# 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 There are two different methods of getting set up to run the tests with Objective-C: - Create an Xcode project with a test target which will run the tests. - Use the ruby gem `objc` as a test runner utility. Both are described in more detail here: http://exercism.io/languages/objective-c ### Submitting Exercises When submitting an exercise, make sure your solution file is in the same directory as the test code. The submit command will look something like: ```shell exercism submit /objective-c/etl/Etl.m ``` You can find the Exercism workspace by running `exercism debug` and looking for the line beginning with Workspace. ## 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.