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https://github.com/abice/go-enum
An enum generator for go
https://github.com/abice/go-enum
enum generated go golang
Last synced: 10 days ago
JSON representation
An enum generator for go
- Host: GitHub
- URL: https://github.com/abice/go-enum
- Owner: abice
- License: mit
- Created: 2017-08-10T22:07:31.000Z (about 7 years ago)
- Default Branch: master
- Last Pushed: 2024-07-29T02:06:53.000Z (3 months ago)
- Last Synced: 2024-07-31T20:51:43.576Z (3 months ago)
- Topics: enum, generated, go, golang
- Language: Go
- Size: 7.37 MB
- Stars: 705
- Watchers: 7
- Forks: 54
- Open Issues: 9
-
Metadata Files:
- Readme: README.md
- License: LICENSE
- Codeowners: CODEOWNERS
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- awesome-go-extra - go-enum - 08-10T22:07:31Z|2022-08-24T13:05:45Z| (Generators / Utility/Miscellaneous)
README
# go-enum
[](https://github.com/abice/go-enum/actions/workflows/build_and_test.yml)
[](https://goreportcard.com/report/github.com/abice/go-enum)
[](https://coveralls.io/github/abice/go-enum)
[](https://godoc.org/github.com/abice/go-enum)
[](https://github.com/avelino/awesome-go)
An enum generator for go
## How it works
go-enum will take a commented type declaration like this:
```go
// ENUM(jpeg, jpg, png, tiff, gif)
type ImageType int
```
and generate a file with the iota definition along various optional niceties that you may need:
```go
const (
// ImageTypeJpeg is a ImageType of type Jpeg.
ImageTypeJpeg ImageType = iota
// ImageTypeJpg is a ImageType of type Jpg.
ImageTypeJpg
// ImageTypePng is a ImageType of type Png.
ImageTypePng
// ImageTypeTiff is a ImageType of type Tiff.
ImageTypeTiff
// ImageTypeGif is a ImageType of type Gif.
ImageTypeGif
)
// String implements the Stringer interface.
func (x ImageType) String() string
// ParseImageType attempts to convert a string to a ImageType.
func ParseImageType(name string) (ImageType, error)
// MarshalText implements the text marshaller method.
func (x ImageType) MarshalText() ([]byte, error)
// UnmarshalText implements the text unmarshaller method.
func (x *ImageType) UnmarshalText(text []byte) error
```
**Fear not the fact that the `MarshalText` and `UnmarshalText` are generated rather than JSON methods... they will still be utilized by the default JSON encoding methods.**
If you find that the options given are not adequate for your use case, there is an option to add a custom template (`-t` flag) to the processing engine so that your custom code can be created!
## Now with string typed enums
```go
// ENUM(pending, running, completed, failed)
type StrState string
```
```go
const (
// StrStatePending is a StrState of type pending.
StrStatePending StrState = "pending"
// StrStateRunning is a StrState of type running.
StrStateRunning StrState = "running"
// StrStateCompleted is a StrState of type completed.
StrStateCompleted StrState = "completed"
// StrStateFailed is a StrState of type failed.
StrStateFailed StrState = "failed"
)
```
If you would like to get integer values in sql, but strings elsewhere, you can assign an int value in the declaration
like always, and specify the `--sqlint` flag. Those values will be then used to convey the int value to sql, while allowing you to use only strings elsewhere.
This might be helpful for things like swagger docs where you want the same type being used on the api layer, as you do in the
sql layer, and not have swagger assume that your enumerations are integers, but are in fact strings!
```go
// swagger:enum StrState
// ENUM(pending, running, completed, failed)
type StrState string
```
## Goal
The goal of go-enum is to create an easy to use enum generator that will take a decorated type declaration like `type EnumName int` and create the associated constant values and funcs that will make life a little easier for adding new values.
It's not perfect, but I think it's useful.
I took the output of the [Stringer](https://godoc.org/golang.org/x/tools/cmd/stringer) command as the `String()` method, and added a way to parse a string value.
## Docker image
You can now use a docker image directly for running the command if you do not wish to install anything!
```shell
docker run -w /app -v $(pwd):/app abice/go-enum:$(GO_ENUM_VERSION)
```
## Installation
You can now download a release directly from github and use that for generating your enums! (Thanks to [GoReleaser](https://github.com/goreleaser/goreleaser-action))
I did not specify any overrides on the release binary names, so `uname -s` and `uname -m` should provide the correct version of the binary for your distro.
