any sequence, no black

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name="marc",
-    version="22.5.0",
+    version="22.5.1",
     url="https://github.com/maxhumber/marc",
     description="Markov chain generator",
     long_description=long_description,
@@ -20,11 +20,6 @@
     ],
     packages=[""],
     package_dir={"": "python/src"},
-    extras_require={
-        "dev": [
-            "black>=22.3.0",
-        ],
-    },
     python_requires=">=3.9",
     setup_requires=["setuptools>=62.1.0"],
 )

swift/Sources/Marc/MarkovChain.swift

@@ -13,9 +13,9 @@ public class MarkovChain<Element: Hashable> {
     /// ```
     /// let chain = MarkovChain(["R", "P", "S"])
     /// ```
-    public init(_ sequence: [Element]) {
+    public init<S: Sequence>(_ sequence: S) where S.Element == Element {
         // reducing per: https://developer.apple.com/documentation/swift/dictionary/3127177-reduce
-        store = zip(sequence, sequence[1...]).reduce(into: Store()) { result, pair in
+        store = zip(sequence, sequence.dropFirst(1)).reduce(into: Store()) { result, pair in
             result[pair.0, default: [:]][pair.1, default: 0] += 1
         }
     }

swift/Tests/MarcTests/MarcTests.swift

@@ -4,10 +4,15 @@ import XCTest
 final class MarcTests: XCTestCase {
     var chain: MarkovChain<String>!
 
+    typealias PerfStore = [Int: [Int: Int]]
+    let perfSeq = (0..<10_000).map { _ in Int.random(in: 1...5) }
+    var perfStore: PerfStore!
+
     override func setUp() {
         let playerThrows = "RRRSRSRRPRPSPPRPSSSPRSPSPRRRPSSPRRPRSRPRPSSSPRPRPSSRPSRPRSSPRP"
         let sequence = playerThrows.map { String($0) }
         chain = MarkovChain(sequence)
+        perfStore = PerfStore()
     }
 
     func testSubscript() {
@@ -28,4 +33,12 @@ final class MarcTests: XCTestCase {
         let contains = ["R", "P", "S"].contains(next)
         XCTAssertTrue(contains)
     }
+
+    func testStorePerformance() {
+       measure {
+           perfStore = zip(perfSeq, perfSeq.dropFirst(1)).reduce(into: PerfStore()) { result, pair in
+               result[pair.0, default: [:]][pair.1, default: 0] += 1
+           }
+        }
+    }
 }