[WIP] import declaration autocomplete

[nhooyr]

This closes issue #257. Work in progress right now.

Detection of being inside an import statement is done. Here is a testing file.

package main

import "fmt"

import f "fmt"

import . "fmt"

import (
    "fmt"
)

import (
    "fmt"
    "log"
)

import (
    f "fmt"
    l "log"
)

import (
    . "fmt"
    l "log"
)

import (
    "fmt"; "log"
)

import (
    . "fmt"; l "log"
)

import _ "fmt"

import (
  "io/
)

I just need to take cc.partial and return all import paths that match.

[nhooyr]

Alright now it works, autocomplete is functioning, I'm gonna just polish it up.

[nhooyr]

The plugins will need an update as well. I'll also take a look at vendoring/gb.

edit: never mind plugins are fine, I was making a mistake.

[nsf]

The plugins will need an update as well.

That's a really bad joke.

Aside from that I see some bugs, the import doesn't return the correct length of the partial in some cases. That's a second argument form func (c *auto_complete_context) apropos, it's very important because some editors rely on it. Vim and godit in particular. I'll see more into code and will comment it there.

[nsf]

Okay, the problem with partial length seems to be the following.

If I do autocompletion here: import "encoding/j#son" (# is the cursor).

The returned length of the partial is: len("encoding/j"), but the candidate itself is "json". It's incorrect. You should return the full "encoding/json" candidate in that case or reduce the returned partial length to be len("j"). Again, length of partial is a second argument returned by apropos method, some editors rely on it.

[nhooyr]

Got it, i'll fix those issues. struct{} is indeed more efficient, thats why I used it.

[nhooyr]

@nsf why are get_candidates_from_decl and get_candidates_from_set methods of auto_complete_context. They don't use auto_complete_context. Should I make get_import_candidates a method as well then?

[nsf]

Because it came out of my OOP damaged brain. Yes you can make it a method, or a function. Doesn't matter.

[nhooyr]

@nsf All I have left to do are completing vendoring and gb. or should that be in another PR? I'll work on the rest of it tomorrow, I gotta do some homework now.

And I'm still not sure about the trailing / on directories, it did seem useful.

[nhooyr]

Yea after thinking about it a bit more, and using it, I think its worth adding the trailing /. its not very hard to get used to and its useful.

[nhooyr]

Ah screw it, i'm gonna just do it recursively, I agree with you, I think it'll be much better. LiteIDE actually does it recursively as well.

[nhooyr]

Alright, its recursive now. its not slow at all. i'm so confused now why I didn't like it when I first implemented it like this, sigh. Much better now...

[nsf]

Okay, I'm merging it, I think it's in good enough shape to be merged in.

[nsf]

It definitely works with godit and with vim out of the box. My own sublime text 3 plugin fails to handle it properly. Because it ignores returned partial length and just goes back to last word. Will see if I can fix it. Also in emacs company-mode doesn't work at all in string literals for some reason.

Oh, I see: https://github.com/nsf/gocode/blob/master/emacs-company/company-go.el#L191

I guess we'll have to remove that line maybe one day.

[nsf]

@nhooyr Thanks for the contribution. It's a nice addition to gocode.

[dominikh]

It also seems to be somewhat crash-happy:

2016/03/09 20:11:06 Go project path: sandbox/foo
2016/03/09 20:11:06 Got autocompletion request for '/home/dominikh/prj/src/sandbox/foo/foo.go'
2016/03/09 20:11:06 Cursor at: 24
2016/03/09 20:11:06 -------------------------------------------------------
package main

import (
    #
)
2016/03/09 20:11:06 -------------------------------------------------------
2016/03/09 20:11:06 Error parsing input file (outer block):
2016/03/09 20:11:06  4:2: expected 'STRING', found ';'
panic: runtime error: slice bounds out of range
1(runtime.call32): /usr/lib/go/src/runtime/asm_amd64.s:472
2(runtime.gopanic): /usr/lib/go/src/runtime/panic.go:426
3(runtime.panicslice): /usr/lib/go/src/runtime/panic.go:21
4(main.collect_package_imports): /home/dominikh/prj/src/github.com/nsf/gocode/declcache.go:34
5(main.(*auto_complete_file).process_data): /home/dominikh/prj/src/github.com/nsf/gocode/autocompletefile.go:76
6(main.(*auto_complete_context).apropos): /home/dominikh/prj/src/github.com/nsf/gocode/autocompletecontext.go:293
7(main.server_auto_complete): /home/dominikh/prj/src/github.com/nsf/gocode/server.go:179
8(main.(*RPC).RPC_auto_complete): /home/dominikh/prj/src/github.com/nsf/gocode/rpc.go:26
9(runtime.call64): /usr/lib/go/src/runtime/asm_amd64.s:473
10(reflect.Value.call): /usr/lib/go/src/reflect/value.go:435
11(reflect.Value.Call): /usr/lib/go/src/reflect/value.go:303
12(net/rpc.(*service).call): /usr/lib/go/src/net/rpc/server.go:383
13(runtime.goexit): /usr/lib/go/src/runtime/asm_amd64.s:1998

[nsf]

@dominikh Judging by the stack trace, it probably existed for years there.

[nsf]

@dominikh fixed

[nhooyr]

@nsf you're welcome