const_fmt/inc/format.h

81 lines
2.1 KiB
C++

#ifndef LOGGER_FORMAT_H
#define LOGGER_FORMAT_H
#include "parse.h"
namespace detail {
template <ConstString s>
constexpr int get_output_len() {
constexpr auto parse_result = parse_string<s>();
static_assert(parse_result.is_valid, "Syntax error in log string");
unsigned result = 0;
for (const auto& ast_node : parse_result.value) {
if (ast_node.is_char())
++result;
else
result += ast_node.get_node().length;
}
return result;
}
template <typename T, fmt_node_t fmt_node>
constexpr bool is_valid_type() {
// TODO
return true;
}
template <fmt_node_t fmt_node, typename T>
constexpr std::array<char, fmt_node.length> format_arg(T arg) {
static_assert(is_valid_type<T, fmt_node>(), "Invalid argument type");
std::array<char, fmt_node.length> result;
for (auto& c : result)
c = 'f';
return result;
}
template<auto t_ast, unsigned t_ast_i=0, unsigned t_result_i=0, typename char_array_t, typename first_arg_t, typename... other_args_t>
constexpr char_array_t format_args(char_array_t result, first_arg_t first_arg, other_args_t... other_args) {
if constexpr(t_ast_i >= t_ast.size()) {
return result;
} else {
if (t_ast[t_ast_i].is_char()) {
result[t_result_i] = t_ast[t_ast_i].get_char();
return format_args<t_ast, t_ast_i+1, t_result_i+1>(result, first_arg, other_args...);
} else {
const auto formatted_arg = format_arg<t_ast[t_ast_i].get_node()>(first_arg);
std::copy(formatted_arg.begin(), formatted_arg.end(), result.begin()+t_result_i);
return format_args<t_ast, t_ast_i+1, t_result_i+t_ast[t_ast_i].get_node().length>(result, first_arg, other_args...);
}
}
}
} // namespace detail
template <detail::ConstString s, typename... args_t>
std::array<char, detail::get_output_len<s>()> format(args_t... args) {
constexpr auto parse_result = detail::parse_string<s>();
static_assert(parse_result.is_valid);
std::array<char, detail::get_output_len<s>()> result;
return detail::format_args<parse_result.value>(result, args...);
}
#endif // LOGGER_FORMAT_H