feat(furlang): add serialization

furas/include/furas/lexer.hpp

@@ -24,7 +24,7 @@ struct lexer_error {
     std::string    message;
 };
 
-using token_r = furlang::result<token, lexer_error>;
+using token_r = furlang::result<lexer_error, token>;
 
 class lexer {
 public:

furas/src/lexer.cpp

@@ -19,7 +19,7 @@ token_r lexer::next_token() {
     // TODO: Add support for single-line comments
     // TODO: Add support for multi-line comments
 
-    if (m_cursor >= m_content.size()) return token_r{ lexer_error{ lexer_error::EndOfFile, location() } };
+    if (m_cursor >= m_content.size()) return token_r::error(lexer_error{ lexer_error::EndOfFile, location() });
 
     // TODO: Add support for negative integers (I am positive thanks to stasiu :v:)
     // TODO: Add support for hexadecimal and binary numeric literals
@@ -93,9 +93,9 @@ token_r lexer::next_token() {
     case '.': ++m_cursor; return { token::Dot };
     case ':': ++m_cursor; return { token::Colon };
     default:
-        return token_r{
+        return token_r::error(lexer_error{ lexer_error::UnknownCharacter,
-            lexer_error{ lexer_error::UnknownCharacter, location(), "Unknown character '"s + m_content[m_cursor] + "'" }
+            location(),
-        };
+            "Unknown character '"s + m_content[m_cursor] + "'" });
     }
 }
 

furlang/include/furlang/serialization/codec.hpp

@@ -0,0 +1,58 @@
+#ifndef FURLANG_SERIALIZATION_CODEC_HPP
+#define FURLANG_SERIALIZATION_CODEC_HPP
+
+#include "furlang/result.hpp"
+#include "furlang/serialization/io.hpp"
+
+#include <type_traits>
+#include <utility>
+
+namespace furlang {
+namespace serialization {
+
+template <typename Codec, typename T>
+using codec_encode_result_t = decltype(std::declval<Codec>().encode(std::declval<writer&>(), std::declval<const T&>()));
+
+template <typename Codec, typename T>
+using codec_decode_result_t = decltype(std::declval<Codec>().decode(std::declval<reader&>()));
+
+template <typename Codec, typename T, typename = void>
+struct is_codec : std::false_type {};
+
+template <typename Codec, typename T>
+struct is_codec<Codec, T, std::void_t<codec_encode_result_t<Codec, T>, codec_decode_result_t<Codec, T>>>
+  : std::true_type {};
+
+template <typename Codec, typename T>
+constexpr bool is_codec_v = is_codec<Codec, T>::value;
+
+template <typename Codec, typename T, typename = std::enable_if_t<is_codec_v<Codec, T>>>
+result<error> encode(Codec& codec, writer& writer, const T& value) {
+    return codec.encode(writer, value);
+}
+
+template <typename Codec, typename T, typename = std::enable_if_t<is_codec_v<Codec, T>>>
+result<error, T> decode(Codec& codec, reader& reader) {
+    return codec.decode(reader);
+}
+
+template <typename T, typename = void>
+class codec;
+
+template <typename T>
+struct codec<T, std::enable_if_t<std::is_integral_v<T>>> {
+    result<error>    encode(writer& writer, const T& value) { return writer.write_int(value); }
+    result<error, T> decode(reader& reader) { return reader.read_int(T{}); }
+};
+
+template <>
+struct codec<std::string> {
+    result<error> encode(writer& writer, const std::string& value) { return writer.write_string(value); }
+
+    result<error, std::string> decode(reader& reader) { return reader.read_string(); }
+};
+
+} // namespace serialization
+} // namespace furlang
+
+#endif // FURLANG_SERIALIZATION_CODEC_HPP

