tomlplusplus/include/toml++/toml_default_formatter.h
Mark Gillard 41d05792a5 narrowed scope of abi namespacing
also
- simplified `noexcept` specifiers (removed `TOML_MAY_THROW_UNLESS`)
- minor documentation fixes
2020-03-28 18:56:59 +02:00

531 lines
14 KiB
C++

//# This file is a part of toml++ and is subject to the the terms of the MIT license.
//# Copyright (c) 2019-2020 Mark Gillard <mark.gillard@outlook.com.au>
//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.
#pragma once
#include "toml_formatter.h"
#include "toml_table.h"
#include "toml_array.h"
#include "toml_utf8.h"
namespace toml::impl
{
TOML_PUSH_WARNINGS
TOML_DISABLE_ALL_WARNINGS
[[nodiscard]]
inline toml::string default_formatter_make_key_segment(const toml::string& str) noexcept
{
if (str.empty())
return TOML_STRING_PREFIX("''"s);
else
{
bool requiresQuotes = false;
{
impl::utf8_decoder decoder;
for (size_t i = 0; i < str.length() && !requiresQuotes; i++)
{
decoder(static_cast<uint8_t>(str[i]));
if (decoder.error())
requiresQuotes = true;
else if (decoder.has_code_point())
requiresQuotes = !impl::is_bare_key_character(decoder.codepoint);
}
}
if (requiresQuotes)
{
toml::string s;
s.reserve(str.length() + 2_sz);
s += TOML_STRING_PREFIX('"');
for (auto c : str)
{
if (c >= TOML_STRING_PREFIX('\x00') && c <= TOML_STRING_PREFIX('\x1F')) TOML_UNLIKELY
s.append(low_character_escape_table[c]);
else if (c == TOML_STRING_PREFIX('\x7F')) TOML_UNLIKELY
s.append(TOML_STRING_PREFIX("\\u007F"sv));
else if (c == TOML_STRING_PREFIX('"')) TOML_UNLIKELY
s.append(TOML_STRING_PREFIX("\\\""sv));
else
s += c;
}
s += TOML_STRING_PREFIX('"');
return s;
}
else
return str;
}
}
TOML_POP_WARNINGS
[[nodiscard]]
inline size_t default_formatter_inline_columns(const node& node) noexcept
{
return node.visit([](const auto& n) noexcept
-> size_t
{
if constexpr (is_table<decltype(n)>)
{
if (n.empty())
return 2_sz; // "{}"
size_t weight = 3_sz; // "{ }"
for (auto [k, v] : n)
weight += k.length() + default_formatter_inline_columns(v) + 2_sz; // + ", "
return weight;
}
else if constexpr (is_array<decltype(n)>)
{
if (n.empty())
return 2_sz; // "[]"
size_t weight = 3_sz; // "[ ]"
for (auto& elem : n)
weight += default_formatter_inline_columns(elem) + 2_sz; // + ", "
return weight;
}
else if constexpr (is_string<decltype(n)>)
{
return n.get().length() + 2_sz; // + ""
}
else if constexpr (is_number<decltype(n)>)
{
static constexpr auto digit_count = [](auto num) noexcept
-> size_t
{
using number_t = decltype(num);
size_t digits = 1_sz;
while (num >= number_t{ 10 })
{
num /= number_t{ 10 };
digits++;
}
return digits;
};
if constexpr (is_integer<decltype(n)>)
{
auto v = n.get();
if (!v)
return 1_sz;
size_t weight = {};
if (v < 0)
{
weight += 1;
v *= -1;
}
return weight + digit_count(v);
}
else if constexpr (is_floating_point<decltype(n)>)
{
auto v = n.get();
if (v == 0.0)
return 3_sz;
size_t weight = 2_sz; // ".0"
if (v < 0.0)
{
weight += 1;
v *= -1.0;
}
return weight + digit_count(v);
}
}
else if constexpr (is_boolean<decltype(n)>)
{
return 5_sz;
}
else if constexpr (is_date<decltype(n)> || is_time<decltype(n)>)
{
return 10_sz;
}
else if constexpr (is_date_time<decltype(n)>)
{
return 30_sz;
}
TOML_UNREACHABLE;
});
}
[[nodiscard]]
inline bool default_formatter_forces_multiline(const node& node, size_t starting_column_bias = 0) noexcept
{
return (default_formatter_inline_columns(node) + starting_column_bias) > 120_sz;
}
}
namespace toml
{
template <typename T, typename U>
std::basic_ostream<T>& operator << (std::basic_ostream<T>&, default_formatter<U>&);
template <typename T, typename U>
std::basic_ostream<T>& operator << (std::basic_ostream<T>&, default_formatter<U>&&);
/// \brief A wrapper for printing TOML objects out to a stream as formatted TOML.
