Types

PBExplicit = PBOption: Source Edit
PBOption[defaultValue] = object: Optional value type for protobuf fields. Allows distinguishing between "field not set" and "field set to default value". Only works with proto2. Source Edit
ProtobufEOFError = object of ProtobufReadError: Error raised when unexpected end of input is encountered. Source Edit
ProtobufError = object of SerializationError: Error raised when a protobuf decoding/encoding operation fails. Source Edit
ProtobufExt[FieldType; RootType; fieldName] = object: Type marker for protobuf extension types. Used internally for type extensions. Source Edit
ProtobufFlags = enum VarIntLengthPrefix ## Flags that control protobuf encoding behavior.: Source Edit
ProtobufGroupError = object of ProtobufValueError: Error raised when a group (deprecated protobuf feature) is encountered. Source Edit
ProtobufMessageError = object of ProtobufReadError: Error raised when a message structure is invalid. Source Edit
ProtobufReader = ref object stream*: InputStream closeAfter*: bool: Reader for decoding protobuf format to Nim objects. Source Edit
ProtobufReadError = object of ProtobufError: Error raised when reading a protobuf message fails. Source Edit
ProtobufValueError = object of ProtobufReadError: Error raised when a field value is invalid. Source Edit
ProtobufWriter = object stream*: OutputStream flags*: set[ProtobufFlags]: Writer for encoding Nim objects to protobuf format. Source Edit

Procs

proc finish(writer: ProtobufWriter): seq[byte] {....raises: [IOError], raises: [], gcsafe, tags: [RootEffect], forbids: [].}: Source Edit
func get(opt: PBOption): auto {....raises: [], gcsafe.}: Returns the value if set, otherwise returns the default value. Source Edit
func init(opt: var PBOption; val: auto) {....raises: [], gcsafe.}: Source Edit
func init(T: type ProtobufReader; stream: InputStream; closeAfter: bool = true): T:type {. inline, ...raises: [], gcsafe.}: Source Edit
func init(T: type ProtobufWriter; stream: OutputStream; flags: static set[ProtobufFlags] = {}): T:type {.inline, ...raises: [], gcsafe.}: Source Edit
func isNone(opt: PBOption): bool {.inline, ...raises: [], gcsafe.}: Returns true if the optional value is not set. Source Edit
func isSome(opt: PBOption): bool {.inline, ...raises: [], gcsafe.}: Returns true if the optional value is set. Source Edit
func pbSome[T: PBOption](optType: typedesc[T]; value: auto): T {.inline, ...raises: [], gcsafe.}: Creates a PBOption with the given value marked as set. Use this to create optional values that are present. Source Edit

Converters

converter toValue(opt: PBOption): auto {.inline, ...raises: [], gcsafe.}: Source Edit

Templates

template ext() {.pragma.}: Pragma to mark a field as using a type extension. The field's type must have custom serialization logic defined via computeFieldSize, writeField, and readFieldInto. Source Edit
template fieldNumber(num: int) {.pragma.}: Pragma to assign a field number to a protobuf field. Required for all fields. Field numbers must be unique within a message and should never change. Source Edit
template fixed() {.pragma.}: Pragma for fixed-width encoding. Always uses 4 or 8 bytes regardless of value. Use for large values or when predictable size matters. Use for fixed32, fixed64, sfixed32, sfixed64. Source Edit
template implicit() {.pragma.}: Source Edit
template mget(opt: var PBOption): untyped {..}: Returns a mutable reference to the value, marking it as set. Use this to modify the value in place. Source Edit
template oneof() {.pragma.}: Pragma to mark a field as a oneof (union type). Only one field in the oneof can be set at a time. Source Edit
template packed(v: bool) {.pragma.}: Pragma to enable packed encoding for repeated fields. More efficient for scalar numeric types. All elements are encoded as a single length-delimited field instead of separate entries. Source Edit
template pbNone(value: untyped): untyped {..}: Creates a PBOption marked as not set (absent). The parameter specifies the default value type. Source Edit
template pbSome(value: untyped): untyped {..}: Creates a PBOption with the given value marked as set. The default value is inferred from the type of the value. Shorthand for pbSome(PBOption[...], value). Source Edit
template pint() {.pragma.}: Pragma for "plain int" encoding using standard varint. Efficient for positive values, inefficient for negative values. Use for int32, int64, uint32, uint64. Source Edit
template proto(edition = 2023) {.pragma.}: Source Edit
template proto2() {.pragma.}: Pragma to mark a type as using Protocol Buffers version 2 syntax. Proto2 supports required fields and explicit optional fields. Source Edit
template proto3() {.pragma.}: Pragma to mark a type as using Protocol Buffers version 3 syntax. Proto3 has implicit default values and no required keyword. Source Edit
template required() {.pragma.}: Pragma to mark a proto2 field as required. The field must be present in encoded messages. Only available in proto2; proto3 does not support required fields. Source Edit
template sint() {.pragma.}: Pragma for "signed int" encoding using zig-zag varint. Efficient for negative values. Use for int32, int64 when negative values are common. Source Edit
template valueOr(opt: PBOption; def: untyped): untyped {..}: Returns the value if set, otherwise returns the provided default. Unlike get, this allows you to specify a custom default at call site. Source Edit

protobuf_serialization/types

Types

Procs

Converters

Templates