furlang/include/furlang/serialization/error.hpp

@@ -0,0 +1,33 @@
+#ifndef FURLANG_SERIALIZATION_ERROR_HPP
+#define FURLANG_SERIALIZATION_ERROR_HPP
+
+#include <cstddef>
+#include <string>
+
+namespace furlang {
+namespace serialization {
+
+enum class error_code {
+    EndOfFile,
+    InvalidData,
+    InvalidTag,
+    InvalidVersion,
+    IntegerOverflow,
+    SizeLimit,
+    DuplicateId,
+    UnknownId,
+    TypeMismatch,
+    Unsupported,
+};
+
+struct error {
+    error_code  code;
+    std::string message;
+
+    std::size_t offset = 0;
+};
+
+} // namespace serialization
+} // namespace furlang
+
+#endif // FURLANG_SERIALIZATION_ERROR_HPP

furlang/include/furlang/serialization/io.hpp

@@ -0,0 +1,190 @@
+#ifndef FURLANG_SERIALIZATION_IO_HPP
+#define FURLANG_SERIALIZATION_IO_HPP
+
+#include "furlang/result.hpp"
+#include "furlang/serialization/error.hpp"
+
+#include <cstdint>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+namespace furlang {
+namespace serialization {
+
+class writer {
+public:
+    writer()          = default;
+    virtual ~writer() = default;
+
+    writer(writer&&) noexcept            = default;
+    writer& operator=(writer&&) noexcept = default;
+    writer(const writer&)                = default;
+    writer& operator=(const writer&)     = default;
+public:
+    virtual result<error> write_s8(std::int8_t value)    = 0;
+    virtual result<error> write_u8(std::uint8_t value)   = 0;
+    virtual result<error> write_s16(std::int16_t value)  = 0;
+    virtual result<error> write_u16(std::uint16_t value) = 0;
+    virtual result<error> write_s32(std::int32_t value)  = 0;
+    virtual result<error> write_u32(std::uint32_t value) = 0;
+    virtual result<error> write_s64(std::int64_t value)  = 0;
+    virtual result<error> write_u64(std::uint64_t value) = 0;
+
+    result<error> write_int(std::int8_t value) { return write_s8(value); }
+    result<error> write_int(std::uint8_t value) { return write_u8(value); }
+    result<error> write_int(std::int16_t value) { return write_s16(value); }
+    result<error> write_int(std::uint16_t value) { return write_u16(value); }
+    result<error> write_int(std::int32_t value) { return write_s32(value); }
+    result<error> write_int(std::uint32_t value) { return write_u32(value); }
+    result<error> write_int(std::int64_t value) { return write_s64(value); }
+    result<error> write_int(std::uint64_t value) { return write_u64(value); }
+
+    virtual result<error> write_string(const char* string)        = 0;
+    virtual result<error> write_string(std::string_view string)   = 0;
+    virtual result<error> write_string(const std::string& string) = 0;
+};
+
+class reader {
+public:
+    reader()          = default;
+    virtual ~reader() = default;
+
+    reader(reader&&) noexcept            = default;
+    reader& operator=(reader&&) noexcept = default;
+    reader(const reader&)                = default;
+    reader& operator=(const reader&)     = default;
+public:
+    virtual result<error, std::int8_t>   read_s8()  = 0;
+    virtual result<error, std::uint8_t>  read_u8()  = 0;
+    virtual result<error, std::int16_t>  read_s16() = 0;
+    virtual result<error, std::uint16_t> read_u16() = 0;
+    virtual result<error, std::int32_t>  read_s32() = 0;
+    virtual result<error, std::uint32_t> read_u32() = 0;
+    virtual result<error, std::int64_t>  read_s64() = 0;
+    virtual result<error, std::uint64_t> read_u64() = 0;
+
+    result<error, std::int8_t>   read_int(std::int8_t) { return read_s8(); }
+    result<error, std::uint8_t>  read_int(std::uint8_t) { return read_u8(); }
+    result<error, std::int16_t>  read_int(std::int16_t) { return read_s16(); }
+    result<error, std::uint16_t> read_int(std::uint16_t) { return read_u16(); }
+    result<error, std::int32_t>  read_int(std::int32_t) { return read_s32(); }
+    result<error, std::uint32_t> read_int(std::uint32_t) { return read_u32(); }
+    result<error, std::int64_t>  read_int(std::int64_t) { return read_s64(); }
+    result<error, std::uint64_t> read_int(std::uint64_t) { return read_u64(); }
+
+    virtual result<error, std::string> read_string() = 0;
+
+    virtual std::size_t offset() const = 0;
+};
+
+enum class endianness {
