Add nth-prime exercise (#137)

* Add nth-prime exercise

resolves #136

* Test NthPrime.prime

* reformat nth-prime config.json

config.json

@@ -400,6 +400,14 @@
         "prerequisites": [],
         "difficulty": 4
       },
+      {
+        "slug": "nth-prime",
+        "name": "Nth Prime",
+        "uuid": "b904e358-d446-41b2-a168-0be20a4c9df8",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 4
+      },
       {
         "slug": "robot-simulator",
         "name": "Robot Simulator",

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

@@ -0,0 +1,7 @@
+# Instructions
+
+Given a number n, determine what the nth prime is.
+
+By listing the first six prime numbers: 2, 3, 5, 7, 11, and 13, we can see that the 6th prime is 13.
+
+If your language provides methods in the standard library to deal with prime numbers, pretend they don't exist and implement them yourself.

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

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "keiravillekode"
+  ],
+  "files": {
+    "solution": [
+      "nth-prime.wren"
+    ],
+    "test": [
+      "nth-prime.spec.wren"
+    ],
+    "example": [
+      ".meta/proof.ci.wren"
+    ]
+  },
+  "blurb": "Given a number n, determine what the nth prime is.",
+  "source": "A variation on Problem 7 at Project Euler",
+  "source_url": "https://projecteuler.net/problem=7"
+}

exercises/practice/nth-prime/.meta/proof.ci.wren

@@ -0,0 +1,43 @@
+class NthPrime {
+  static prime(number) {
+    if (number == 0) {
+      Fiber.abort("there is no zeroth prime")
+    }
+
+    // Special case for the first two primes.
+    if (number <= 2) {
+      return number + 1
+    }
+    var remaining = number - 2
+
+    // candidate is never a multiple of 2 or 3.
+    var candidate = 5
+    var step = 2
+    while (true) {
+      if (isPrime(candidate)) {
+        remaining = remaining - 1
+        if (remaining == 0) {
+          return candidate
+        }
+      }
+      candidate = candidate + step
+      step = 6 - step
+    }
+  }
+
+  // candidate must not be a multiple of 2 or 3.
+  static isPrime(candidate) {
+    var limit = candidate.sqrt
+
+    var factor = 5
+    var step = 2
+    while (factor <= limit) {
+      if (candidate % factor == 0) {
+        return false
+      }
+      factor = factor + step
+      step = 6 - step
+    }
+    return true
+  }
+}

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

@@ -0,0 +1,25 @@
+# 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.
+
+[75c65189-8aef-471a-81de-0a90c728160c]
+description = "first prime"
+
+[2c38804c-295f-4701-b728-56dea34fd1a0]
+description = "second prime"
+
+[56692534-781e-4e8c-b1f9-3e82c1640259]
+description = "sixth prime"
+
+[fce1e979-0edb-412d-93aa-2c744e8f50ff]
+description = "big prime"
+
+[bd0a9eae-6df7-485b-a144-80e13c7d55b2]
+description = "there is no zeroth prime"

exercises/practice/nth-prime/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2023 Exercism
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

exercises/practice/nth-prime/nth-prime.spec.wren

@@ -0,0 +1,28 @@
+import "./nth-prime" for NthPrime
+import "wren-testie/testie" for Testie, Expect
+
+Testie.test("NthPrime.prime()") { |do, skip|
+  do.test("first prime") {
+    Expect.value(NthPrime.prime(1)).toEqual(2)
+  }
+
+  skip.test("second prime") {
+    Expect.value(NthPrime.prime(2)).toEqual(3)
+  }
+
+  skip.test("third prime") {
+    Expect.value(NthPrime.prime(3)).toEqual(5)
+  }
+
+  skip.test("sixth prime") {
+    Expect.value(NthPrime.prime(6)).toEqual(13)
+  }
+
+  skip.test("big prime") {
+    Expect.value(NthPrime.prime(10001)).toEqual(104743)
+  }
+
+  Expect.that {
+    NthPrime.prime(0)
+  }.abortsWith("there is no zeroth prime")
+}

exercises/practice/nth-prime/nth-prime.wren

@@ -0,0 +1,5 @@
+class NthPrime {
+  static prime(number) {
+    Fiber.abort("Remove this statement and implement this function")
+  }
+}

exercises/practice/nth-prime/package.wren

@@ -0,0 +1,14 @@
+import "wren-package" for WrenPackage, Dependency
+import "os" for Process
+
+class Package is WrenPackage {
+  construct new() {}
+  name { "exercism/nth-prime" }
+  dependencies {
+    return [
+      Dependency.new("wren-testie", "0.3.0", "https://github.com/joshgoebel/wren-testie.git")
+    ]
+  }
+}
+
+Package.new().default()