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Diffstat (limited to 'src/toml11/toml/region.hpp')
| -rw-r--r-- | src/toml11/toml/region.hpp | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/src/toml11/toml/region.hpp b/src/toml11/toml/region.hpp new file mode 100644 index 000000000..2e01e51d0 --- /dev/null +++ b/src/toml11/toml/region.hpp @@ -0,0 +1,417 @@ +// Copyright Toru Niina 2017. +// Distributed under the MIT License. +#ifndef TOML11_REGION_HPP +#define TOML11_REGION_HPP +#include <memory> +#include <vector> +#include <algorithm> +#include <initializer_list> +#include <iterator> +#include <iomanip> +#include <cassert> +#include "color.hpp" + +namespace toml +{ +namespace detail +{ + +// helper function to avoid std::string(0, 'c') or std::string(iter, iter) +template<typename Iterator> +std::string make_string(Iterator first, Iterator last) +{ + if(first == last) {return "";} + return std::string(first, last); +} +inline std::string make_string(std::size_t len, char c) +{ + if(len == 0) {return "";} + return std::string(len, c); +} + +// region_base is a base class of location and region that are defined below. +// it will be used to generate better error messages. +struct region_base +{ + region_base() = default; + virtual ~region_base() = default; + region_base(const region_base&) = default; + region_base(region_base&& ) = default; + region_base& operator=(const region_base&) = default; + region_base& operator=(region_base&& ) = default; + + virtual bool is_ok() const noexcept {return false;} + virtual char front() const noexcept {return '\0';} + + virtual std::string str() const {return std::string("unknown region");} + virtual std::string name() const {return std::string("unknown file");} + virtual std::string line() const {return std::string("unknown line");} + virtual std::string line_num() const {return std::string("?");} + + // length of the region + virtual std::size_t size() const noexcept {return 0;} + // number of characters in the line before the region + virtual std::size_t before() const noexcept {return 0;} + // number of characters in the line after the region + virtual std::size_t after() const noexcept {return 0;} + + virtual std::vector<std::string> comments() const {return {};} + // ```toml + // # comment_before + // key = "value" # comment_inline + // ``` +}; + +// location represents a position in a container, which contains a file content. +// it can be considered as a region that contains only one character. +// +// it contains pointer to the file content and iterator that points the current +// location. +struct location final : public region_base +{ + using const_iterator = typename std::vector<char>::const_iterator; + using difference_type = typename const_iterator::difference_type; + using source_ptr = std::shared_ptr<const std::vector<char>>; + + location(std::string source_name, std::vector<char> cont) + : source_(std::make_shared<std::vector<char>>(std::move(cont))), + line_number_(1), source_name_(std::move(source_name)), iter_(source_->cbegin()) + {} + location(std::string source_name, const std::string& cont) + : source_(std::make_shared<std::vector<char>>(cont.begin(), cont.end())), + line_number_(1), source_name_(std::move(source_name)), iter_(source_->cbegin()) + {} + + location(const location&) = default; + location(location&&) = default; + location& operator=(const location&) = default; + location& operator=(location&&) = default; + ~location() = default; + + bool is_ok() const noexcept override {return static_cast<bool>(source_);} + char front() const noexcept override {return *iter_;} + + // this const prohibits codes like `++(loc.iter())`. + const const_iterator iter() const noexcept {return iter_;} + + const_iterator begin() const noexcept {return source_->cbegin();} + const_iterator end() const noexcept {return source_->cend();} + + // XXX `location::line_num()` used to be implemented using `std::count` to + // count a number of '\n'. But with a long toml file (typically, 10k lines), + // it becomes intolerably slow because each time it generates error messages, + // it counts '\n' from thousands of characters. To workaround it, I decided + // to introduce `location::line_number_` member variable and synchronize it + // to the location changes the point to look. So an overload of `iter()` + // which returns mutable reference is removed and `advance()`, `retrace()` + // and `reset()` is added. + void advance(difference_type n = 1) noexcept + { + this->line_number_ += static_cast<std::size_t>( + std::count(this->iter_, std::next(this->iter_, n), '\n')); + this->iter_ += n; + return; + } + void retrace(difference_type n = 1) noexcept + { + this->line_number_ -= static_cast<std::size_t>( + std::count(std::prev(this->iter_, n), this->iter_, '\n')); + this->iter_ -= n; + return; + } + void reset(const_iterator rollback) noexcept + { + // since c++11, std::distance works in both ways for random-access + // iterators and returns a negative value if `first > last`. + if(0 <= std::distance(rollback, this->iter_)) // rollback < iter + { + this->line_number_ -= static_cast<std::size_t>( + std::count(rollback, this->iter_, '\n')); + } + else // iter < rollback [[unlikely]] + { + this->line_number_ += static_cast<std::size_t>( + std::count(this->iter_, rollback, '\n')); + } + this->iter_ = rollback; + return; + } + + std::string str() const override {return make_string(1, *this->iter());} + std::string name() const override {return source_name_;} + + std::string line_num() const override + { + return std::to_string(this->line_number_); + } + + std::string line() const override + { + return make_string(this->line_begin(), this->line_end()); + } + + const_iterator line_begin() const noexcept + { + using reverse_iterator = std::reverse_iterator<const_iterator>; + return std::find(reverse_iterator(this->iter()), + reverse_iterator(this->begin()), '\n').base(); + } + const_iterator line_end() const noexcept + { + return std::find(this->iter(), this->end(), '\n'); + } + + // location is always points a character. so the size is 1. + std::size_t size() const noexcept override + { + return 1u; + } + std::size_t before() const noexcept override + { + const auto sz = std::distance(this->line_begin(), this->iter()); + assert(sz >= 0); + return static_cast<std::size_t>(sz); + } + std::size_t after() const noexcept override + { + const auto sz = std::distance(this->iter(), this->line_end()); + assert(sz >= 0); + return static_cast<std::size_t>(sz); + } + + source_ptr const& source() const& noexcept {return source_;} + source_ptr&& source() && noexcept {return std::move(source_);} + + private: + + source_ptr source_; + std::size_t line_number_; + std::string source_name_; + const_iterator iter_; +}; + +// region represents a range in a container, which contains a file content. +// +// it contains pointer to the file content and iterator that points the first +// and last location. +struct region final : public region_base +{ + using const_iterator = typename std::vector<char>::const_iterator; + using source_ptr = std::shared_ptr<const std::vector<char>>; + + // delete default constructor. source_ never be null. + region() = delete; + + explicit region(const location& loc) + : source_(loc.source()), source_name_(loc.name()), + first_(loc.iter()), last_(loc.iter()) + {} + explicit region(location&& loc) + : source_(loc.source()), source_name_(loc.name()), + first_(loc.iter()), last_(loc.iter()) + {} + + region(const location& loc, const_iterator f, const_iterator l) + : source_(loc.source()), source_name_(loc.name()), first_(f), last_(l) + {} + region(location&& loc, const_iterator f, const_iterator l) + : source_(loc.source()), source_name_(loc.name()), first_(f), last_(l) + {} + + region(const region&) = default; + region(region&&) = default; + region& operator=(const region&) = default; + region& operator=(region&&) = default; + ~region() = default; + + region& operator+=(const region& other) + { + // different regions cannot be concatenated + assert(this->begin() == other.begin() && this->end() == other.end() && + this->last_ == other.first_); + + this->last_ = other.last_; + return *this; + } + + bool is_ok() const noexcept override {return static_cast<bool>(source_);} + char front() const noexcept override {return *first_;} + + std::string str() const override {return make_string(first_, last_);} + std::string line() const override + { + if(this->contain_newline()) + { + return make_string(this->line_begin(), + std::find(this->line_begin(), this->last(), '\n')); + } + return make_string(this->line_begin(), this->line_end()); + } + std::string line_num() const override + { + return std::to_string(1 + std::count(this->begin(), this->first(), '\n')); + } + + std::size_t