///
/// \remarks You generally don't need to create an instance of this class explicitly; the stream
/// operators of the TOML node types already print themselves out using this formatter.
///
/// \detail \cpp
/// auto tbl = toml::table{{
/// { "description", "This is some TOML, yo." },
/// { "fruit", toml::array{ "apple", "orange", "pear" } },
/// { "numbers", toml::array{ 1, 2, 3, 4, 5 } },
/// { "table", toml::table{{ { "foo", "bar" } }} }
/// }};
///
/// // these two lines are equivalent:
/// std::cout << toml::default_formatter{ tbl } << std::endl;
/// std::cout << tbl << std::endl;
///
/// \ecpp
///
/// \out
/// description = "This is some TOML, yo."
/// fruit = ["apple", "orange", "pear"]
/// numbers = [1, 2, 3, 4, 5]
///
/// [table]
/// foo = "bar"
/// \eout
///
/// \tparam CHAR The underlying character type of the output stream. Must be 1 byte in size.
template <typename CHAR = char>
class default_formatter final : impl::formatter<CHAR>
{
private:
using base = impl::formatter<CHAR>;
std::vector<toml::string> key_path;
void print_key_segment(const toml::string& str)
{
if (str.empty())
impl::print_to_stream("''"sv, base::stream());
else
{
bool requiresQuotes = false;
{
impl::utf8_decoder decoder;
for (size_t i = 0; i < str.length() && !requiresQuotes; i++)
{
decoder(static_cast<uint8_t>(str[i]));
if (decoder.error())
requiresQuotes = true;
else if (decoder.has_code_point())
requiresQuotes = !impl::is_bare_key_character(decoder.codepoint);
}
}
if (requiresQuotes)
base::print_quoted_string(str);
else
impl::print_to_stream(str, base::stream());
}
base::clear_naked_newline();
}
void print_key_path()
{
for (const auto& segment : key_path)
{
if (std::addressof(segment) > key_path.data())
impl::print_to_stream('.', base::stream());
impl::print_to_stream(segment, base::stream());
}
base::clear_naked_newline();
}
inline void print_inline(const table& /*tbl*/);
void print(const array& arr)
{
if (arr.empty())
impl::print_to_stream("[]"sv, base::stream());
else
{
const auto original_indent = base::indent();
const auto multiline = impl::default_formatter_forces_multiline(
arr,
base::indent_columns * static_cast<size_t>(original_indent < 0 ? 0 : original_indent)
);
impl::print_to_stream("["sv, base::stream());
if (multiline)
{
if (original_indent < 0)
base::indent(0);
base::increase_indent();
}
else
impl::print_to_stream(' ', base::stream());
for (size_t i = 0; i < arr.size(); i++)
{
if (i > 0_sz)
{
impl::print_to_stream(',', base::stream());
if (!multiline)
impl::print_to_stream(' ', base::stream());
}
if (multiline)
{
base::print_newline(true);
base::print_indent();
}
auto& v = arr[i];
const auto type = v.type();
switch (type)
{
case node_type::table: print_inline(*reinterpret_cast<const table*>(&v)); break;
case node_type::array: print(*reinterpret_cast<const array*>(&v)); break;
default:
base::print(v, type);
}
}
if (multiline)
{
base::indent(original_indent);
base::print_newline(true);
base::print_indent();
}
else
impl::print_to_stream(' ', base::stream());
impl::print_to_stream("]"sv, base::stream());
}
base::clear_naked_newline();
}
void print(const table& tbl)
{
static constexpr auto is_non_inline_array_of_tables = [](auto&& nde) noexcept
{
auto arr = nde.as_array();
return arr
&& arr->is_array_of_tables()
&& !arr->template get_as<table>(0_sz)->is_inline();
};
//values, arrays, and inline tables/table arrays
for (auto [k, v] : tbl)
{
const auto type = v.type();
if ((type == node_type::table && !reinterpret_cast<const table*>(&v)->is_inline())
|| (type == node_type::array && is_non_inline_array_of_tables(v)))
continue;
base::print_newline();
base::print_indent();
print_key_segment(k);
impl::print_to_stream(" = "sv, base::stream());
switch (type)
{
case node_type::table: print_inline(*reinterpret_cast<const table*>(&v)); break;
case node_type::array: print(*reinterpret_cast<const array*>(&v)); break;
default:
base::print(v, type);
}
}
//non-inline tables
for (auto [k, v] : tbl)
{
const auto type = v.type();
if (type != node_type::table || reinterpret_cast<const table*>(&v)->is_inline())
continue;
auto& child_tbl = *reinterpret_cast<const table*>(&v);
//we can skip indenting and emitting the headers for tables that only contain other tables
//(so we don't over-nest)
size_t child_value_count{}; //includes inline tables and non-table arrays
size_t child_table_count{};
size_t child_table_array_count{};
