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                    -- The Erlang Development Tool Suite --

## License ##
Copyright (C) 2012 by Thomas Järvstrand, Håkan Nilsson

EDTS is licensed under the Lesser Gnu General Public License. See COPYING.LESSER
for details.

## Introduction ##

The Erlang Development Tool Suite (EDTS) is a package of useful development
tools for working with the Erlang programming language in Emacs. It bundles a
number of useful external packages, together with specialized Erlang plugins for
them, and its own features to create a complete and efficient development
environment that is easy to set up.

Currently EDTS provides:
- A snazzy erlang shell wrapper with syntax highlighting and auto-completion.
- In-buffer flymake-like compilation
- In-buffer xref checks
- Rudimentary project support
- Code navigation.
- Auto-completion, using auto-complete-mode
- Auto-highlighting, using auto-highlight-mode
- Convenient access to Erlang documentation
- In-buffer running of unit tests

In the works:
- Dialyzer integration
- A nice interface to the erlang debugger

For more information, hit M-x describe-minor-mode RET edts-mode RET.

## Getting started ##

- Requirements:
  - Emacs 23.3 or later (24.2 recommended)

- First of all, ensure your environment is setup correctly:
  - If you're not using Linux, setup Erlang mode according to the instructions
    here: http://www.erlang.org/doc/apps/tools/erlang_mode_chapter.html.
  - Make sure your code is compiled with the debug_info option set.

- Get the Erlang documentation (optional).

  The Erlang man-pages are assumed to be located in the man-directory of your
  erlang installation's root-directory. If you don't know where this is, you can
  find out by entering something like "readlink -f `which erl`" in a terminal.
  You'll see something like "/usr/lib/erlang/bin/erl" in which case
  "/usr/lib/erlang" would be your erlang root-dir. This is the usual place to
  install documentation when using tools like eg. aptitude.

  Alternatively, you can download your distribution's man-pages from:
  http://www.erlang.org/download.html

  Unpack and point edts' doc-root to the man-directory inside by adapting the
  following example and putting it in your .emacs:
  (edts-man-set-root "/home/my-user/doc/otp_doc_man_R15B02")

- Get EDTS:

  $git clone git://github.com/tjarvstrand/edts.git
  $cd edts
  $make

- Make sure EDTS is loaded and started in your .emacs:

  (add-to-list 'load-path "<path-to-edts-repo>")
  (require 'edts-start)

- Configure your projects. EDTS projects are stored in the variable
  `edts-projects'. `edts-projects' is a list of projects, where each project is
  an association list. The properties should all be strings, except lib-dirs
  which is a list of strings. The ones that can be set for each project are:

  root          - The top level directory of where you have your project
                  contents. This is the only required field.
  name          - The name of the project. Defaults to the last component
                  of the project root-directory (eg a root set to "~/src/p"
                  would yield "p" as the project name if not explicitly set.
  node-sname    - The erlang sname that the project's erlang node should
                  have. It should contain only the part before the @-sign and
                  defaults to same name as the project.
  lib-dirs      - A list of paths (relative to the project's root) where the
                  project's code is located. All subdirectories of lib-dirs are
                  assumed to be otp-applications. Defaults to '("lib").
  start-command - A custom command that EDTS should execute to start the
                  project's Erlang node. If this is set, the command must set
                  the node's sname to be the same as the value specified in the
                  project's node-sname. The command must also not set the
                  erlang cookie to anything other than the default
                  ~/.erlang.cookie.
  otp-path      - The path to any custom OTP-version to use for the project. You
                  only have to set this if the project uses a different OTP-
                  release than the one that comes first in your `exec-path'. The
                  OTP-release's bin-directory will be added to the head of the
                  exec-path and the PATH environment variable when starting the
                  project node.

  Example:
  (setq edts-projects
      '(( ;; My basic project
         (root       . "~/src/simple_stuff"))
        ( ;; My awesome project.
         (name       . "awesome_stuff")
         (root       . "~/src/awesome_stuff")
         (node-sname . "awesome")
         (otp-path   . "~/otp/r15b02"
         (start-command . "./start-being-awesome.sh"))
        ( ;; My other project.
         (name       . "other_stuff")
         (root       . "~/src/other_stuff")
         (node-sname . "not_as_awesome")
         (lib-dirs   . ("lib" "test")))))

That should be all it takes. If it's not, please report any issues on github.

## How it works ##

Once set up, EDTS will automatically fire up it's own Erlang node when you start
your Emacs. Once you open the first file that is located inside one of your
projects, then EDTS will automatically fire up the corresponding project node
and initiate communication between the EDTS-node and the project-node. If a node
with the same name as the project's node is already registered with the Erlang
port mapper daemon (epmd), then EDTS will initiate communication with that node
instead. The EDTS node exposes a REST-interface (using webmachine) through which
emacs can then communicate with the project node.

## EDTS and Distel ##

EDTS is meant to be a able to replace Distel but only provides part of the most
commonly used of Distel's features, specifically the equivalents of
erl-find-module, erl-find-source-under-point, erl-who-calls and
erl-refactor-subfunction. As far as I know, those are the only Distel features
that 98% of people use, but if there is anything from Distel that you are
missing in EDTS, please let me know.

If you are using EDTS, please remove Distel from your configuration, since
running both can create some confusion.

## Known Issues ##

Some users are experiencing serious performance issues with the auto-completion
during the first use after startup. This is usually solved by typing C-g a
couple (two or three, it seems to vary) of times when Emacs "hangs" the first
time. It is most likely caused by a bug in the emacs c-code that affects
the auto-complete package. If you experience these issues, it's recommended to
switch to emacs 24.2 where the problem is fixed [1], but if the problems
persist, any help in debugging the issue would be appreciated since I have
never myself been able to reproduce it.

When killing some buffers, Emacs 23 decides to move point to (point-max) in a
seemingly completely unrelated buffer. This will sometimes happen as an effect
of EDTS' after-save-hook. The issue does not exist in Emacs 24.

[1] auto-complete/auto-complete#153