elm/exercises/run-length-encoding/README.md

# Run Length Encoding

Implement run-length encoding and decoding.

Run-length encoding (RLE) is a simple form of data compression, where runs
(consecutive data elements) are replaced by just one data value and count.

For example we can represent the original 53 characters with only 13.

```
"WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWB"  ->  "12WB12W3B24WB"
```

RLE allows the original data to be perfectly reconstructed from
the compressed data, which makes it a lossless data compression.

```
"AABCCCDEEEE"  ->  "2AB3CD4E"  ->  "AABCCCDEEEE"
```

For simplicity, you can assume that the unencoded string will only contain
the letters A through Z (either lower or upper case) and whitespace. This way 
data to be encoded will never contain any numbers and numbers inside data to 
be decoded always represent the count for the following character.

## Elm Installation

Refer to the [Exercism help page](http://exercism.io/languages/elm) for Elm
installation and learning resources.

## Writing the Code

The first time you start an exercise, you'll need to ensure you have the
appropriate dependencies installed.

```bash
$ npm install
```

Execute the tests with:

```bash
$ npm test
```

Automatically run tests again when you save changes:

```bash
$ npm run watch
```

As you work your way through the test suite, be sure to remove the `skip <|`
calls from each test until you get them all passing!

## Source

Wikipedia [https://en.wikipedia.org/wiki/Run-length_encoding](https://en.wikipedia.org/wiki/Run-length_encoding)

## Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.