misc/emacs: Greatly improve go-mode for Emacs.

The original go-mode is plagued with odd behaviour, lack of
behaviour typical to modes in Emacs and bugs.

This change rewrites great parts of go-mode (basically only
keeping the gofmt and godoc functions).

Additionally it adds new features such as manipulating package
imports.

For more information please see
https://groups.google.com/group/golang-nuts/browse_frm/thread/3a9d6dae3369c0b5/1efe65e2f7afb190

Fixes #3618.
Fixes #4240.
Fixes #4322.
Fixes #4671.
Fixes #4726.

R=golang-dev, fullung, sameer, cw, arthur, proppy, adonovan, rsc, bradfitz
CC=golang-dev
https://golang.org/cl/7314113

misc/emacs/go-mode-load.el

-;;; go-mode-load.el --- Major mode for the Go programming language
-
+;;; go-mode-load.el --- automatically extracted autoloads
 ;;; Commentary:
 
 ;; To install go-mode, add the following lines to your .emacs file:
 ;;   (add-to-list 'load-path "PATH CONTAINING go-mode-load.el" t)
 ;;   (require 'go-mode-load)
+;;
 ;; After this, go-mode will be used for files ending in '.go'.
-
+;;
 ;; To compile go-mode from the command line, run the following
 ;;   emacs -batch -f batch-byte-compile go-mode.el
-
+;;
 ;; See go-mode.el for documentation.
-
-;;; Code:
-
+;;
 ;; To update this file, evaluate the following form
 ;;   (let ((generated-autoload-file buffer-file-name)) (update-file-autoloads "go-mode.el"))
 
+;;; Code:
+
 
-;;;### (autoloads (gofmt-before-save gofmt go-mode) "go-mode" "go-mode.el"
-;;;;;;  (19917 17808))
+;;;### (autoloads (go-download-play godoc gofmt-before-save go-mode)
+;;;;;;  "go-mode" "go-mode.el" (20767 50749))
 ;;; Generated autoloads from go-mode.el
 
 (autoload 'go-mode "go-mode" "\
 Major mode for editing Go source text.
 
-This provides basic syntax highlighting for keywords, built-ins,
-functions, and some types.  It also provides indentation that is
-\(almost) identical to gofmt.
+This mode provides (not just) basic editing capabilities for
+working with Go code. It offers almost complete syntax
+highlighting, indentation that is almost identical to gofmt,
+proper parsing of the buffer content to allow features such as
+navigation by function, manipulation of comments or detection of
+strings.
+
+Additionally to these core features, it offers various features to
+help with writing Go code. You can directly run buffer content
+through gofmt, read godoc documentation from within Emacs, modify
+and clean up the list of package imports or interact with the
+Playground (uploading and downloading pastes).
+
+The following extra functions are defined:
+
+- `gofmt'
+- `godoc'
+- `go-import-add'
+- `go-remove-unused-imports'
+- `go-goto-imports'
+- `go-play-buffer' and `go-play-region'
+- `go-download-play'
+
+If you want to automatically run `gofmt' before saving a file,
+add the following hook to your emacs configuration:
+
+\(add-hook 'before-save-hook 'gofmt-before-save)
+
+If you're looking for even more integration with Go, namely
+on-the-fly syntax checking, auto-completion and snippets, it is
+recommended to look at goflymake
+\(https://github.com/dougm/goflymake), gocode
+\(https://github.com/nsf/gocode) and yasnippet-go
+\(https://github.com/dominikh/yasnippet-go)
 
 \(fn)" t nil)
 
-(add-to-list 'auto-mode-alist (cons "\\.go$" #'go-mode))
-
-(autoload 'gofmt "go-mode" "\
-Pipe the current buffer through the external tool `gofmt`.
-Replace the current buffer on success; display errors on failure.
-
-\(fn)" t nil)
+(add-to-list 'auto-mode-alist (cons "\\.go\\'" 'go-mode))
 
 (autoload 'gofmt-before-save "go-mode" "\
 Add this to .emacs to run gofmt on the current buffer when saving:
- (add-hook 'before-save-hook #'gofmt-before-save)
+ (add-hook 'before-save-hook 'gofmt-before-save).
+
+Note that this will cause go-mode to get loaded the first time
+you save any file, kind of defeating the point of autoloading.
 
 \(fn)" t nil)
 
-;;;***
+(autoload 'godoc "go-mode" "\
+Show go documentation for a query, much like M-x man.
+
+\(fn QUERY)" t nil)
 
+(autoload 'go-download-play "go-mode" "\
+Downloads a paste from the playground and inserts it in a Go
+buffer. Tries to look for a URL at point.
+
+\(fn URL)" t nil)
+
+;;;***
+
 (provide 'go-mode-load)
+;; Local Variables:
+;; version-control: never
+;; no-byte-compile: t
+;; no-update-autoloads: t
+;; coding: utf-8
+;; End:
+;;; go-mode-load.el ends here