mirror of
https://github.com/correl/elm.git
synced 2024-12-23 03:00:08 +00:00
6151955420
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
81 lines
2.3 KiB
Markdown
81 lines
2.3 KiB
Markdown
# Etl
|
|
|
|
We are going to do the `Transform` step of an Extract-Transform-Load.
|
|
|
|
### ETL
|
|
Extract-Transform-Load (ETL) is a fancy way of saying, "We have some crufty, legacy data over in this system, and now we need it in this shiny new system over here, so
|
|
we're going to migrate this."
|
|
|
|
(Typically, this is followed by, "We're only going to need to run this
|
|
once." That's then typically followed by much forehead slapping and
|
|
moaning about how stupid we could possibly be.)
|
|
|
|
### The goal
|
|
We're going to extract some scrabble scores from a legacy system.
|
|
|
|
The old system stored a list of letters per score:
|
|
|
|
- 1 point: "A", "E", "I", "O", "U", "L", "N", "R", "S", "T",
|
|
- 2 points: "D", "G",
|
|
- 3 points: "B", "C", "M", "P",
|
|
- 4 points: "F", "H", "V", "W", "Y",
|
|
- 5 points: "K",
|
|
- 8 points: "J", "X",
|
|
- 10 points: "Q", "Z",
|
|
|
|
The shiny new scrabble system instead stores the score per letter, which
|
|
makes it much faster and easier to calculate the score for a word. It
|
|
also stores the letters in lower-case regardless of the case of the
|
|
input letters:
|
|
|
|
- "a" is worth 1 point.
|
|
- "b" is worth 3 points.
|
|
- "c" is worth 3 points.
|
|
- "d" is worth 2 points.
|
|
- Etc.
|
|
|
|
Your mission, should you choose to accept it, is to transform the legacy data
|
|
format to the shiny new format.
|
|
|
|
### Notes
|
|
|
|
A final note about scoring, Scrabble is played around the world in a
|
|
variety of languages, each with its own unique scoring table. For
|
|
example, an "E" is scored at 2 in the Māori-language version of the
|
|
game while being scored at 4 in the Hawaiian-language version.
|
|
|
|
## 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
|
|
|
|
The Jumpstart Lab team [http://jumpstartlab.com](http://jumpstartlab.com)
|
|
|
|
## Submitting Incomplete Solutions
|
|
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
|