git clone https://github.com/purescript-contrib/purescript-book.git

$ ls purescript-book/
CNAME  CONTRIBUTING.md  README.md  book.toml  deploy_key.enc  exercises  scripts  text

#!/usr/bin/env bash

# This script automatically resets exercises so they are ready to be solved.
#  - Removes lines with a note to delete them.
#  - Moves the no-peeking directory outside of the compilation path.

# For all chapters
for d in exercises/*; do
  # if directory (excludes LICENSE file)
  if [ -d $d ]; then
    perl -ni -e 'print if !/Note to reader: Delete this line/' $d/test/Main.purs
  fi
  # if there's a no-peeking directory
  if [ -d $d/test/no-peeking ]; then
    mv $d/test/no-peeking $d/no-peeking
  fi
done

$ perl --help

Usage: perl [switches] [--] [programfile] [arguments]
[...省略]
  -i[extension]     edit <> files in place (makes backup if extension supplied)
[...省略]
  -n                assume "while (<>) { ... }" loop around program

print if !/Note to reader: Delete this line/

$ cat hoge.txt
hoge
foo
foo
hoge
bar
hoge
bar
$ perl -ni -e 'print if !/hoge/' hoge.txt
$ cat hoge.txt
foo
foo
bar
bar

if [ -d $d/test/no-peeking ]; then
    mv $d/test/no-peeking $d/no-peeking
fi

$ ./scripts/resetSolutions.sh

#!/usr/bin/env bash

# This script removes all code anchors to improve readability

# All .purs files in the exercises directories (excluding hidden files)
ALL_PURS=$(find exercises \( ! -regex '.*/\..*' \) -type f -name '*.purs')

for f in $ALL_PURS; do
  # Delete lines starting with an '-- ANCHOR' comment
  perl -ni -e 'print if !/^\s*-- ANCHOR/' $f
done

$ ./scripts/removeAnchors.sh

git add .
git commit --all --message "Exercises ready to be solved"

$ git add .
$ git commit -a -m "練習問題を解く準備完了"

$ cd exercises/chapter2/
$ spago test
[info] Installing 54 dependencies.
...省略

Warning 1 of 25:

  in module Control.MonadZero
  at .spago/control/v5.0.0/src/Control/MonadZero.purs:48:1 - 48:43 (line 48, column 1 - line 48, column 43)

    A custom warning occurred while solving type class constraints:

      'MonadZero' is deprecated, use 'Monad' and 'Alternative' constraints instead


  in value declaration monadZeroArray

  See https://github.com/purescript/documentation/blob/master/errors/UserDefinedWarning.md for more information,
  or to contribute content related to this warning.

[info] Build succeeded.
[warn] None of your project files import modules from some projects that are in the direct dependencies of your project.
These dependencies are unused. To fix this warning, remove the following packages from the list of dependencies in your config:
- integers
- math
→ Suite: Euler - Sum of Multiples
  ✓ Passed: below 10
  ✓ Passed: below 1000

All 2 tests passed! 🎉
[info] Tests succeeded.

ns = range 0 999

multiples = filter (\n -> mod n 3 == 0 || mod n 5 == 0) ns

ns n = range 0 (n - 1)

multiples n = filter (\n -> mod n 3 == 0 || mod n 5 == 0) (ns n)

module Test.Main where

import Prelude
import Test.MySolutions
import Effect (Effect)
import Euler (answer)
import Test.Unit (suite, test)
import Test.Unit.Assert as Assert
import Test.Unit.Main (runTest)

main :: Effect Unit
main = do
  runTest do
    suite "Euler - Sum of Multiples" do
      test "below 10" do
        Assert.equal 23 (answer 10)
      test "below 1000" do
        Assert.equal 233168 (answer 1000)
    {-  Move this block comment starting point to enable more tests
    suite "diagonal" do
      test "3 4 5" do
        Assert.equal 5.0 (diagonal 3.0 4.0)
      test "5 12 13" do
        Assert.equal 13.0 (diagonal 5.0 12.0)
    suite "circleArea" do
      test "radius 1" do
        Assert.equal 3.141592653589793 (circleArea 1.0)
      test "radius 3" do
        Assert.equal 28.274333882308138 (circleArea 3.0)
    suite "leftoverCents" do
      test "23" do
        Assert.equal 23 (leftoverCents 23)
      test "456" do
        Assert.equal 56 (leftoverCents 456)
      test "-789" do
        Assert.equal (-89) (leftoverCents (-789))

