Presence = enum
  Singular, Repeated, Optional, Required

ProtoNode = ref object
  case kind*: ProtoType
  of Field:
    number*: int
    protoType*: string
    name*: string
    presence*: Presence
    options*: seq[ProtoNode]
  of Oneof:
    oneofName*: string
    oneof*: seq[ProtoNode]
  of Enum:
    enumName*: string
    values*: seq[ProtoNode]
  of EnumVal:
    fieldName*: string
    num*: int
    enumValOptions*: seq[ProtoNode]
  of ReservedBlock:
    resValues*: seq[ProtoNode]
  of Reserved:
    case reservedKind*: ReservedType
    of ReservedType.String:
      strVal*: string
    of ReservedType.Number:
      intVal*: int
    of ReservedType.Range:
      startVal*: int
      endVal*: int
  of Message:
    messageName*: string
    reserved*: seq[ProtoNode]
    definedEnums*: seq[ProtoNode]
    fields*: seq[ProtoNode]
    nested*: seq[ProtoNode]
  of Extend:
    extending*: string
    extendedFields*: seq[ProtoNode]
  of Package:
    packageName*: string
    messages*: seq[ProtoNode]
    packageEnums*: seq[ProtoNode]
    services*: seq[ProtoNode]
  of File:
    syntax*: string
    imported*: seq[ProtoNode]
    package*: ProtoNode
  of ProtoDef:
    packages*: seq[ProtoNode]
  of Imported:
    filename*: string
  of FieldOption:
    optName*: string
    optVal*: string
  of Service:
    serviceName*: string
    rpcs*: seq[ProtoNode]
  of Rpc:
    rpcName*: string
    rpcParamStream*: bool
    rpcParam*: string
    rpcReturns*: string
    rpcReturnsStream*: bool

ProtoType = enum
  Field, Enum, EnumVal, ReservedBlock, Reserved, Message, File, Imported, Oneof,
  Package, ProtoDef, Extend, FieldOption, Service, Rpc

ReservedType = enum
  String, Number, Range