Implement exercise 'prime-factors'

config.json

@@ -68,6 +68,14 @@
         "prerequisites": [],
         "difficulty": 1
       },
+      {
+        "slug": "prime-factors",
+        "name": "Prime Factors",
+        "uuid": "9cc8f9a8-66c4-44e2-ad9d-c9ca4efa9dfc",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1
+      },
       {
         "slug": "resistor-color",
         "name": "Resistor Color",

config.yaml

@@ -71,6 +71,13 @@ exercises:
     prerequisites: []
     difficulty: 1
 
+  - slug: prime-factors
+    name: Prime Factors
+    uuid: 9cc8f9a8-66c4-44e2-ad9d-c9ca4efa9dfc
+    practices: []
+    prerequisites: []
+    difficulty: 1
+
   - slug: resistor-color
     name: Resistor Color
     uuid: edb17966-2a6c-47c8-ac65-d66b00deb97b

exercises/practice/prime-factors/.docs/instructions.md

@@ -0,0 +1,36 @@
+# Instructions
+
+Compute the prime factors of a given natural number.
+
+A prime number is only evenly divisible by itself and 1.
+
+Note that 1 is not a prime number.
+
+## Example
+
+What are the prime factors of 60?
+
+- Our first divisor is 2.
+  2 goes into 60, leaving 30.
+- 2 goes into 30, leaving 15.
+  - 2 doesn't go cleanly into 15.
+    So let's move on to our next divisor, 3.
+- 3 goes cleanly into 15, leaving 5.
+  - 3 does not go cleanly into 5.
+    The next possible factor is 4.
+  - 4 does not go cleanly into 5.
+    The next possible factor is 5.
+- 5 does go cleanly into 5.
+- We're left only with 1, so now, we're done.
+
+Our successful divisors in that computation represent the list of prime factors of 60: 2, 2, 3, and 5.
+
+You can check this yourself:
+
+```text
+2 * 2 * 3 * 5
+= 4 * 15
+= 60
+```
+
+Success!

exercises/practice/prime-factors/.meta/Makefile

@@ -0,0 +1,28 @@
+SHELL := bash
+
+BASE := $(shell pwd)
+
+export YS_VERSION := 0.1.80
+
+YS_LOCAL_PREFIX := ../../../../.local/v$(YS_VERSION)
+
+YS_LOCAL_BIN := $(YS_LOCAL_PREFIX)/bin
+
+YS_BIN := $(YS_LOCAL_BIN)/ys-$(YS_VERSION)
+
+TEST_FILE ?= $(wildcard *-test.ys)
+
+
+export PATH := $(YS_LOCAL_BIN):$(PATH)
+
+export YSPATH := $(BASE)
+
+
+default:
+
+test: $(YS_BIN)
+	prove -v $(TEST_FILE)
+
+$(YS_BIN):
+	curl -s https://yamlscript.org/install | \
+	  BIN=1 VERSION=$(YS_VERSION) PREFIX=$(YS_LOCAL_PREFIX) bash >/dev/null

exercises/practice/prime-factors/.meta/config.json

@@ -0,0 +1,22 @@
+{
+  "authors": [
+    "ingydotnet"
+  ],
+  "files": {
+    "solution": [
+      "prime-factors.ys"
+    ],
+    "test": [
+      "prime-factors-test.ys",
+      "GNUmakefile",
+      "Makefile",
+      ".yamlscript/exercism-ys-installer"
+    ],
+    "example": [
+      ".meta/prime-factors.ys"
+    ]
+  },
+  "blurb": "Compute the prime factors of a given natural number.",
+  "source": "The Prime Factors Kata by Uncle Bob",
+  "source_url": "https://web.archive.org/web/20221026171801/http://butunclebob.com/ArticleS.UncleBob.ThePrimeFactorsKata"
+}

exercises/practice/prime-factors/.meta/prime-factors-test.ys

@@ -0,0 +1,96 @@
+#!/usr/bin/env ys-0
+
+require ys::taptest: :all
+
+use: prime-factors
+
+test::
+- name: No factors
+  code: factors(1)
+  want: []
+  uuid: 924fc966-a8f5-4288-82f2-6b9224819ccd
+
+- name: Prime number
+  code: factors(2)
+  want:
+  - 2
+  uuid: 17e30670-b105-4305-af53-ddde182cb6ad
+
+- name: Another prime number
+  code: factors(3)
+  want:
+  - 3
+  uuid: 238d57c8-4c12-42ef-af34-ae4929f94789
+
+- name: Square of a prime
+  code: factors(9)
+  want:
+  - 3
+  - 3
+  uuid: f59b8350-a180-495a-8fb1-1712fbee1158
+
+- name: Product of first prime
+  code: factors(4)
+  want:
+  - 2
+  - 2
+  uuid: 756949d3-3158-4e3d-91f2-c4f9f043ee70
+
+- name: Cube of a prime
+  code: factors(8)
+  want:
+  - 2
+  - 2
+  - 2
+  uuid: bc8c113f-9580-4516-8669-c5fc29512ceb
+
+- name: Product of second prime
+  code: factors(27)
+  want:
+  - 3
+  - 3
+  - 3
+  uuid: 7d6a3300-a4cb-4065-bd33-0ced1de6cb44
+
+- name: Product of third prime
+  code: factors(625)
+  want:
+  - 5
+  - 5
+  - 5
+  - 5
+  uuid: 073ac0b2-c915-4362-929d-fc45f7b9a9e4
+
+- name: Product of first and second prime
+  code: factors(6)
+  want:
+  - 2
+  - 3
+  uuid: 6e0e4912-7fb6-47f3-a9ad-dbcd79340c75
+
+- name: Product of primes and non-primes
+  code: factors(12)
+  want:
+  - 2
+  - 2
+  - 3
+  uuid: 00485cd3-a3fe-4fbe-a64a-a4308fc1f870
+
+- name: Product of primes
+  code: factors(901255)
+  want:
+  - 5
+  - 17
+  - 23
+  - 461
+  uuid: 02251d54-3ca1-4a9b-85e1-b38f4b0ccb91
+
+- name: Factors include a large prime
+  code: factors(93819012551)
+  want:
+  - 11
+  - 9539
+  - 894119
+  uuid: 070cf8dc-e202-4285-aa37-8d775c9cd473
+
+done: 12

