto& a = v.as_array();
|
|
return !a.empty() && a.front().is_table();
|
|
}
|
|
|
|
private:
|
|
|
|
bool can_be_inlined_;
|
|
bool no_comment_;
|
|
int float_prec_;
|
|
std::size_t width_;
|
|
std::vector<toml::key> keys_;
|
|
};
|
|
|
|
template<typename C,
|
|
template<typename ...> class M, template<typename ...> class V>
|
|
std::string
|
|
format(const basic_value<C, M, V>& v, std::size_t w = 80u,
|
|
int fprec = std::numeric_limits<toml::floating>::max_digits10,
|
|
bool no_comment = false, bool force_inline = false)
|
|
{
|
|
// if value is a table, it is considered to be a root object.
|
|
// the root object can't be an inline table.
|
|
if(v.is_table())
|
|
{
|
|
std::ostringstream oss;
|
|
if(!v.comments().empty())
|
|
{
|
|
oss << v.comments();
|
|
oss << '\n'; // to split the file comment from the first element
|
|
}
|
|
oss << visit(serializer<C, M, V>(w, fprec, no_comment, false), v);
|
|
return oss.str();
|
|
}
|
|
return visit(serializer<C, M, V>(w, fprec, force_inline), v);
|
|
}
|
|
|
|
namespace detail
|
|
{
|
|
template<typename charT, typename traits>
|
|
int comment_index(std::basic_ostream<charT, traits>&)
|
|
{
|
|
static const int index = std::ios_base::xalloc();
|
|
return index;
|
|
}
|
|
} // detail
|
|
|
|
template<typename charT, typename traits>
|
|
std::basic_ostream<charT, traits>&
|
|
nocomment(std::basic_ostream<charT, traits>& os)
|
|
{
|
|
// by default, it is zero. and by defalut, it shows comments.
|
|
os.iword(detail::comment_index(os)) = 1;
|
|
return os;
|
|
}
|
|
|
|
template<typename charT, typename traits>
|
|
std::basic_ostream<charT, traits>&
|
|
showcomment(std::basic_ostream<charT, traits>& os)
|
|
{
|
|
// by default, it is zero. and by defalut, it shows comments.
|
|
os.iword(detail::comment_index(os)) = 0;
|
|
return os;
|
|
}
|
|
|
|
template<typename charT, typename traits, typename C,
|
|
template<typename ...> class M, template<typename ...> class V>
|
|
std::basic_ostream<charT, traits>&
|
|
operator<<(std::basic_ostream<charT, traits>& os, const basic_value<C, M, V>& v)
|
|
{
|
|
// get status of std::setw().
|
|
const auto w = static_cast<std::size_t>(os.width());
|
|
const int fprec = static_cast<int>(os.precision());
|
|
os.width(0);
|
|
|
|
// by defualt, iword is initialized byl 0. And by default, toml11 outputs
|
|
// comments. So `0` means showcomment. 1 means nocommnet.
|
|
const bool no_comment = (1 == os.iword(detail::comment_index(os)));
|
|
|
|
if(!no_comment && v.is_table() && !v.comments().empty())
|
|
{
|
|
os << v.comments();
|
|
os << '\n'; // to split the file comment from the first element
|
|
}
|
|
// the root object can't be an inline table. so pass `false`.
|
|
os << visit(serializer<C, M, V>(w, fprec, false, no_comment), v);
|
|
|
|
// if v is a non-table value, and has only one comment, then
|
|
// put a comment just after a value. in the following way.
|
|
//
|
|
// ```toml
|
|
// key = "value" # comment.
|
|
// ```
|
|
//
|
|
// Since the top-level toml object is a table, one who want to put a
|
|
// non-table toml value must use this in a following way.
|
|
//
|
|
// ```cpp
|
|
// toml::value v;
|
|
// std::cout << "user-defined-key = " << v << std::endl;
|
|
// ```
|
|
//
|
|
// In this case, it is impossible to put comments before key-value pair.
|
|
// The only way to preserve comments is to put all of them after a value.
|
|
if(!no_comment && !v.is_table() && !v.comments().empty())
|
|
{
|
|
os << " #";
|
|
for(const auto& c : v.comments()) {os << c;}
|
|
}
|
|
return os;
|
|
}
|
|
|
|
} // toml
|
|
#endif// TOML11_SERIALIZER_HPP
|