Robe is a code assistance tool that uses a Ruby REPL subprocess with your application or gem code loaded, to provide information about loaded classes and modules, and where each method is defined.
Generally, you'll want to start with
If there's no Ruby console running, most interactive commands provided
by Robe will offer to launch it automatically.
The exceptions are code completion and eldoc, which only work if the
server is already running. To launch it, type
As you change the code in your project, you'll want to update the
running process. To load the current file, type C-c C-l
ruby-load-file), see inf-ruby
for more commands. When you're working on a Rails project, you can
type C-c C-k instead to reload the whole environment at once.
- Jump to method definition
- Jump to
superor a constructor called at point
- Jump to a module/class/constant definition
- Display method documentation
- Display information about method called at point using ElDoc
- Method and constant name completion
- Jumping and completion for instance and local variable names, using simple regexp search in the current file
To see the available commands, type M-x describe-package RET robe RET.
When performing one of the commands defined here, we either need to narrow the method name at point down to a specific method in a specific module, or enumerate the possible method names or constants allowed at point (for code completion).
To do that, we look at the contents of the buffer, and the context at point: in which method it is, of which class, and if it's in singleton class context. Then we look at the method call at point.
If the method call target is implicit (there's no target or the method
super), or the call target is obvious (
then we first try to look for the definition in the inheritance
hierarchy of the target class. Otherwise, or if the initial search
yields no result, scan all defined classes and modules.
Depending on the command, if the result is ambiguous, you're either prompted to resolve the ambiguity manually, or the results are merged together.
Set up MELPA if you haven't already, then type M-x package-install RET robe RET.
In the init file:
(add-hook 'ruby-mode-hook 'robe-mode)
pry-doc>= 0.6.0 (for stdlib docs on MRI; optional)
Note that if your project is using
Bundler, the dependencies have to be added to the
(eval-after-load 'company '(push 'company-robe company-backends))
(add-hook 'robe-mode-hook 'ac-robe-setup)
Both of the above work only when the connection to the Ruby subprocess has been established. To do that, either use one of the core Robe commands, or type M-x robe-start.
Built-in completion (triggered with C-M-i) is also supported, no extra setup required.
Integration with rvm.el
rvm.el may not have activated the
correct project Ruby before
Either manually run M-x rvm-activate-corresponding-ruby
before starting Robe, or advise
inf-ruby-console-auto to activate
(advice-add 'inf-ruby-console-auto :before #'rvm-activate-corresponding-ruby)
- Tested in Emacs 24.4+, with Ruby 1.9.3-2.6, on GNU/Linux.
- Essential features work with JRuby, though the startup is longer.
- Mostly works on MS Windows, with minor glitches.
enh-ruby-modeis not recommended (it breaks the detection of the current context, see #47 and enhanced-ruby-mode#96).
- We can't jump to methods defined in C (such as most of the core classes).
To read their docs, install
pry-docor add it to your Gemfile.
- We can't jump to lazily defined methods, such as
ActiveRecordmethods, before they've been called. This is treatable, but low priority.
- Jumping to methods defined with
Module#delegatejust brings us to the place where
delegateis called, which is accurate, but often less than useful.
- To work on several projects in the same Emacs session, you'll have
to create the Ruby console for each project after the first one
M-x inf-ruby-console-auto. Otherwise, the first one will be used for all Ruby files, with suboptimal results.
- We may get the context wrong for code inside a block if the method
it's passed to uses
- For methods defined through macros, optionally jump to where the macro was called, instead of its definition?
- Apropos search for classes and methods.
- Type inference.
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with GNU Emacs; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.