+    Little = 0,
+    Big    = 1,
+};
+
+class byte_writer : public writer {
+public:
+    byte_writer(endianness endianness = endianness::Big)
+      : m_endianness(endianness) {}
+public:
+    result<error> write_s8(std::int8_t value) override;
+    result<error> write_u8(std::uint8_t value) override;
+    result<error> write_s16(std::int16_t value) override;
+    result<error> write_u16(std::uint16_t value) override;
+    result<error> write_s32(std::int32_t value) override;
+    result<error> write_u32(std::uint32_t value) override;
+    result<error> write_s64(std::int64_t value) override;
+    result<error> write_u64(std::uint64_t value) override;
+
+    result<error> write_string(const char* string) override;
+    result<error> write_string(std::string_view string) override;
+    result<error> write_string(const std::string& string) override;
+private:
+    template <typename T, typename = std::enable_if_t<std::is_integral_v<T>>>
+    result<error> write_integral_le(T value) {
+        return write_integral_le(value, std::make_index_sequence<sizeof(T)>{});
+    }
+
+    template <typename T, typename = std::enable_if_t<std::is_integral_v<T>>, std::size_t... I>
+    result<error> write_integral_le(T value, std::index_sequence<I...>) {
+        auto usig = static_cast<std::make_unsigned_t<T>>(value);
+        (m_bytes.push_back(usig >> (I * 8)), ...);
+        return {};
+    }
+private:
+    template <typename T, typename = std::enable_if_t<std::is_integral_v<T>>>
+    void write_integral_be(T value) {
+        write_integral_be(value, std::make_index_sequence<sizeof(T)>{});
+    }
+
+    template <typename T, typename = std::enable_if_t<std::is_integral_v<T>>, std::size_t... I>
+    void write_integral_be(T value, std::index_sequence<I...>) {
+        auto usig = static_cast<std::make_unsigned_t<T>>(value);
+        (m_bytes.push_back(usig >> ((sizeof(T) - 1 - I) * 8)), ...);
+    }
+private:
+    endianness                m_endianness;
+    std::vector<std::uint8_t> m_bytes;
+};
+
+class byte_reader : public reader {
+public:
+    byte_reader(const std::uint8_t* bytes, std::size_t length, endianness endianness = endianness::Big)
+      : m_endianness(endianness), m_bytes(bytes), m_length(length) {}
+public:
+    result<error, std::int8_t>   read_s8() override;
+    result<error, std::uint8_t>  read_u8() override;
+    result<error, std::int16_t>  read_s16() override;
+    result<error, std::uint16_t> read_u16() override;
+    result<error, std::int32_t>  read_s32() override;
+    result<error, std::uint32_t> read_u32() override;
+    result<error, std::int64_t>  read_s64() override;
+    result<error, std::uint64_t> read_u64() override;
+
+    result<error, std::string> read_string() override;
+
+    std::size_t offset() const override;
+private:
+    result<error, std::uint8_t> read_byte() {
+        if (m_offset >= m_length)
+            return result<error, std::uint8_t>::error(error{ error_code::EndOfFile, "", m_offset });
+        return { m_bytes[m_offset++] };
+    }
+private:
+    template <typename T, typename = std::enable_if_t<std::is_integral_v<T>>>
+    result<error, T> read_integral_le() {
+        using U = std::make_unsigned_t<T>;
+        U usig  = 0;
+        for (std::size_t i = 0; i < sizeof(T); ++i) {
+            auto res = read_byte();
+            if (res.has_error()) return res;
+            usig |= static_cast<U>(res.value()) << (i * 8);
+        }
+        return { static_cast<T>(usig) };
+    }
+private:
+    template <typename T, typename = std::enable_if_t<std::is_integral_v<T>>>
+    result<error, T> read_integral_be() {
+        using U = std::make_unsigned_t<T>;
+        U usig  = 0;
+        for (std::size_t i = 0; i < sizeof(T); ++i) {
+            auto res = read_byte();
+            if (res.has_error()) return res;
+            usig |= static_cast<U>(res.value()) << ((sizeof(T) - 1 - i) * 8);
+        }
+        return { static_cast<T>(usig) };
+    }
+private:
+    endianness          m_endianness;
+    const std::uint8_t* m_bytes;
+    std::size_t         m_length;
+    std::size_t         m_offset = 0;
+};
+
+} // namespace serialization
+} // namespace furlang
+
+#endif // FURLANG_SERIALIZATION_IO_HPP