exercises/practice/prime-factors/.meta/prime-factors.ys

@@ -0,0 +1,8 @@
+!yamlscript/v0
+
+defn factors(value):
+  or _ []:
+    when value >= 2:
+      divisor =: range(2 (value / 2).++)
+        .filter(\((value % _) == 0)):first || value
+      into [divisor]: factors(quot(value divisor))

exercises/practice/prime-factors/.meta/tests.toml

@@ -0,0 +1,46 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[924fc966-a8f5-4288-82f2-6b9224819ccd]
+description = "no factors"
+
+[17e30670-b105-4305-af53-ddde182cb6ad]
+description = "prime number"
+
+[238d57c8-4c12-42ef-af34-ae4929f94789]
+description = "another prime number"
+
+[f59b8350-a180-495a-8fb1-1712fbee1158]
+description = "square of a prime"
+
+[756949d3-3158-4e3d-91f2-c4f9f043ee70]
+description = "product of first prime"
+
+[bc8c113f-9580-4516-8669-c5fc29512ceb]
+description = "cube of a prime"
+
+[7d6a3300-a4cb-4065-bd33-0ced1de6cb44]
+description = "product of second prime"
+
+[073ac0b2-c915-4362-929d-fc45f7b9a9e4]
+description = "product of third prime"
+
+[6e0e4912-7fb6-47f3-a9ad-dbcd79340c75]
+description = "product of first and second prime"
+
+[00485cd3-a3fe-4fbe-a64a-a4308fc1f870]
+description = "product of primes and non-primes"
+
+[02251d54-3ca1-4a9b-85e1-b38f4b0ccb91]
+description = "product of primes"
+
+[070cf8dc-e202-4285-aa37-8d775c9cd473]
+description = "factors include a large prime"

exercises/practice/prime-factors/.yamlscript/exercism-ys-installer

@@ -0,0 +1,127 @@
+#!/env/bin/env bash
+
+set -euo pipefail
+
+intro-prompt() (
+  cat <<...
+--------------------------------------------------------------------------------
+
+This YAMLScript Exercism exercise requires the YAMLScript version $version
+interpreter command file to be installed here:
+
+  $prefix/bin/ys
+
+You can install it by pressing Enter now, or by running this command:
+
+  $make install-ys
+
+This should only take a few seconds and you only need to do this once.
+Other exercises will use the same file.
+
+See https://yamlscript.org/doc/install/ for more YAMLScript installation info.
+
+--------------------------------------------------------------------------------
+
+Would you like to install the 'ys' file now?
+
+...
+
+  printf "Press Enter to install. Ctl-C to Quit."; read -r
+)
+
+main() {
+  setup "$@"
+
+  install-from-local
+
+  $auto && intro-prompt
+
+  installed || install-from-release || true
+  installed || install-from-build || true
+  installed ||
+    die "Installing '$installed' failed. Giving up." \
+        "Consider filing an issue at: $gh_issue_url"
+
+  echo
+  echo 'Success!'
+  echo "$installed is now installed."
+  echo
+}
+
+installed() {
+  [[ -f $installed ]]
+}
+
+install-from-local() {
+  local path
+  path=$(command -v "$ysfq") || true
+  if [[ -f $path ]]; then
+    mkdir -p "$bin"
+    cp "$path" "$bin"/
+    ln -fs "$ysfq" "$bin/ys-0"
+    ln -fs "$ysfq" "$bin/ys"
+    (installed && $auto) && exit
+    true
+  fi
+}
+
+install-from-release() (
+  set -x
+  curl -s https://yamlscript.org/install |
+    BIN=1 VERSION="$version" PREFIX="$prefix" bash
+)
+
+install-from-build() (
+  cat <<...
+
+The binary release installation failed.
+We can attempt to build and install $ysfq now.
+This can take from 1 to 5 minutes to complete.
+
+...
+
+  printf "Press Enter to install. Ctl-C to Quit."; read -r
+
+  [[ -d /tmp && -w /tmp ]] ||
+    die "Can't write to /tmp" \
+        'Giving up.'
+
+  set -x
+
+  rm -fr "$yamlscript_clone"
+
+  git clone --branch="$version" "$yamlscript_repo" "$yamlscript_clone"
+
+  "$make" -C "$yamlscript_clone/ys" install PREFIX="$prefix"
+)
+
+setup() {
+  version=$1
+  prefix=$2
+  make=$3
+  auto=false
+  [[ ${4-} ]] && auto=true
+
+  [[ $version =~ ^0\.1\.[0-9]+$ ]] ||
+    die "Invalid YS_VERSION '$version'"
+
+  bin=$prefix/bin
+  ysfq=ys-$version
+  installed=$bin/$ysfq
+
+  if installed; then
+    echo "'$installed' is already installed."
+    exit
+  fi
+
+  yamlscript_repo=https://github.com/yaml/yamlscript
+  yamlscript_clone=/tmp/yamlscript-exercism
+  gh_issue_url=https://github.com/exercism/yamlscript/issues
+}
+
+die() {
+  printf '%s\n' "$@" >&2
+  exit 1
+}
+
+main "$@"