Creating function stubs for a type to implement an interface

[fluhus]

Hi gophers,

Is there a way in vscode-go to automatically generate functions for a type in order for it to implement an interface?

For example:

type Cow interface {
  Moo() string
  Weight() float64
}
type Fjall struct{}

~~ magic ~~

// Auto-generated, Fjall now implements Cow.
func (f Fjall) Moo string {}
func (f Fjall) Weight float64 {}

[xiebruce]

use impl, first install it

go install github.com/josharian/impl@latest

Assume that you have a main.go, the code is as below

package main

type Cow interface {
	Moo() string
	Weight() float64
}
type Fjall struct{}

func main() {

}

In terminal, cd to the directory where the main.go located

cd /path/to/dir/

Use the following command

impl "f Fjall" Cow

it will output these code

func (f Fjall) Moo() string {
        panic("not implemented") // TODO: Implement
}

func (f Fjall) Weight() float64 {
        panic("not implemented") // TODO: Implement
}

If the interface is from standard library, you don't need to cd to the directory, for example

impl "f Fjall" hash.Hash

will output

func (f Fjall) Write(p []byte) (n int, err error) {
	panic("not implemented") // TODO: Implement
}

// Sum appends the current hash to b and returns the resulting slice.
// It does not change the underlying hash state.
func (f Fjall) Sum(b []byte) []byte {
	panic("not implemented") // TODO: Implement
}

// Reset resets the Hash to its initial state.
func (f Fjall) Reset() {
	panic("not implemented") // TODO: Implement
}

// Size returns the number of bytes Sum will return.
func (f Fjall) Size() int {
	panic("not implemented") // TODO: Implement
}

// BlockSize returns the hash's underlying block size.
// The Write method must be able to accept any amount
// of data, but it may operate more efficiently if all writes
// are a multiple of the block size.
func (f Fjall) BlockSize() int {
	panic("not implemented") // TODO: Implement
}

[fluhus]

Thanks! Looks great, didn't know about this library.