base_views.hpp

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// SPDX-FileCopyrightText: 2026 Jarosław Pelczar <jarek@jpelczar.com>
//
// SPDX-License-Identifier: BSD-2-Clause
 
#pragma once
 
#include "binary.hpp"
#include <cstddef>
#include <cstdint>
#include <string_view>
#include <type_traits>
 
namespace microfmt {
 
// ============================================================================
// Base64 Stream View
// ============================================================================
 
struct MICROFMT_API_CLASS RELOCO_POINTER base64_view {
  span<const uint8_t> data;
};
 
[[nodiscard]] constexpr base64_view base64(span<const uint8_t> bytes) noexcept { return base64_view{bytes}; }
 
template <size_t N> [[nodiscard]] constexpr base64_view base64(const uint8_t (&arr)[N]) noexcept {
  return base64_view{span<const uint8_t>(arr, N)};
}
 
template <> struct formatter<base64_view> {
  constexpr void parse(format_parse_context &) noexcept {}
 
  MICROFMT_API void format(const base64_view &bv, const sink &out) const noexcept;
};
 
// ============================================================================
// Grouped Binary / Radix View
// ============================================================================
 
template <typename T, typename = std::enable_if_t<std::is_integral_v<T> && !std::is_same_v<T, bool>>>
struct bin_grouped_view {
  T value;
  uint8_t group_size{4};
  char separator{'_'};
};
 
template <typename T, std::enable_if_t<std::is_integral_v<T> && !std::is_same_v<T, bool>, int> = 0>
[[nodiscard]] constexpr auto bin_grouped(T val, uint8_t group, char sep = '_') noexcept {
  return bin_grouped_view<T>{val, group, sep};
}
 
template <typename T> struct formatter<bin_grouped_view<T>> {
  constexpr void parse(format_parse_context &) noexcept {}
 
  void format(const bin_grouped_view<T> &bg, const sink &out) const noexcept {
    using UnsignedT = std::make_unsigned_t<T>;
    constexpr size_t total_bits = sizeof(T) * 8;
    const auto raw = static_cast<UnsignedT>(bg.value);
 
    out.write("0b");
    for (size_t i = 0; i < total_bits; ++i) {
      const size_t bit_idx = total_bits - 1 - i;
      out.put((raw & (UnsignedT{1} << bit_idx)) ? '1' : '0');
 
      if (bg.group_size != 0 && (i + 1) < total_bits && (bit_idx % bg.group_size == 0)) {
        out.put(bg.separator);
      }
    }
  }
};
 
} // namespace microfmt
 
#if MICROFMT_SHARED_PROVIDE_DEFINITIONS
#include "base_views.ipp"
#endif