# Common Lisp

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Exercism exercises in Lisp


## Contributing to the Common Lisp Track

### Contributing Guide

Please be familiar with the
[contributing guide](https://github.com/exercism/x-api/blob/master/CONTRIBUTING.md#the-exercise-data)
in the x-api repository. This describes how all the language tracks
are put together, as well as details about the common metadata, and
high-level information about contributing to existing problems and
adding new problems.

### Issues

Feel free to file any issues at
https://github.com/exercism/common-lisp/issues for problems of any size.
Feel free to report typographical errors or poor wording for example.
You can greatly help improve the quality of the exercises by filing
reports of invalid solutions that pass tests or of valid solutions
that fail tests

### Development setup

Direct contributions to the Common Lisp code in xLisp are always welcome.
Refer to [the Getting Started Guide](http://exercism.io/languages/common-lisp) for the
Common Lisp track to get your environment set up if needed.

New exercises or changes to existing ones can be submitted via a pull
request. You will need a GitHub account and you will need to fork
`exercism/xlisp` to your account. See
[GitHub Help](https://help.github.com/articles/fork-a-repo/) if you
are unfamiliar with the process.

#### Development Guidelines

##### Setting up the development environment.

All changes will be built under several implementations via the
[TravisCI build](https://travis-ci.org/exercism/common-lisp) so it advisable
to be able to run at least some of those same builds locally before
submitting the changes.

A contributor will need to install:

* [Roswell](https://github.com/roswell/roswell)
* [QuickLisp](https://www.quicklisp.org/beta/)
* and a few Lisp implementations.


###### Roswell

Instructions for installing Roswell can be found in
its
[README](https://github.com/roswell/roswell#installation-dependency--usage).

###### Lisp Implementations

It is beyond the scope of this document to describe how to install
different Lisp implementations. Please find those instructions on
those implementations' websites.

After installing Lisp implementations. Check that Roswell can see them by
running `ros list installed`.

###### QuickLisp

Although [QuickLisp](https://www.quicklisp.org/beta/) is
required, Roswell will install and configure it for you, by default.

##### Creating a new exercise.

All new exercise submissions should contain not only the test file,
but the stub of the "production code" (containing the `defpackage` and
`in-package` forms), and a file `example.lisp` which contains an
example implementation. The "production code" and `example.lisp` may
also include an empty function declaration for the functions under
test.

##### Building & Testing

Before submitting a new exercise please ensure that it passes the
Travis build.  This build will run all exercises on many Common Lisp
implementations. To run the build yourself on your implementation load
`bin/xlisp-test.lisp` and then evaluate `(xlisp-test:full-build)`.

If Roswell is installed then running all the tests for one
implementation can be done with (this will return with a non-zero
error code if there are problems):

    ros run -l 'bin/xlisp-test.lisp' -e '(xlisp-test:travis-build)' -q

##### Style Guidelines

The example implementation should use nothing outside of the Common
Lisp specification. It should be well designed and not too clever.
(Save the clever implementation for your submission on Exercism.io.)