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We are working towards making exercises stand-alone. That is to say: no more generating READMEs on the fly. This will give maintainers more control over each individual exercise README, and it will also make some of the backend logic for delivering exercises simpler. The README template uses the Go text/template package, and the default templates generate the same READMEs as we have been generating on the fly. See the documentation in [regenerating exercise readmes][regenerate-docs] for details. The READMEs can be generated at any time using a new 'generate' command in configlet. This command has not yet landed in master or been released, but can be built from source in the generate-readmes branch on [configlet][]. [configlet]: https://github.com/exercism/configlet [regenerate-docs]: https://github.com/exercism/docs/blob/master/maintaining-a-track/regenerating-exercise-readmes.md |
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| .. | ||
| tests | ||
| elm-package.json | ||
| package.json | ||
| README.md | ||
| RunLengthEncoding.elm | ||
| RunLengthEncoding.example.elm | ||
| RunLengthEncodingPropertyChecks.elm | ||
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 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.
$ npm install
Execute the tests with:
$ npm test
Automatically run tests again when you save changes:
$ 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
Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.