-}

Move this block comment starting point to enable more tests

module Test.MySolutions where

import Prelude

-    {-  Move this block comment starting point to enable more tests
    suite "diagonal" do
      test "3 4 5" do
        Assert.equal 5.0 (diagonal 3.0 4.0)
      test "5 12 13" do
        Assert.equal 13.0 (diagonal 5.0 12.0)
+    {-  Move this block comment starting point to enable more tests

$ pwd
~/purescript-book/exercises/chapter2

$ spago test
Compiling Test.Main
Error found:
in module Test.Main
at test/Main.purs:21:27 - 21:35 (line 21, column 27 - line 21, column 35)

  Unknown value diagonal


See https://github.com/purescript/documentation/blob/master/errors/UnknownName.md for more information,
or to contribute content related to this error.


[error] Failed to build.

import Math (sqrt)

diagonal w h = sqrt (w * w + h)

$ spago test
Compiling Test.MySolutions
Compiling Test.Main
Warning 1 of 3:

  in module Test.MySolutions
  at test/MySolutions.purs:6:1 - 6:32 (line 6, column 1 - line 6, column 32)

    No type declaration was provided for the top-level declaration of diagonal.
    It is good practice to provide type declarations as a form of documentation.
    The inferred type of diagonal was:

      Number -> Number -> Number


  in value declaration diagonal

  See https://github.com/purescript/documentation/blob/master/errors/MissingTypeDeclaration.md for more information,
  or to contribute content related to this warning.

Warning 2 of 3:

  in module Test.Main
  at test/Main.purs:3:1 - 3:15 (line 3, column 1 - line 3, column 15)

    Module Prelude has unspecified imports, consider using the explicit form:

      import Prelude (Unit, discard)



  See https://github.com/purescript/documentation/blob/master/errors/ImplicitImport.md for more information,
  or to contribute content related to this warning.

Warning 3 of 3:

  in module Test.Main
  at test/Main.purs:4:1 - 4:24 (line 4, column 1 - line 4, column 24)

    Module Test.MySolutions has unspecified imports, consider using the explicit form:

      import Test.MySolutions (diagonal)



  See https://github.com/purescript/documentation/blob/master/errors/ImplicitImport.md for more information,
  or to contribute content related to this warning.


[info] Build succeeded.
[warn] None of your project files import modules from some projects that are in the direct dependencies of your project.
These dependencies are unused. To fix this warning, remove the following packages from the list of dependencies in your config:
- integers
→ Suite: Euler - Sum of Multiples
  ✓ Passed: below 10
  ✓ Passed: below 1000
→ Suite: diagonal
  ☠ Failed: 3 4 5 because expected 5.0, got 3.605551275463989
  ☠ Failed: 5 12 13 because expected 13.0, got 6.082762530298219

2 tests failed:

In "diagonal":
  In "5 12 13":
    expected 13.0, got 6.082762530298219

In "diagonal":
  In "3 4 5":
    expected 5.0, got 3.605551275463989

[error] Tests failed: exit code: 1

diagonal w h = sqrt (w * w + h * h)

→ Suite: Euler - Sum of Multiples
  ✓ Passed: below 10
  ✓ Passed: below 1000
→ Suite: diagonal
  ✓ Passed: 3 4 5
  ✓ Passed: 5 12 13

All 4 tests passed! 🎉
[info] Tests succeeded.

    suite "circleArea" do
      test "radius 1" do
        Assert.equal 3.141592653589793 (circleArea 1.0)
      test "radius 3" do
        Assert.equal 28.274333882308138 (circleArea 3.0)

module Test.MySolutions where

import Prelude
-import Math (sqrt)
+import Math (sqrt, pi)

diagonal w h = sqrt (w * w + h * h)
+
+circleArea radius = pi * radius * radius

$ spago test
 :
→ Suite: circleArea
  ✓ Passed: radius 1
  ✓ Passed: radius 3

+leftoverCents n = rem n 100

+import Data.Int (rem)

$ spago test
 :
→ Suite: leftoverCents
  ✓ Passed: 23
  ✓ Passed: 456
  ✓ Passed: -789