Include keyify support

[thalesmello]

Includes support for https://github.com/dominikh/go-tools/tree/master/cmd/keyify
through the GoKeyify command.

It turns unkeyed struct literals into keyed struct literals.

[fatih]

This is a wrong import path, should be: github.com/dominikh/go-tools/cmd/keyify

[thalesmello]

Thanks. Changed it.

[fatih]

Hi @thalesmello

I just tried it. The example I've used is:

package main

import "fmt"

type Foo struct {
	foo string
	bar string
	qux string
}

func main() {
	f := Foo{"foo", "bar", "qux"}
	fmt.Printf("f = %+v\n", f)
}

1. When I put my cursor on top of f or before Foo nothing happens. I think we should support that case, not sure if we can do it without adding support to keyify. If not we should return a message saying that the cursor is not on top of the struct. keyify already does it, we should display it.

2. If I put my cursor on Foo it converts it to:

package main

import "fmt"

type Foo struct {
	foo string
	bar string
	qux string
}

func main() {
	Foo{
		foo: "foo",
		bar: "bar",
		qux: "qux",
	}
	fmt.Printf("f = %+v\n", f)
}

As you see it removes the variable all together. I assume the replacement is not done correctly.

[thalesmello]

@fatih

I think we could implement some kind of mechanism to try to figure out the position of the struct, however, I can't think of a good way of implementing it in a good, clear way.

But I totally agree that it at least should output some nice error message.

In my first implementation, I simply did nothing when I keyify didn't return a refactor.

What I did, then, was simply return keyify's error message, which is actually pretty useful.

Now it returns

Error detected while processing function go#keyify#Keyify:
line   18:
no composite literal found near point

When it doesn't find any struct. What do you think about this?

Hum, strange. It work correctly for me.

A common issue with keyify is that it has to run inside the $GOPATH/src folder, otherwise it isn't able to work.

Could you please check my changes?

[fatih]

When it doesn't find any struct. What do you think about this?

Do not use echoerr. Instead use our own echo messages as echoerr is not user friendly. Here is an example:

    call go#util#EchoError(s:chomp(output))

A common issue with keyify is that it has to run inside the $GOPATH/src folder, otherwise it isn't able to work.

How do we know that it doesn't work. Does it return an error? I'm always inside a GOPATH. vim-go also has with Go 1.8 a default GOPATH as well.

Hum, strange. It work correctly for me.

The problem occurs if you previously have selected anything. For example do a line seletion via "shift-v" and then call :GoKeyify when your cursor is on Foo, you'll see it'll replace with the wrong selection.

[thalesmello]

@fatih

I changed the echo function used.

About the bug, here is what happened:

1. You used a "V" visual mode
2. GoKeyify relies on using a visual range in order to replace some text
3. Because the previous visual mode was "V", it's used when you type "gv"
4. GoKeyify replaces the entire lines content because of this

In order to prevent this bug, now the function checks if the correct visual mode is being used.

Could you check this last version, please?

[fatih]

Thanks @thalesmello this looks now good 👍