for (auto [child_k, child_v] : child_tbl)
{
const auto child_type = child_v.type();
switch (child_type)
{
case node_type::table:
if (reinterpret_cast<const table*>(&child_v)->is_inline())
child_value_count++;
else
child_table_count++;
break;
case node_type::array:
if (is_non_inline_array_of_tables(child_v))
child_table_array_count++;
else
child_value_count++;
break;
default:
child_value_count++;
}
}
bool skip_self = false;
if (child_value_count == 0_sz && (child_table_count > 0_sz || child_table_array_count > 0_sz))
skip_self = true;
if (!skip_self)
base::increase_indent();
key_path.push_back(impl::default_formatter_make_key_segment(k));
if (!skip_self)
{
base::print_newline();
base::print_newline(true);
base::print_indent();
impl::print_to_stream("["sv, base::stream());
print_key_path();
impl::print_to_stream("]"sv, base::stream());
base::print_newline(true);
}
print(child_tbl);
key_path.pop_back();
if (!skip_self)
base::decrease_indent();
}
//table arrays
for (auto [k, v] : tbl)
{
if (!is_non_inline_array_of_tables(v))
continue;
auto& arr = *reinterpret_cast<const array*>(&v);
base::increase_indent();
key_path.push_back(impl::default_formatter_make_key_segment(k));
for (size_t i = 0; i < arr.size(); i++)
{
base::print_newline();
base::print_newline(true);
base::print_indent();
impl::print_to_stream("[["sv, base::stream());
print_key_path();
impl::print_to_stream("]]"sv, base::stream());
base::print_newline(true);
print(*reinterpret_cast<const table*>(&arr[i]));
}
key_path.pop_back();
base::decrease_indent();
}
}
void print()
{
switch (auto source_type = base::source().type())
{
case node_type::table:
{
auto& tbl = *reinterpret_cast<const table*>(&base::source());
if (tbl.is_inline())
print_inline(tbl);
else
{
base::decrease_indent(); // so root kvps and tables have the same indent
print(tbl);
}
break;
}
case node_type::array:
print(*reinterpret_cast<const array*>(&base::source()));
break;
default:
base::print(base::source(), source_type);
}
}
public:
/// \brief Constructs a default formatter and binds it to a TOML object.
///
/// \param source The source TOML object.
/// \param flags Format option flags.
TOML_NODISCARD_CTOR
explicit default_formatter(const toml::node& source, format_flags flags = {}) noexcept
: base{ source, flags }
{}
template <typename T, typename U>
friend std::basic_ostream<T>& operator << (std::basic_ostream<T>&, default_formatter<U>&);
template <typename T, typename U>
friend std::basic_ostream<T>& operator << (std::basic_ostream<T>&, default_formatter<U>&&);
};
default_formatter(const table&) -> default_formatter<char>;
default_formatter(const array&) -> default_formatter<char>;
template <typename T> default_formatter(const value<T>&) -> default_formatter<char>;
template <typename CHAR>
inline void default_formatter<CHAR>::print_inline(const toml::table& tbl)
{
if (tbl.empty())
impl::print_to_stream("{}"sv, base::stream());
else
{
impl::print_to_stream("{ "sv, base::stream());
bool first = false;
for (auto [k, v] : tbl)
{
if (first)
impl::print_to_stream(", "sv, base::stream());
first = true;
print_key_segment(k);
impl::print_to_stream(" = "sv, base::stream());
const auto type = v.type();
switch (type)
{
case node_type::table: print_inline(*reinterpret_cast<const table*>(&v)); break;
case node_type::array: print(*reinterpret_cast<const array*>(&v)); break;
default:
base::print(v, type);
}
}
impl::print_to_stream(" }"sv, base::stream());
}
base::clear_naked_newline();
}
/// \brief Prints the bound TOML object out to the stream as formatted TOML.
template <typename T, typename U>
inline std::basic_ostream<T>& operator << (std::basic_ostream<T>& lhs, default_formatter<U>& rhs)
{
rhs.attach(lhs);
rhs.key_path.clear();
rhs.print();
rhs.detach();
return lhs;
}
/// \brief Prints the bound TOML object out to the stream as formatted TOML (rvalue overload).
template <typename T, typename U>
inline std::basic_ostream<T>& operator << (std::basic_ostream<T>& lhs, default_formatter<U>&& rhs)
{
return lhs << rhs; //as lvalue
}
template <typename CHAR>
inline std::basic_ostream<CHAR>& operator << (std::basic_ostream<CHAR>& lhs, const table& rhs)
{
return lhs << default_formatter<CHAR>{ rhs };
}
template <typename CHAR>
inline std::basic_ostream<CHAR>& operator << (std::basic_ostream<CHAR>& lhs, const array& rhs)
{
return lhs << default_formatter<CHAR>{ rhs };
}
}