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#!/bin/bash
mkdir -p tmp
rm tmp/run.js
elm-make test/TwelveToneTest.elm --output tmp/run.js
node tmp/run.js

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import ElmTest exposing (..)

tests : Test
tests =
  suite "Chapter 9: Etudes, Op. 3: Iteration, Rows and Sets"
  [
    test "noteToPc" (assertEqual 7 (noteToPc 55))
  ]

main =

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module TwelveTone exposing (noteToPc)

type alias Note = Int
type alias Pc = Int

noteToPc : Note -> Pc
noteToPc note =
  note % 12

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import ElmTest exposing (..)
import TwelveTone exposing (..)

tests : Test
tests =
  suite "Chapter 9: Etudes, Op. 3: Iteration, Rows and Sets"
  [
    test "noteToPc" (assertEqual 7 (noteToPc 55))
  ]

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Success! Compiled 1 module.
Successfully generated tmp/run.js
  1 suites run, containing 1 tests
  All tests passed

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test "listToPcs" (assertEqual [7,10,2,6] (listToPcs [55,58,62,66]))

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import List exposing (map)

...
listToPcs : List(Note) -> List Pc
listToPcs notes =
  map noteToPc notes

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test "normalizedPcs" (assertEqual [0,3,7,11] (normalizedPcs [55,58,62,66]))

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import List exposing (map, head)

...
normalizedPcs : List(Note) -> List Pc
normalizedPcs notes =
  let
    first = head notes
  in
    map (\note -> noteToPc (note - first)) notes

danigb

-- TYPE MISMATCH ------------------------------------------ ./src/TwelveTone.elm

The right argument of (-) is causing a type mismatch.

22|                             note - first)
                                       ^^^^^
(-) is expecting the right argument to be a:

    number