#+TITLE: GO contribution layer for Spacemacs

[[file:img/go.png]]

* Table of Contents                                                   :TOC@4:
 - [[#description][Description]]
 - [[#install][Install]]
     - [[#pre-requisites][Pre-requisites]]
     - [[#layer][Layer]]
 - [[#working-with-go][Working with Go]]
     - [[#go-commands-start-with-m][Go commands (start with =m=):]]
     - [[#go-oracle][Go Oracle]]

* Description

This layer adds extensive support for go.

Features:
- gofmt on file save
- Auto-completion using [[https://github.com/nsf/gocode/tree/master/emacs][go-autocomplete]]
- Source analysis using [[http://golang.org/s/oracle-user-manual][go-oracle]]

* Install

** Pre-requisites

You will need gocode:

#+BEGIN_SRC sh
  go get -u github.com/nsf/gocode
#+END_SRC

Make sure that =gocode= executable is in your PATH.

** Layer

To use this contribution add it to your =~/.spacemacs=

#+BEGIN_SRC emacs-lisp
  (setq-default dotspacemacs-configuration-layers '(go))
#+END_SRC

* Working with Go

** Go commands (start with =m=):
| Key Binding | Description                                               |
|-------------+-----------------------------------------------------------|
| ~SPC m d p~ | godoc at point                                            |
| ~SPC m i g~ | goto imports                                              |
| ~SPC m i a~ | add import                                                |
| ~SPC m i r~ | remove unused import                                      |
| ~SPC m p b~ | go-play buffer                                            |
| ~SPC m p r~ | go-play region                                            |
| ~SPC m p d~ | download go-play snippet                                  |
| ~SPC m t p~ | run "go test" for the current package                     |
| ~SPC m g a~ | jump to matching test file or back from test to code file |
| ~SPC m g g~ | go jump to definition                                     |


** Go Oracle

| Key Binding | Description                                                |
|-------------+------------------------------------------------------------|
| ~SPC m o o~ | go-oracle set analysis scope                               |
| ~SPC m o <~ | go-oracle show possible callers                            |
| ~SPC m o >~ | go-oracle show call targets                                |
| ~SPC m o c~ | go-oracle show channel sends/receives                      |
| ~SPC m o d~ | go-oracle show definition                                  |
| ~SPC m o f~ | go-oracle show free variables                              |
| ~SPC m o g~ | go-oracle show callgraph                                   |
| ~SPC m o i~ | go-oracle show implements relation                         |
| ~SPC m o p~ | go-oracle show what the select expression points to        |
| ~SPC m o r~ | go-oracle show all references to object                    |
| ~SPC m o s~ | go-oracle show callstack                                   |
| ~SPC m o t~ | go-oracle describe selected syntax, kind, type and methods |