go install github.com/mrexox/gen-singleton-functions@latestAdd the following line in your source code
//go:generate gen-singleton-functions github.com/account/repo/package *MyTypeIf you want a value receiver then pass a type name without an asterisk
//go:generate gen-singleton-functions github.com/account/repo/package MyTypeMake Dog methods Bark and Validate public functions of a package dog.
// dog/dog.go package dog import "fmt" //go:generate gen-singleton-functions github.com/me/animals/dog *Dog type Dog struct { numTails int barkingSound string } func (d *Dog) Bark() string { return d.barkingSound } func (d *Dog) Validate() error { if d.numTails != 1 { return fmt.Errorf("unexpected number of tails: %d", d.numTails) } return nil }After running go generate ./... the resulting file will contain the following:
// dog/dog_gen.go // // Code generated by generator, DO NOT EDIT. // // This file provides the wrappers for exported methods of a global var `globalDog`. package dog var globalDog *Dog func SetGlobalDog(v *Dog) { globalDog = v } // Bark calls `globalDog.Bark`. func Bark() string { if globalDog == nil { panic("globalDog must be set before calling Bark()") } return globalDog.Bark() } // Validate calls `globalDog.Validate`. func Validate() error { if globalDog == nil { panic("globalDog must be set before calling Validate()") } return globalDog.Validate() }