toml11/toml/region.hpp
2018-12-12 23:22:31 +09:00

302 lines
9.3 KiB
C++

#ifndef TOML11_REGION_H
#define TOML11_REGION_H
#include "exception.hpp"
#include <memory>
#include <vector>
#include <algorithm>
#include <initializer_list>
#include <iterator>
#include <iostream>
namespace toml
{
namespace detail
{
// helper function to avoid std::string(0, 'c')
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);
}
// location in a container, normally in a file content.
// shared_ptr points the resource that the iter points.
// it can be used not only for resource handling, but also error message.
template<typename Container>
struct location
{
static_assert(std::is_same<char, typename Container::value_type>::value,"");
using const_iterator = typename Container::const_iterator;
using source_ptr = std::shared_ptr<const Container>;
location(std::string name, Container cont)
: source_(std::make_shared<Container>(std::move(cont))),
source_name_(std::move(name)), iter_(source_->cbegin())
{}
location(const location&) = default;
location(location&&) = default;
location& operator=(const location&) = default;
location& operator=(location&&) = default;
~location() = default;
const_iterator& iter() noexcept {return iter_;}
const_iterator iter() const noexcept {return iter_;}
const_iterator begin() const noexcept {return source_->cbegin();}
const_iterator end() const noexcept {return source_->cend();}
source_ptr const& source() const& noexcept {return source_;}
source_ptr&& source() && noexcept {return std::move(source_);}
std::string const& name() const noexcept {return source_name_;}
private:
source_ptr source_;
std::string source_name_;
const_iterator iter_;
};
// region in a container, normally in a file content.
// shared_ptr points the resource that the iter points.
// combinators returns this.
// 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 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("?");}
virtual std::size_t before() const noexcept {return 0;}
virtual std::size_t size() const noexcept {return 0;}
virtual std::size_t after() const noexcept {return 0;}
};
template<typename Container>
struct region final : public region_base
{
static_assert(std::is_same<char, typename Container::value_type>::value,"");
using const_iterator = typename Container::const_iterator;
using source_ptr = std::shared_ptr<const Container>;
// delete default constructor. source_ never be null.
region() = delete;
region(const location<Container>& loc)
: source_(loc.source()), source_name_(loc.name()),
first_(loc.iter()), last_(loc.iter())
{}
region(location<Container>&& loc)
: source_(loc.source()), source_name_(loc.name()),
first_(loc.iter()), last_(loc.iter())
{}
region(const location<Container>& loc, const_iterator f, const_iterator l)
: source_(loc.source()), source_name_(loc.name()), first_(f), last_(l)
{}
region(location<Container>&& 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)
{
if(this->begin() != other.begin() || this->end() != other.end() ||
this->last_ != other.first_)
{
throw internal_error("invalid region concatenation");
}
this->last_ = other.last_;
return *this;
}
bool is_ok() const noexcept override {return static_cast<bool>(source_);}
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
{
return std::distance(first_, last_);
}
std::size_t before() const noexcept override
{
return std::distance(this->line_begin(), this->first());
}
std::size_t after() const noexcept override
{
return std::distance(this->last(), this->line_end());
}
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_;}
private:
source_ptr source_;
std::string source_name_;
const_iterator first_, last_;
};
// to show a better error message.
inline std::string format_underline(const std::string& message,
const region_base& reg, const std::string& comment_for_underline,
std::vector<std::string> helps = {})
{
#ifdef _WIN32
const auto newline = "\r\n";
#else
const char newline = '\n';
#endif
const auto line = reg.line();
const auto line_number = reg.line_num();
std::string retval;
retval += message;
retval += newline;
retval += " --> ";
retval += reg.name();
retval += newline;
retval += ' ';
retval += line_number;
retval += " | ";
retval += line;
retval += newline;
retval += make_string(line_number.size() + 1, ' ');
retval += " | ";
retval += make_string(reg.before(), ' ');
retval += make_string(reg.size(), '~');
retval += ' ';
retval += comment_for_underline;
if(helps.size() != 0)
{
retval += newline;
retval += make_string(line_number.size() + 1, ' ');
retval += " | ";
for(const auto help : helps)
{
retval += newline;
retval += "Hint: ";
retval += help;
}
}
return retval;
}
// to show a better error message.
template<typename Container>
std::string
format_underline(const std::string& message, const location<Container>& loc,
const std::string& comment_for_underline,
std::vector<std::string> helps = {})
{
#ifdef _WIN32
const auto newline = "\r\n";
#else
const char newline = '\n';
#endif
using const_iterator = typename location<Container>::const_iterator;
using reverse_iterator = std::reverse_iterator<const_iterator>;
const auto line_begin = std::find(reverse_iterator(loc.iter()),
reverse_iterator(loc.begin()),
'\n').base();
const auto line_end = std::find(loc.iter(), loc.end(), '\n');
const auto line_number = std::to_string(
1 + std::count(loc.begin(), loc.iter(), '\n'));
std::string retval;
retval += message;
retval += newline;
retval += " --> ";
retval += loc.name();
retval += newline;
retval += ' ';
retval += line_number;
retval += " | ";
retval += make_string(line_begin, line_end);
retval += newline;
retval += make_string(line_number.size() + 1, ' ');
retval += " | ";
retval += make_string(std::distance(line_begin, loc.iter()),' ');
retval += '^';
retval += make_string(std::distance(loc.iter(), line_end), '-');
retval += ' ';
retval += comment_for_underline;
if(helps.size() != 0)
{
retval += newline;
retval += make_string(line_number.size() + 1, ' ');
retval += " | ";
for(const auto help : helps)
{
retval += newline;
retval += "Hint: ";
retval += help;
}
}
return retval;
}
} // detail
} // toml
#endif// TOML11_REGION_H