```shell
curl -fsSL "https://github.com/abice/go-enum/releases/download/$(GO_ENUM_VERSION)/go-enum_$(uname -s)_$(uname -m)" -o go-enum
```
## Adding it to your project
### Using go generate
1. Add a go:generate line to your file like so... `//go:generate go-enum --marshal`
1. Run go generate like so `go generate ./...`
1. Enjoy your newly created Enumeration!
### Using Makefile
If you prefer makefile stuff, you can always do something like this:
```Makefile
STANDARD_ENUMS = ./example/animal_enum.go \
./example/color_enum.go
NULLABLE_ENUMS = ./example/sql_enum.go
$(STANDARD_ENUMS): GO_ENUM_FLAGS=--nocase --marshal --names --ptr
$(NULLABLE_ENUMS): GO_ENUM_FLAGS=--nocase --marshal --names --sqlnullint --ptr
enums: $(STANDARD_ENUMS) $(NULLABLE_ENUMS)
# The generator statement for go enum files. Files that invalidate the
# enum file: source file, the binary itself, and this file (in case you want to generate with different flags)
%_enum.go: %.go $(GOENUM) Makefile
$(GOENUM) -f $*.go $(GO_ENUM_FLAGS)
```
## Command options
``` shell
go-enum --help
NAME:
go-enum - An enum generator for go
USAGE:
go-enum [global options] [arguments...]
VERSION:
example
GLOBAL OPTIONS:
--file value, -f value [ --file value, -f value ] The file(s) to generate enums. Use more than one flag for more files. [$GOFILE]
--noprefix Prevents the constants generated from having the Enum as a prefix. (default: false)
--lower Adds lowercase variants of the enum strings for lookup. (default: false)
--nocase Adds case insensitive parsing to the enumeration (forces lower flag). (default: false)
--marshal Adds text (and inherently json) marshalling functions. (default: false)
--sql Adds SQL database scan and value functions. (default: false)
--sqlint Tells the generator that a string typed enum should be stored in sql as an integer value. (default: false)
--flag Adds golang flag functions. (default: false)
--prefix value Adds a prefix with a user one. If you would like to replace the prefix, then combine this option with --noprefix.
--names Generates a 'Names() []string' function, and adds the possible enum values in the error response during parsing (default: false)
--values Generates a 'Values() []{{ENUM}}' function. (default: false)
--nocamel Removes the snake_case to CamelCase name changing (default: false)
--ptr Adds a pointer method to get a pointer from const values (default: false)
--sqlnullint Adds a Null{{ENUM}} type for marshalling a nullable int value to sql (default: false)
--sqlnullstr Adds a Null{{ENUM}} type for marshalling a nullable string value to sql. If sqlnullint is specified too, it will be Null{{ENUM}}Str (default: false)
--template value, -t value [ --template value, -t value ] Additional template file(s) to generate enums. Use more than one flag for more files. Templates will be executed in alphabetical order.
--alias value, -a value [ --alias value, -a value ] Adds or replaces aliases for a non alphanumeric value that needs to be accounted for. [Format should be "key:value,key2:value2", or specify multiple entries, or both!]
--mustparse Adds a Must version of the Parse that will panic on failure. (default: false)
--forcelower Forces a camel cased comment to generate lowercased names. (default: false)
--forceupper Forces a camel cased comment to generate uppercased names. (default: false)
--nocomments Removes auto generated comments. If you add your own comments, these will still be created. (default: false)
--buildtag value, -b value [ --buildtag value, -b value ] Adds build tags to a generated enum file.
--help, -h show help
--version, -v print the version
```
### Syntax
The parser looks for comments on your type defs and parse the enum declarations from it.
The parser will look for `ENUM(` and continue to look for comma separated values until it finds a `)`. You can put values on the same line, or on multiple lines.\
If you need to have a specific value jump in the enum, you can now specify that by adding `=numericValue` to the enum declaration. Keep in mind, this resets the data for all following values. So if you specify `50` in the middle of an enum, each value after that will be `51, 52, 53...`
[Examples can be found in the example folder](./example/)
#### Comments
You can use comments inside enum that start with `//`\
The comment must be at the end of the same line as the comment value, only then it will be added as a comment to the generated constant.
```go
// Commented is an enumeration of commented values
/*
ENUM(
value1 // Commented value 1
value2
value3 // Commented value 3
)
*/
type Commented int
```
The generated comments in code will look something like:
```go
...
const (
// CommentedValue1 is a Commented of type Value1
// Commented value 1
CommentedValue1 Commented = iota
// CommentedValue2 is a Commented of type Value2
CommentedValue2
// CommentedValue3 is a Commented of type Value3
// Commented value 3
CommentedValue3
)
...
