Created Array<CSV.Column>.seralize() method

Sources/CSV/CSVSeralizer.swift

@@ -0,0 +1,35 @@
+import Foundation
+import Bits
+
+extension Array where Element == CSV.Column {
+    func seralize() -> Data {
+        guard let count = self.first?.fields.count else {
+            return self.map { $0.header.data }.joined(separator: .comma)
+        }
+
+        var index = 0
+        var data: [Data] = [self.map { $0.header.data }.joined(separator: .comma)]
+        
+        while index < count {
+            data.append(self.map { ($0.fields[index] ?? "").data }.joined(separator: .comma))
+            index += 1
+        }
+        
+        return data.joined(separator: .newLine)
+    }
+}
+
+extension String {
+    var data: Data {
+        return Data(self.utf8)
+    }
+}
+
+extension Array where Element == Data {
+    func joined(separator: UInt8) -> Element {
+        return self.reduce(into: Data()) { data, subsequence in
+            if data.count > 0 { data.append(separator) }
+            data.append(contentsOf: subsequence)
+        }
+    }
+}

Tests/CSVTests/CSVTests.swift

@@ -1,3 +1,4 @@
+import Bits
 import XCTest
 @testable import CSV
 
@@ -42,9 +43,29 @@ class CSVTests: XCTestCase {
         XCTAssertEqual(fielders[0], Fielder(playerID: "abercda01", yearID: 1871, teamID: "TRO"))
     }
     
+    func testCSVColumnSeralization()throws {
+        let url = URL(string: "file:/Users/calebkleveter/Development/Fielding.csv")!
+        let data = try Data(contentsOf: url)
+        let parsed: [CSV.Column] = CSV.parse(data)
+        let _ = parsed.seralize()
+    }
+    
+    func testCSVColumnSeralizationSpeed()throws {
+        let url = URL(string: "file:/Users/calebkleveter/Development/Fielding.csv")!
+        let data = try Data(contentsOf: url)
+        let parsed: [CSV.Column] = CSV.parse(data)
+        
+        measure {
+            _ = parsed.seralize()
+        }
+    }
+    
     static var allTests = [
         ("testSpeed", testSpeed),
-        ("testRowSpeed", testRowSpeed)
+        ("testRowSpeed", testRowSpeed),
+        ("testCSVDecode", testCSVDecode),
+        ("testCSVColumnSeralization", testCSVColumnSeralization),
+        ("testCSVColumnSeralizationSpeed", testCSVColumnSeralizationSpeed)
     ]
 }