# 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"
```

If the string contains any whitespace, it should be passed through unchanged:

```
"aabc dddef"  ->  "2abc 3def"
```

For simplicity, you can assume that the unencoded string will only contain
the letters A through Z (either lower or uppercase) and whitespace.

## Running tests

Execute the tests with:

```bash
$ elixir bob_test.exs
```

(Replace `bob_test.exs` with the name of the test file.)


### Pending tests

In the test suites, all but the first test have been skipped.

Once you get a test passing, you can unskip the next one by
commenting out the relevant `@tag :pending` with a `#` symbol.

For example:

```elixir
# @tag :pending
test "shouting" do
  assert Bob.hey("WATCH OUT!") == "Whoa, chill out!"
end
```

Or, you can enable all the tests by commenting out the
`ExUnit.configure` line in the test suite.

```elixir
# ExUnit.configure exclude: :pending, trace: true
```

For more detailed information about the Elixir track, please
see the [help page](http://exercism.io/languages/elixir).

## Source

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

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