gostringenum

gostringenum

gostringenum is a utility for generating encoding code for go enums that have string representations.

gostringenum aims to provide an efficient solution for small enumerations, but does not concern itself with enums that dozens of values. gostringenum also optionally generates tests for the generated code.

Defining Enums

gostringenum supports two different types of enums:

Enum With an Unknown Zero Value

An enum with an unknown zero value is a type of enum where the zero value signifies an unknown value, and the encoding/decoding can never fail, but defaults to the zero value instead. To define an enum with an unknown zero value, simply define an exported zero value:

type MyEnum int

const (
  MyEnumUnknown MyEnum = iota
  MyEnumA
  MyEnumB
)

var (
  myEnumStringUnknown = "unknown"
  myEnumStringA       = "a"
  myEnumStringB       = "b"
)

Enum With an Invalid Zero Value

An enum with an invalid zero value is a type of enum where any value other than the ones defined is considered invalid, and the encoding/decoding will fail upon encountering these values. To define an enum with an invalid zero value, don't define an exported zero value:

type MyEnum int

const (
  myEnumInvalid MyEnum = iota
  MyEnumA
  MyEnumB
)

var (
  myEnumStringA = "a"
  myEnumStringB = "b"
)

Usage

Recommended usage is to embed as a script to your project and use go:generate. This provides you with minimal setup, an easy upgrade path using standard toolchain, and a more obvious indication of where the code comes from.

// ./myenum.go

package mypkg

type MyEnum int

const (
  myEnumInvalid MyEnum = iota
  MyEnumA
  MyEnumB
)

var (
  myEnumStringA = "a"
  myEnumStringB = "b"
)

//go:generate go run generate/gostringenum.go -- -test-file . MyEnum myenum_encoding.go

// ./generate/gostringenum.go

package main

import "github.com/jussi-kalliokoski/gostringenum/cli"

func main() {
	cli.Run()
}

License

MIT License. See LICENSE for more details.