size() const noexcept override + { + const auto sz = std::distance(first_, last_); + assert(sz >= 0); + return static_cast<std::size_t>(sz); + } + std::size_t before() const noexcept override + { + const auto sz = std::distance(this->line_begin(), this->first()); + assert(sz >= 0); + return static_cast<std::size_t>(sz); + } + std::size_t after() const noexcept override + { + const auto sz = std::distance(this->last(), this->line_end()); + assert(sz >= 0); + return static_cast<std::size_t>(sz); + } + + bool contain_newline() const noexcept + { + return std::find(this->first(), this->last(), '\n') != this->last(); + } + + const_iterator line_begin() const noexcept + { + using reverse_iterator = std::reverse_iterator<const_iterator>; + return std::find(reverse_iterator(this->first()), + reverse_iterator(this->begin()), '\n').base(); + } + const_iterator line_end() const noexcept + { + return std::find(this->last(), this->end(), '\n'); + } + + const_iterator begin() const noexcept {return source_->cbegin();} + const_iterator end() const noexcept {return source_->cend();} + const_iterator first() const noexcept {return first_;} + const_iterator last() const noexcept {return last_;} + + source_ptr const& source() const& noexcept {return source_;} + source_ptr&& source() && noexcept {return std::move(source_);} + + std::string name() const override {return source_name_;} + + std::vector<std::string> comments() const override + { + // assuming the current region (`*this`) points a value. + // ```toml + // a = "value" + // ^^^^^^^- this region + // ``` + using rev_iter = std::reverse_iterator<const_iterator>; + + std::vector<std::string> com{}; + { + // find comments just before the current region. + // ```toml + // # this should be collected. + // # this also. + // a = value # not this. + // ``` + + // # this is a comment for `a`, not array elements. + // a = [1, 2, 3, 4, 5] + if(this->first() == std::find_if(this->line_begin(), this->first(), + [](const char c) noexcept -> bool {return c == '[' || c == '{';})) + { + auto iter = this->line_begin(); // points the first character + while(iter != this->begin()) + { + iter = std::prev(iter); + + // range [line_start, iter) represents the previous line + const auto line_start = std::find( + rev_iter(iter), rev_iter(this->begin()), '\n').base(); + const auto comment_found = std::find(line_start, iter, '#'); + if(comment_found == iter) + { + break; // comment not found. + } + + // exclude the following case. + // > a = "foo" # comment // <-- this is not a comment for b but a. + // > b = "current value" + if(std::all_of(line_start, comment_found, + [](const char c) noexcept -> bool { + return c == ' ' || c == '\t'; + })) + { + // unwrap the first '#' by std::next. + auto s = make_string(std::next(comment_found), iter); + if(!s.empty() && s.back() == '\r') {s.pop_back();} + com.push_back(std::move(s)); + } + else + { + break; + } + iter = line_start; + } + } + } + + if(com.size() > 1) + { + std::reverse(com.begin(), com.end()); + } + + { + // find comments just after the current region. + // ```toml + // # not this. + // a = value # this one. + // a = [ # not this (technically difficult) + // + // ] # and this. + // ``` + // The reason why it's difficult is that it requires parsing in the + // following case. + // ```toml + // a = [ 10 # this comment is for `10`. not for `a` but `a[0]`. + // # ... + // ] # this is apparently a comment for a. + // + // b = [ + // 3.14 ] # there is no way to add a comment to `3.14` currently. + // + // c = [ + // 3.14 # do this if you need a comment here. + // ] + // ``` + const auto comment_found = + std::find(this->last(), this->line_end(), '#'); + if(comment_found != this->line_end()) // '#' found + { + // table = {key = "value"} # what is this for? + // the above comment is not for "value", but {key="value"}. + if(comment_found == std::find_if(this->last(), comment_found, + [](const char c) noexcept -> bool { + return !(c == ' ' || c == '\t' || c == ','); + })) + { + // unwrap the first '#' by std::next. + auto s = make_string(std::next(comment_found), this->line_end()); + if(!s.empty() && s.back() == '\r') {s.pop_back();} + com.push_back(std::move(s)); + } + } + } + return com; + } + + private: + + source_ptr source_; + std::string source_name_; + const_iterator first_, last_; +}; + +} // detail +} // toml +#endif// TOML11_REGION_H |