From d7bd1decc9c985988992ecbba4c0c07918d48f37 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oscar=20Bystr=C3=B6m=20Ericsson?= <oscbyspro@protonmail.com>
Date: Fri, 24 Nov 2023 10:45:32 +0100
Subject: [PATCH] Get first one thousand or one million primes option (#114).

---
 Sources/NBKCoreKit/Models/NBKPrimeSieve.swift | 11 +++++++
 .../Models/NBKPrimeSieve.swift                | 20 +++++++++----
 .../Models/NBKPrimeSieve.swift                | 30 ++++++++++++++++---
 3 files changed, 51 insertions(+), 10 deletions(-)

diff --git a/Sources/NBKCoreKit/Models/NBKPrimeSieve.swift b/Sources/NBKCoreKit/Models/NBKPrimeSieve.swift
index 4fd02746..4255abaa 100644
--- a/Sources/NBKCoreKit/Models/NBKPrimeSieve.swift
+++ b/Sources/NBKCoreKit/Models/NBKPrimeSieve.swift
@@ -30,12 +30,23 @@
     // MARK: Initializers
     //=------------------------------------------------------------------------=
     
+    /// Generates a list of the first `count` number of primes.
+    public init(first count: PrimeCountLimit) {
+        self.init(through: count.rawValue)
+    }
+    
     /// Generates a list of all primes from zero through `limit`.
     public init(through limit: UInt) {
         self._limit = limit
         self._elements = []
         Self.primesByEratosthenes(through: limit, appending: &self._elements)
     }
+    
+    //*========================================================================*
+    // MARK: * Prime Count Limit
+    //*========================================================================*
+    
+    public enum PrimeCountLimit: UInt { case thousand = 7919, million = 15485863 }
 }
 
 //=----------------------------------------------------------------------------=
diff --git a/Tests/NBKCoreKitBenchmarks/Models/NBKPrimeSieve.swift b/Tests/NBKCoreKitBenchmarks/Models/NBKPrimeSieve.swift
index 08fce6de..cf59ff34 100644
--- a/Tests/NBKCoreKitBenchmarks/Models/NBKPrimeSieve.swift
+++ b/Tests/NBKCoreKitBenchmarks/Models/NBKPrimeSieve.swift
@@ -25,37 +25,37 @@ final class NBKPrimeSieveBenchmarks: XCTestCase {
     //=------------------------------------------------------------------------=
     
     func test1000X1() {
-        for _ in 0 ... 1000 {
+        for _ in 0 ..< 1000 {
             NBK.blackHole(T(through: 1))
         }
     }    
     
     func test1000X10() {
-        for _ in 0 ... 1000 {
+        for _ in 0 ..< 1000 {
             NBK.blackHole(T(through: 10))
         }
     }
     
     func test1000X100() {
-        for _ in 0 ... 1000 {
+        for _ in 0 ..< 1000 {
             NBK.blackHole(T(through: 100))
         }
     }
     
     func test1000X1000() {
-        for _ in 0 ... 1000 {
+        for _ in 0 ..< 1000 {
             NBK.blackHole(T(through: 1000))
         }
     }
     
     func test1000X10000() {
-        for _ in 0 ... 1000 {
+        for _ in 0 ..< 1000 {
             NBK.blackHole(T(through: 10000))
         }
     }
     
     func test1000X100000() {
-        for _ in 0 ... 1000 {
+        for _ in 0 ..< 1000 {
             NBK.blackHole(T(through: 100000))
         }
     }
@@ -64,6 +64,14 @@ final class NBKPrimeSieveBenchmarks: XCTestCase {
     // MARK: Tests x No Loop
     //=------------------------------------------------------------------------=
     
+    func testNoLoopFirst1000() {
+        NBK.blackHole(T(first: .thousand))
+    }
+    
+    func testNoLoopFirst1000000() {
+        NBK.blackHole(T(first: .million))
+    }
+    
     func testNoLoop1E6() {
         NBK.blackHole(T(through: 1000000))
     }
diff --git a/Tests/NBKCoreKitTests/Models/NBKPrimeSieve.swift b/Tests/NBKCoreKitTests/Models/NBKPrimeSieve.swift
index 9b480ba3..1963a138 100644
--- a/Tests/NBKCoreKitTests/Models/NBKPrimeSieve.swift
+++ b/Tests/NBKCoreKitTests/Models/NBKPrimeSieve.swift
@@ -22,7 +22,6 @@ final class NBKPrimeSieveTests: XCTestCase {
     // MARK: State
     //=------------------------------------------------------------------------=
     
-    // - TODO: Replace these with a 1-million-primes text file.
     static let primes: [UInt] = [
     0002, 0003, 0005, 0007, 0011, 0013, 0017, 0019, 0023, 0029,
     0031, 0037, 0041, 0043, 0047, 0053, 0059, 0061, 0067, 0071,
@@ -171,13 +170,36 @@ final class NBKPrimeSieveTests: XCTestCase {
         check(through: 10000, expectation: Self.primes.prefix(1229))
     }
     
+    func testPrimesThroughPrimeCountLimit() {
+        brr: do {
+            let result = T(first: .thousand)
+            XCTAssertEqual(result.elements.count,  1000)
+            XCTAssertEqual(result.elements.last!,  7919)
+            XCTAssertEqual(result.elements.last!,  result.limit)
+            check(result, limit: Self.primes[999], elements: Self.primes[...999])
+        }
+        
+        #if !DEBUG // fast in RELEASE, slow in DEBUG
+        brr: do {
+            let result = T(first: .million)
+            XCTAssertEqual(result.elements.count, 01000000)
+            XCTAssertEqual(result.elements.last!, 15485863)
+            XCTAssertEqual(result.elements.last!, result.limit)
+        }
+        #endif
+    }
+    
     //=------------------------------------------------------------------------=
     // MARK: Assertions
     //=------------------------------------------------------------------------=
     
     func check(through limit: UInt, expectation: ArraySlice<UInt>, file: StaticString = #file, line: UInt = #line) {
-        let result = T(through: limit)
-        XCTAssertEqual(result.limit,  limit, file:  file, line: line)
-        XCTAssertEqual(result.elements[...], expectation, file: file, line: line)
+        check(T(through: limit), limit: limit, elements: expectation, file: file, line: line)
+    }
+    
+    func check(_ sieve: T, limit: UInt, elements: ArraySlice<UInt>, file: StaticString = #file, line: UInt = #line) {
+        XCTAssertEqual(sieve.limit,  limit, file: file, line: line)
+        XCTAssertEqual(sieve.elements[...], (elements), file: file,  line: line)
+        XCTAssertLessThanOrEqual(sieve.elements.last ?? 0000, limit, file: file, line: line)
     }
 }