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# acolburn's solution

## to ETL in the Delphi Pascal Track

Published at Jan 12 2021 · 0 comments
Instructions
Test suite
Solution

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.

## Testing

In order to run the tests for this track, you will need to install DUnitX. Please see the installation instructions for more information.

If Delphi is properly installed, and `*.dpr` file types have been associated with Delphi, then double clicking the supplied `*.dpr` file will start Delphi and load the exercise/project. `control + F9` is the keyboard shortcut to compile the project or pressing `F9` will compile and run the project.

Alternatively you may opt to start Delphi and load your project via. the `File` drop down menu.

### When Questions Come Up

We monitor the Pascal-Delphi support room on gitter.im to help you with any questions that might arise.

### Submitting Exercises

Note that, when trying to submit an exercise, make sure the exercise file you're submitting is in the `exercism/delphi/<exerciseName>` directory.

For example, if you're submitting `ubob.pas` for the Bob exercise, the submit command would be something like `exercism submit <path_to_exercism_dir>/delphi/bob/ubob.pas`.

## Source

The Jumpstart Lab team http://jumpstartlab.com

## Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you may request help from a mentor.

### uETLTests.pas

``````unit uETLTests;

interface
uses
System.Generics.Collections, DUnitX.TestFramework;

const
CanonicalVersion = '1.0.0.1';

type

[TestFixture]
testETL = class(TObject)
private
procedure CompareDictionaries(Expected, Actual: TDictionary<String, integer>);
public
[Test]
procedure Validate_CompareDictionaries;

[Test]
//    [Ignore('Comment the "[Ignore]" statement to run the test')]
procedure A_single_letter;

[Test]
[Ignore]
procedure Single_score_with_multiple_letters;

[Test]
[Ignore]
procedure Multiple_scores_with_multiple_letters;

[Test]
[Ignore]
procedure Multiple_scores_with_differing_numbers_of_letters;
end;

implementation
uses SysUtils, uETL;

procedure testETL.CompareDictionaries(Expected, Actual: TDictionary<String, Integer>);
var expectedPair: TPair<string, Integer>;
begin
Assert.AreEqual(Expected.Count, Actual.Count);
for expectedPair in Expected do
begin
Assert.IsTrue(Actual.ContainsKey(expectedPair.Key));
Assert.AreEqual(expectedPair.Value, Actual[expectedPair.Key]);
end;
end;

procedure testETL.Validate_CompareDictionaries;
var expected, actual: TDictionary<String, integer>;
begin
expected := TDictionary<String, integer>.Create;

actual := TDictionary<String, Integer>.create(expected);

CompareDictionaries(expected, actual);
end;

procedure testETL.A_single_letter;
var aList: TList<string>;
old: TDictionary<integer, TList<string>>;
expected: TDictionary<string, integer>;
begin
aList := TList<string>.Create;
old := TDictionary<integer, TList<string>>.Create;

expected := TDictionary<string, integer>.Create;

CompareDictionaries(expected, ETL.Transform(old));
end;

procedure testETL.Single_score_with_multiple_letters;
var aList: TList<string>;
old: TDictionary<integer, TList<string>>;
expected: TDictionary<string, integer>;
begin
aList := TList<string>.create;
old := TDictionary<integer, TList<string>>.Create;

expected := TDictionary<string, integer>.Create;

CompareDictionaries(expected, ETL.Transform(old));
end;

procedure testETL.Multiple_scores_with_multiple_letters;
var aList: TList<string>;
old: TDictionary<integer, TList<string>>;
expected: TDictionary<string, integer>;
begin
aList := TList<string>.Create;
old := TDictionary<integer, TList<string>>.Create;
aList := TList<string>.Create;

expected := TDictionary<string, integer>.Create;

CompareDictionaries(expected, ETL.Transform(old));
end;

procedure testETL.Multiple_scores_with_differing_numbers_of_letters;
var aList: TList<string>;
old: TDictionary<integer, TList<string>>;
expected: TDictionary<string, integer>;
begin
aList := TList<string>.Create;
old := TDictionary<integer, TList<string>>.Create;

aList := TList<string>.Create;

aList := TList<string>.Create;

aList := TList<string>.Create;

aList := TList<string>.Create;

aList := TList<string>.Create;

aList := TList<string>.Create;

expected := TDictionary<string, integer>.Create;

CompareDictionaries(expected, ETL.Transform(old));
end;

initialization
TDUnitX.RegisterTestFixture(testETL);
end.``````
``````unit uETL;

interface

uses
System.Generics.Collections;

type
ETL = class
public
class function Transform(old: TDictionary < integer, TList < string >> )
: TDictionary<string, integer>;
end;

implementation

uses Vcl.Dialogs, System.SysUtils;

{ ETL }

class function ETL.Transform(old: TDictionary < integer, TList < string >> )
: TDictionary<string, integer>;
var
item: TPair<integer, TList<string>>;
letters: TList<string>;
letter: string;
begin
// in result dictionary, each key is letter, value is its points
result := TDictionary<string, integer>.Create;
// in old dictionary, each item's key is points, value is TList of letters
for item in old do
begin
letters := item.Value;
for letter in letters do
end;

end;

end.``````