# Contributing to Torch7 Core (torch7, nn, cutorch, cunn)

Thanks a lot! There are plenty of ways you can help!

Please take a moment to review this document in order to make the contribution
process easy and effective for everyone involved.

Following these guidelines helps to communicate that you respect the time of
the developers managing and developing this open source project. In return,
they should reciprocate that respect in addressing your issue or assessing
patches and features.


## Using the issue tracker

The [issue tracker](https://github.com/torch/nn/issues) is
the preferred channel for [bug reports](#bugs), [features requests](#features)
and [submitting pull requests](#pull-requests), but please respect the following
restrictions:

* Please **do not** use the issue tracker for personal support requests (use
  [mailing-list](http://groups.google.com/forum/#!forum/torch7)).

* Please **do not** open issues regarding the code in a torch package 
  outside the core. For example don't open issues about the 
  REPL in the nn issue tracker, use the trepl issue tracker for that.

<a name="bugs"></a>
## Bug reports

A bug is a _demonstrable problem_ that is caused by the code in the repository.
Good bug reports are extremely helpful - thank you!

Guidelines for bug reports:

1. **Use the GitHub issue search** &mdash; check if the issue has already been
   reported.

2. **Check if the issue has been fixed** &mdash; try to reproduce it using the
   latest `master` or development branch in the repository.

3. **Isolate the problem** &mdash; ideally create test case that is within reason,
   preferably within 100 lines of code.

A good bug report shouldn't leave others needing to chase you up for more
information. Please try to be as detailed as possible in your report. What is
your environment? What steps will reproduce the issue? What OS do you
experience the problem? What would you expect to be the outcome? All these
details will help people to fix any potential bugs.

<a name="features"></a>
## Feature requests

Feature requests are welcome to be filed. Torch is community-developed, 
the maintainers are not exclusive torch developers, so keep that in mind.
The purpose of feature requests is for others who are looking to implement
a feature are aware of the interest in the feature.


<a name="pull-requests"></a>
## Pull requests

Good pull requests - patches, improvements, new features - are a fantastic
help. They should remain focused in scope **and avoid containing unrelated
commits.**

**Please ask first** before embarking on any significant pull request (e.g.
implementing features, refactoring code, porting to a different language),
otherwise you risk spending a lot of time working on something that the
project's developers might not want to merge into the project.

Please adhere to the coding conventions used throughout a project (indentation,
accurate comments, etc.) and any other requirements (such as test coverage).

Adhering to the following this process is the best way to get your work
included in the project:

1. [Fork](https://help.github.com/articles/fork-a-repo) the project, clone your
   fork, and configure the remotes:

   ```bash
   # Clone your fork of the repo into the current directory
   git clone https://github.com/<your-username>/nn.git
   # Navigate to the newly cloned directory
   cd nn
   # Assign the original repo to a remote called "upstream"
   git remote add upstream https://github.com/torch/nn.git
   ```

2. If you cloned a while ago, get the latest changes from upstream:

   ```bash
   git checkout master
   git pull upstream master
   ```

3. Create a new topic branch (off the main project development branch) to
   contain your feature, change, or fix:

   ```bash
   git checkout -b <topic-branch-name>
   ```

4. Commit your changes in logical chunks. Please try to adhere to these [git commit
   message guidelines](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
   . Use Git's [interactive rebase](https://help.github.com/articles/about-git-rebase)
   feature to tidy up your commits before making them public. This helps us keep the 
   commit history in logical blocks and clean, as torch grows. 
   For example: 
     - If you are adding a new function or a module, keep the module + tests + doc 
       to a single commit unless logically warranted. 
     - If you are fixing a bug, keep the bugfix to a single commit unless logically warranted.

5. Locally merge (or rebase) the upstream development branch into your topic branch:

   ```bash
   git pull [--rebase] upstream master
   ```

6. Push your topic branch up to your fork:

   ```bash
   git push origin <topic-branch-name>
   ```

7. [Open a Pull Request](https://help.github.com/articles/using-pull-requests/)
    with a clear title and description.

**IMPORTANT**: By submitting a patch, you agree to allow the project owners to
license your work under the terms of the BSD License.

## Development workflow tips

* While you are changing lua files, one can simply symlink the cloned nn directory to ~/torch/install/share/lua/5.1/nn so that any change is reflected in the current install, without constantly having to do luarocks make rocks/*
* If you are changing C files, then, after every change, you run luarocks make rocks/*
* To test, you can just use: th -lnn -e "nn.test()"