```
#### Example
There are a few examples in the `example` [directory](./example/).
I've included one here for easy access, but can't guarantee it's up to date.
``` go
// Color is an enumeration of colors that are allowed.
/* ENUM(
Black, White, Red
Green = 33 // Green starts with 33
*/
// Blue
// grey=
// yellow
// blue-green
// red-orange
// yellow_green
// red-orange-blue
// )
type Color int32
```
The generated code will look something like:
``` go
// Code generated by go-enum DO NOT EDIT.
// Version: example
// Revision: example
// Build Date: example
// Built By: example
package example
import (
"fmt"
"strings"
)
const (
// ColorBlack is a Color of type Black.
ColorBlack Color = iota
// ColorWhite is a Color of type White.
ColorWhite
// ColorRed is a Color of type Red.
ColorRed
// ColorGreen is a Color of type Green.
// Green starts with 33
ColorGreen Color = iota + 30
// ColorBlue is a Color of type Blue.
ColorBlue
// ColorGrey is a Color of type Grey.
ColorGrey
// ColorYellow is a Color of type Yellow.
ColorYellow
// ColorBlueGreen is a Color of type Blue-Green.
ColorBlueGreen
// ColorRedOrange is a Color of type Red-Orange.
ColorRedOrange
// ColorYellowGreen is a Color of type Yellow_green.
ColorYellowGreen
// ColorRedOrangeBlue is a Color of type Red-Orange-Blue.
ColorRedOrangeBlue
)
const _ColorName = "BlackWhiteRedGreenBluegreyyellowblue-greenred-orangeyellow_greenred-orange-blue"
var _ColorMap = map[Color]string{
ColorBlack: _ColorName[0:5],
ColorWhite: _ColorName[5:10],
ColorRed: _ColorName[10:13],
ColorGreen: _ColorName[13:18],
ColorBlue: _ColorName[18:22],
ColorGrey: _ColorName[22:26],
ColorYellow: _ColorName[26:32],
ColorBlueGreen: _ColorName[32:42],
ColorRedOrange: _ColorName[42:52],
ColorYellowGreen: _ColorName[52:64],
ColorRedOrangeBlue: _ColorName[64:79],
}
// String implements the Stringer interface.
func (x Color) String() string {
if str, ok := _ColorMap[x]; ok {
return str
}
return fmt.Sprintf("Color(%d)", x)
}
var _ColorValue = map[string]Color{
_ColorName[0:5]: ColorBlack,
strings.ToLower(_ColorName[0:5]): ColorBlack,
_ColorName[5:10]: ColorWhite,
strings.ToLower(_ColorName[5:10]): ColorWhite,
_ColorName[10:13]: ColorRed,
strings.ToLower(_ColorName[10:13]): ColorRed,
_ColorName[13:18]: ColorGreen,
strings.ToLower(_ColorName[13:18]): ColorGreen,
_ColorName[18:22]: ColorBlue,
strings.ToLower(_ColorName[18:22]): ColorBlue,
_ColorName[22:26]: ColorGrey,
strings.ToLower(_ColorName[22:26]): ColorGrey,
_ColorName[26:32]: ColorYellow,
strings.ToLower(_ColorName[26:32]): ColorYellow,
_ColorName[32:42]: ColorBlueGreen,
strings.ToLower(_ColorName[32:42]): ColorBlueGreen,
_ColorName[42:52]: ColorRedOrange,
strings.ToLower(_ColorName[42:52]): ColorRedOrange,
_ColorName[52:64]: ColorYellowGreen,
strings.ToLower(_ColorName[52:64]): ColorYellowGreen,
_ColorName[64:79]: ColorRedOrangeBlue,
strings.ToLower(_ColorName[64:79]): ColorRedOrangeBlue,
}
// ParseColor attempts to convert a string to a Color
func ParseColor(name string) (Color, error) {
if x, ok := _ColorValue[name]; ok {
return x, nil
}
return Color(0), fmt.Errorf("%s is not a valid Color", name)
}
func (x Color) Ptr() *Color {
return &x
}
// MarshalText implements the text marshaller method
func (x Color) MarshalText() ([]byte, error) {
return []byte(x.String()), nil
}
// UnmarshalText implements the text unmarshaller method
func (x *Color) UnmarshalText(text []byte) error {
name := string(text)
tmp, err := ParseColor(name)
if err != nil {
return err
}
*x = tmp
return nil
}
```