Avatar of paulfioravanti

paulfioravanti's solution

to Two Fer in the Elm Track

Published at Jun 18 2019 · 0 comments
Instructions
Test suite
Solution

Two-fer or 2-fer is short for two for one. One for you and one for me.

Given a name, return a string with the message:

One for X, one for me.

Where X is the given name.

However, if the name is missing, return the string:

One for you, one for me.

Here are some examples:

Name String to return
Alice One for Alice, one for me.
Bob One for Bob, one for me.
One for you, one for me.
Zaphod One for Zaphod, one for me.

Elm Installation

Refer to the Installing Elm page for information about installing elm.

Writing the Code

The first time you start an exercise, you'll need to ensure you have the appropriate dependencies installed. Thankfully, Elm makes that easy for you and will install dependencies when you try to run tests or build the code.

Execute the tests with:

$ elm-test

Automatically run tests again when you save changes:

$ elm-test --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

https://github.com/exercism/problem-specifications/issues/757

Submitting Incomplete Solutions

It is possible to submit an incomplete solution so you can see how others have completed the exercise.

Tests.elm

module Tests exposing (tests)

import Expect
import String
import Test exposing (..)
import TwoFer exposing (twoFer)


tests : Test
tests =
    describe "Two-fer"
        [ test "No name given" <|
            \() ->
                Expect.equal "One for you, one for me." (twoFer Nothing)
        , skip <|
            test "A name given" <|
                \() ->
                    Expect.equal "One for Alice, one for me." (twoFer (Just "Alice"))
        , skip <|
            test "Another name given" <|
                \() ->
                    Expect.equal "One for Bob, one for me." (twoFer (Just "Bob"))
        ]
module TwoFer exposing (twoFer)


twoFer : Maybe String -> String
twoFer name =
    let
        companion =
            name
                |> Maybe.withDefault "you"
    in
    "One for " ++ companion ++ ", one for me."

Community comments

Find this solution interesting? Ask the author a question to learn more.

What can you learn from this solution?

A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.

Here are some questions to help you reflect on this solution and learn the most from it.

  • What compromises have been made?
  • Are there new concepts here that you could read more about to improve your understanding?