[prime-factors] Implementation

config.json

@@ -481,6 +481,15 @@
         "prerequisites": [],
         "difficulty": 1,
         "topics": []
+      },
+      {
+        "slug": "prime-factors",
+        "name": "Prime Factors",
+        "uuid": "042178b2-2a80-4dff-ade2-4fae71b23076",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 1,
+        "topics": []
       }      
     ]
   },

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/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "habere-et-dispertire"
+  ],
+  "files": {
+    "solution": [
+      "PrimeFactors.rakumod"
+    ],
+    "test": [
+      "prime-factors.rakutest"
+    ],
+    "example": [
+      ".meta/solutions/PrimeFactors.rakumod"
+    ]
+  },
+  "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/solutions/PrimeFactors.rakumod

@@ -0,0 +1,10 @@
+unit module PrimeFactors;
+
+multi factors ( 1, | ) is export          { Empty   };
+multi factors ( $n where $n.is-prime, | ) { $n.List };
+multi factors ( $n, @primes = ( 2 .. * ).grep: *.is-prime ) {
+  given $n %% @primes.head {
+    when *.so { @primes.head, factors( $n div @primes.head, @primes      ).Slip }
+    default   {               factors( $n,                  @primes.skip )      }
+  }
+}

exercises/practice/prime-factors/.meta/solutions/prime-factors.rakutest

@@ -0,0 +1 @@
+../../prime-factors.rakutest

exercises/practice/prime-factors/.meta/template-data.yaml

@@ -0,0 +1,26 @@
+properties:
+  factors:
+    test: |-
+      sprintf(q:to/END/, (%case<input><value>, %case<expected>.List<>, %case<description>).map(*.raku));
+      cmp-ok(
+          factors(%s),
+          "~~",
+          %s,
+          %s,
+      );
+      END
+
+unit: module
+example: |-
+  multi factors ( 1, | ) is export          { Empty   };
+  multi factors ( $n where $n.is-prime, | ) { $n.List };
+  multi factors ( $n, @primes = ( 2 .. * ).grep: *.is-prime ) {
+    given $n %% @primes.head {
+      when *.so { @primes.head, factors( $n div @primes.head, @primes      ).Slip }
+      default   {               factors( $n,                  @primes.skip )      }
+    }
+  }
+
+stub: |-
+  sub factors ( $number ) is export {
+  }

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/PrimeFactors.rakumod

@@ -0,0 +1,4 @@
+unit module PrimeFactors;
+
+sub factors ( $number ) is export {
+}

exercises/practice/prime-factors/prime-factors.rakutest

@@ -0,0 +1,90 @@
+#!/usr/bin/env raku
+use Test;
+use lib $?FILE.IO.dirname;
+use PrimeFactors;
+
+cmp-ok( # begin: 924fc966-a8f5-4288-82f2-6b9224819ccd
+    factors(1),
+    "~~",
+    (),
+    "no factors",
+); # end: 924fc966-a8f5-4288-82f2-6b9224819ccd
+
+cmp-ok( # begin: 17e30670-b105-4305-af53-ddde182cb6ad
+    factors(2),
+    "~~",
+    (2,),
+    "prime number",
+); # end: 17e30670-b105-4305-af53-ddde182cb6ad
+
+cmp-ok( # begin: 238d57c8-4c12-42ef-af34-ae4929f94789
+    factors(3),
+    "~~",
+    (3,),
+    "another prime number",
+); # end: 238d57c8-4c12-42ef-af34-ae4929f94789
+
+cmp-ok( # begin: f59b8350-a180-495a-8fb1-1712fbee1158
+    factors(9),
+    "~~",
+    (3, 3),
+    "square of a prime",
+); # end: f59b8350-a180-495a-8fb1-1712fbee1158
+
+cmp-ok( # begin: 756949d3-3158-4e3d-91f2-c4f9f043ee70
+    factors(4),
+    "~~",
+    (2, 2),
+    "product of first prime",
+); # end: 756949d3-3158-4e3d-91f2-c4f9f043ee70
+
+cmp-ok( # begin: bc8c113f-9580-4516-8669-c5fc29512ceb
+    factors(8),
+    "~~",
+    (2, 2, 2),
+    "cube of a prime",
+); # end: bc8c113f-9580-4516-8669-c5fc29512ceb
+
+cmp-ok( # begin: 7d6a3300-a4cb-4065-bd33-0ced1de6cb44
+    factors(27),
+    "~~",
+    (3, 3, 3),
+    "product of second prime",
+); # end: 7d6a3300-a4cb-4065-bd33-0ced1de6cb44
+
+cmp-ok( # begin: 073ac0b2-c915-4362-929d-fc45f7b9a9e4
+    factors(625),
+    "~~",
+    (5, 5, 5, 5),
+    "product of third prime",
+); # end: 073ac0b2-c915-4362-929d-fc45f7b9a9e4
+
+cmp-ok( # begin: 6e0e4912-7fb6-47f3-a9ad-dbcd79340c75
+    factors(6),
+    "~~",
+    (2, 3),
+    "product of first and second prime",
+); # end: 6e0e4912-7fb6-47f3-a9ad-dbcd79340c75
+
+cmp-ok( # begin: 00485cd3-a3fe-4fbe-a64a-a4308fc1f870
+    factors(12),
+    "~~",
+    (2, 2, 3),
+    "product of primes and non-primes",
+); # end: 00485cd3-a3fe-4fbe-a64a-a4308fc1f870
+
+cmp-ok( # begin: 02251d54-3ca1-4a9b-85e1-b38f4b0ccb91
+    factors(901255),
+    "~~",
+    (5, 17, 23, 461),
+    "product of primes",
+); # end: 02251d54-3ca1-4a9b-85e1-b38f4b0ccb91
+
+cmp-ok( # begin: 070cf8dc-e202-4285-aa37-8d775c9cd473
+    factors(93819012551),
+    "~~",
+    (11, 9539, 894119),
+    "factors include a large prime",
+); # end: 070cf8dc-e202-4285-aa37-8d775c9cd473
+
+done-testing;