flagpb

Documentation

Overview

Package flagpb defines a flag format for protobuf messages, implements a parser and a formatter.

Currently flagpb supports only untyped messages, not proto.Message. Support for the latter could be added too.

Syntax

Flag syntax by example. First line is flagpb, second is jsonpb.

-x=42 -b -s hello
{"x": 42, "b": true, "s": "hello"}

-m.x 3 -m.s world
{"m": {"x": 3, "s": "world"}}

-rx 1 -rx 2
{"rx": [1, 2]}

-rm.x 1 -rm -rm.x 2
{"rm": [{"x": 1}, {"x": 2}]}

where x fields are int32, m are message fields, b are boolean and s are strings. Fields with "r" prefix are repeated.

Bytes field values are decoded from hex, e.g. "FF02AB".

Enum field values can be specified by enum member name or number.

Index

• func MarshalUntyped(msg map[string]any) ([]string, error)
• func UnmarshalMessage(flags []string, resolver Resolver, msg proto.Message) error
• func UnmarshalUntyped(flags []string, desc *descriptorpb.DescriptorProto, resolver Resolver) (map[string]any, error)
• type Resolver
  • func NewResolver(set *descriptorpb.FileDescriptorSet) Resolver

Functions

func MarshalUntyped

func MarshalUntyped(msg map[string]any) ([]string, error)

MarshalUntyped marshals a key-value map to flags.

func UnmarshalMessage

func UnmarshalMessage(flags []string, resolver Resolver, msg proto.Message) error

UnmarshalMessage unmarshals the proto message from flags.

The descriptor set should be obtained from the `cproto` compiled packages' FileDescriptorSet() method.

func UnmarshalUntyped

func UnmarshalUntyped(flags []string, desc *descriptorpb.DescriptorProto, resolver Resolver) (map[string]any, error)

UnmarshalUntyped unmarshals a key-value map from flags using a protobuf message descriptor.

Types

type Resolver

type Resolver interface {
	// Resolve resolves a type name to
	// *descriptor.DescriptorProto or *descriptor.EnumDescriptorProto.
	Resolve(name string) any
}

Resolver resolves type names.

func NewResolver

func NewResolver(set *descriptorpb.FileDescriptorSet) Resolver

NewResolver creates a resolver for all types in a file descriptor set. Resolving time complexity is linear.