# 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.

## Setup

Check out [Exercism Help](http://exercism.io/languages/lisp) for instructions to
get started writing Common Lisp. That page will explain how to install and setup
a Lisp implementation and how to run the tests.

## Formatting

While Common Lisp doesn't care about indentation and layout of code,
nor whether you use spaces or tabs, this is an important consideration
for submissions to exercism.io. Excercism.io's code widget cannot
handle mixing of tab and space characters well so using only spaces is recommended to make
the code more readable to the human reviewers. Please review your
editors settings on how to accomplish this. Below are instructions for
popular editors for Common Lisp.

### VIM

Use the following commands to ensure VIM uses only spaces for
indentation:

```vimscript
:set tabstop=2
:set shiftwidth=2
:set expandtab
```

(or as a oneliner `:set tabstop=2 shiftwidth=2 expandtab`). This can
be added to your `~/.vimrc` file to use it all the time.

### Emacs

Emacs is very well suited for editing Common Lisp and has many
powerful add-on packages available. The only thing that one needs to
do with a stock emacs to make it work well with exercism.io is to
evaluate the following code:

`(setq indent-tab-mode nil)`

This can be placed in your `~/.emacs` (or `~/.emacs.d/init.el`) in
order to have it set whenever Emacs is launched.

One suggested add-on for Emacs and Common Lisp is
[SLIME](https://github.com/slime/slime) which offers tight integration
with the REPL; making iterative coding and testing very easy.

## 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.