gg

gg

gg is a General Golang Code Generator: A Good Game to play with Golang.

package main

import (
	"fmt"

	. "github.com/Xuanwo/gg"
)

func main() {
	f := NewGroup()
	f.AddPackage("main")
	f.NewImport().
		AddPath("fmt")
	f.NewFunction("main").AddBody(
		String(`fmt.Println("%s")`, "Hello, World!"),
	)
	fmt.Println(f.String())
}

Output (after go fmt)

package main

import "fmt"

func main() {
	fmt.Println("Hello, World!")
}

Design

gg is a general golang code generator that designed for resolving problems exists in the following tools:

• text/template: Additional syntax, Steep learning curve, Complex logic is difficult to maintain
• dave/jennifer: Overly abstract APIs, user need to take care about (), , everywhere.
• kubernetes-sigs/kubebuilder: Parse data from struct tags/comments, not a general code generator.

In short, gg will provide near-native golang syntax and helpful API so play a good game with Golang. With gg, we can generate golang code more easily and understandable.

Usage

Package Name

f := Group()
f.AddPackage("main")
// package main

Imports

f := Group()
f.NewImport().
    AddPath("context").
	AddDot("math").
	AddBlank("time").
	AddAlias("x", "testing")
// import (
//      "context"
//      . "math"
//      _ "time"
//      x "testing"
// )

Function

f := Group()
f.NewFunction("hello").
    WithReceiver("v", "*World").
    AddParameter("content", "string").
    AddParameter("times", "int").
    AddResult("v", "string").
    AddBody(gg.String(`return fmt.Sprintf("say %s in %d times", content, times)`))
// func (v *World) hello(content string, times int) (v string) {
//  return fmt.Sprintf("say %s in %d times", content, times)
//}

Struct

f := Group()
f.NewStruct("World").
    AddField("x", "int64").
    AddField("y", "string")
// type World struct {
//    x int64
//    y string
//}

Acknowledgement

• gg is inspired by dave/jennifer, I borrowed most ideas and some code from it. Nice work!