furlang/src/serialization/io.cpp

@@ -0,0 +1,137 @@
+#include "furlang/serialization/io.hpp"
+
+#include <cstring>
+
+namespace furlang::serialization {
+
+result<error> byte_writer::write_s8(std::int8_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_u8(std::uint8_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_s16(std::int16_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_u16(std::uint16_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_s32(std::int32_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_u32(std::uint32_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_s64(std::int64_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_u64(std::uint64_t value) {
+    if (m_endianness == endianness::Little)
+        write_integral_le(value);
+    else
+        write_integral_be(value);
+    return {};
+}
+
+result<error> byte_writer::write_string(const char* string) {
+    write_u16(std::strlen(string));
+    m_bytes.insert(m_bytes.end(), string, string + std::strlen(string));
+    return {};
+}
+
+result<error> byte_writer::write_string(std::string_view string) {
+    write_u16(string.length());
+    m_bytes.insert(m_bytes.end(), string.begin(), string.end());
+    return {};
+}
+
+result<error> byte_writer::write_string(const std::string& string) {
+    write_u16(string.length());
+    m_bytes.insert(m_bytes.end(), string.begin(), string.end());
+    return {};
+}
+
+result<error, std::int8_t> byte_reader::read_s8() {
+    return m_endianness == endianness::Little ? read_integral_le<std::int8_t>() : read_integral_be<std::int8_t>();
+}
+
+result<error, std::uint8_t> byte_reader::read_u8() {
+    return m_endianness == endianness::Little ? read_integral_le<std::uint8_t>() : read_integral_be<std::uint8_t>();
+}
+
+result<error, std::int16_t> byte_reader::read_s16() {
+    return m_endianness == endianness::Little ? read_integral_le<std::int16_t>() : read_integral_be<std::int16_t>();
+}
+
+result<error, std::uint16_t> byte_reader::read_u16() {
+    return m_endianness == endianness::Little ? read_integral_le<std::uint16_t>() : read_integral_be<std::uint16_t>();
+}
+
+result<error, std::int32_t> byte_reader::read_s32() {
+    return m_endianness == endianness::Little ? read_integral_le<std::int32_t>() : read_integral_be<std::int32_t>();
+}
+
+result<error, std::uint32_t> byte_reader::read_u32() {
+    return m_endianness == endianness::Little ? read_integral_le<std::uint32_t>() : read_integral_be<std::uint32_t>();
+}
+
+result<error, std::int64_t> byte_reader::read_s64() {
+    return m_endianness == endianness::Little ? read_integral_le<std::int64_t>() : read_integral_be<std::int64_t>();
+}
+
+result<error, std::uint64_t> byte_reader::read_u64() {
+    return m_endianness == endianness::Little ? read_integral_le<std::uint64_t>() : read_integral_be<std::uint64_t>();
+}
+
+result<error, std::string> byte_reader::read_string() {
+    std::string str;
+    auto        length = read_u16();
+    if (length.has_error()) return length;
+    str.resize(length.value());
+    if (m_offset + str.length() >= m_length)
+        return result<error, std::string>::error(error{ error_code::EndOfFile, "", m_length });
+    str.assign(reinterpret_cast<const char*>(m_bytes) + m_offset, str.length());
+    m_offset += str.length();
+    return str;
+}
+
+std::size_t byte_reader::offset() const {
+    return m_offset;
+}
+
+} // namespace furlang::serialization