Echo Writes Code

bits.inl

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#ifndef CRUCIBLE_PARSING_BITS_INL
#define CRUCIBLE_PARSING_BITS_INL

#include "crucible/parsing/bits.hpp"

#include <climits>

namespace crucible::parsing::bits {
  template<FixedWidthUnsignedIntegerType T>
  auto LittleEndianUnsignedInteger<T>::operator()(StateType const &state) const -> ResultType {
    auto const remaining_bytes = state.get_remaining_bytes_in_input();

    if (remaining_bytes.size() < sizeof(T)) {
      return result::reject(state, BitsError { UnexpectedEndOfInput {} });
    }

    T total = 0;

    for (std::size_t i = 0; i < sizeof(T); ++i) {
      std::size_t const bits_to_shift = i * CHAR_BIT;
      auto const byte_value = std::to_integer<T>(remaining_bytes[i]);
      T const shifted_value = byte_value << bits_to_shift;
      total |= shifted_value;
    }

    auto const next_state = state.advance_by_bytes(sizeof(T));
    return result::accept(next_state, total);
  }

  template<FixedWidthUnsignedIntegerType T>
  auto BigEndianUnsignedInteger<T>::operator()(StateType const &state) const -> ResultType {
    auto const remaining_bytes = state.get_remaining_bytes_in_input();

    if (remaining_bytes.size() < sizeof(T)) {
      return result::reject(state, BitsError { UnexpectedEndOfInput {} });
    }

    T total = 0;

    for (std::size_t i = 0; i < sizeof(T); ++i) {
      std::size_t const bits_to_shift = (sizeof(T) - (i + 1)) * CHAR_BIT;
      auto const byte_value = std::to_integer<T>(remaining_bytes[i]);
      T const shifted_value = byte_value << bits_to_shift;
      total |= shifted_value;
    }

    auto const next_state = state.advance_by_bytes(sizeof(T));
    return result::accept(next_state, total);
  }
}

#endif // CRUCIBLE_PARSING_BITS_INL