Remove development artifacts and add test improvements

- Remove compass artifact file
- Add new encoder test files for nested, parallel, and strategy testing

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: g-cqd

Sources/CSVCoder/Parsing/CSVParser.swift

@@ -0,0 +1,165 @@
+//
+//  CSVRowView.swift
+//  CSVCoder
+//
+//  A zero-copy view into a single CSV row within a raw UTF-8 buffer.
+//
+
+import Foundation
+
+// MARK: - CSVRowView
+
+/// A zero-copy view into a single CSV row within a raw UTF-8 buffer.
+///
+/// `CSVRowView` provides efficient access to field data without allocating copies.
+/// It stores byte offsets and lengths rather than string values, enabling
+/// high-performance parsing of large CSV files.
+///
+/// ## Thread Safety
+///
+/// `CSVRowView` is **not** `Sendable` because it references a borrowed buffer
+/// that must remain valid for the view's lifetime. Always use within the closure
+/// scope of ``CSVParser/parse(data:delimiter:body:)``.
+///
+/// ## Usage
+///
+/// ```swift
+/// CSVParser.parse(data: csvData) { parser in
+///     for row in parser {
+///         for i in 0..<row.count {
+///             if let value = row.string(at: i) {
+///                 print(value)
+///             }
+///         }
+///     }
+/// }
+/// ```
+///
+/// ## Performance Notes
+///
+/// - Field access via ``string(at:)`` is O(1) for unquoted fields
+/// - Quoted fields with escaped quotes (`""`) require O(n) unescaping
+/// - Use ``getBytes(at:)`` for maximum performance when UTF-8 bytes suffice
+public struct CSVRowView {
+    // MARK: Lifecycle
+
+    /// Creates a row view with the given buffer and field metadata.
+    public init(
+        buffer: UnsafeBufferPointer<UInt8>,
+        fieldStarts: [Int],
+        fieldLengths: [Int],
+        fieldQuoted: [Bool],
+        fieldHasEscapedQuote: [Bool],
+        hasUnterminatedQuote: Bool,
+        hasQuoteInUnquotedField: Bool,
+    ) {
+        self.buffer = buffer
+        self.fieldStarts = fieldStarts
+        self.fieldLengths = fieldLengths
+        self.fieldQuoted = fieldQuoted
+        self.fieldHasEscapedQuote = fieldHasEscapedQuote
+        self.hasUnterminatedQuote = hasUnterminatedQuote
+        self.hasQuoteInUnquotedField = hasQuoteInUnquotedField
+    }
+
+    // MARK: Public
+
+    /// Reference to the full buffer (owned elsewhere).
+    public let buffer: UnsafeBufferPointer<UInt8>
+
+    /// Offsets of field starts within the buffer.
+    public let fieldStarts: [Int]
+
+    /// Lengths of each field.
+    public let fieldLengths: [Int]
+
+    /// Whether each field was quoted (needs unescaping).
+    public let fieldQuoted: [Bool]
+
+    /// Whether each field contains escaped quotes ("" that need unescaping.
+    public let fieldHasEscapedQuote: [Bool]
+
+    /// Whether any field has an unterminated quote.
+    public let hasUnterminatedQuote: Bool
+
+    /// Whether any unquoted field contains a quote character (RFC 4180 violation).
+    public let hasQuoteInUnquotedField: Bool
+
+    /// The number of fields in this row.
+    public var count: Int { fieldStarts.count }
+
+    /// Returns the raw UTF-8 bytes for the field at the given index.
+    ///
+    /// This method provides zero-copy access to field data, useful when
+    /// you need to perform custom parsing or validation without allocating strings.
+    ///
+    /// - Parameter index: The zero-based field index.
+    /// - Returns: A buffer pointer to the field's UTF-8 bytes, or an empty buffer if out of bounds.
+    /// - Complexity: O(1)
+    ///
+    /// - Warning: The returned buffer is only valid while the parent `CSVParser`'s
+    ///   data remains in scope. Do not store the buffer beyond the parsing closure.
+    public func getBytes(at index: Int) -> UnsafeBufferPointer<UInt8> {
+        let start = fieldStarts[index]
+        let length = fieldLengths[index]
+        guard start + length <= buffer.count else { return UnsafeBufferPointer(start: nil, count: 0) }
+        return UnsafeBufferPointer(start: buffer.baseAddress?.advanced(by: start), count: length)
+    }
+
+    /// Decodes and returns the string value for the field at the given index.
+    ///
+    /// Handles RFC 4180 quote unescaping automatically:
+    /// - Quoted fields have outer quotes stripped
+    /// - Escaped quotes (`""`) are converted to single quotes (`"`)
+    ///
+    /// - Parameter index: The zero-based field index.
+    /// - Returns: The decoded string value, or `nil` if the index is out of bounds.
+    /// - Complexity: O(1) for unquoted fields; O(n) for quoted fields with escaped quotes.
+    public func string(at index: Int) -> String? {
+        string(at: index, encoding: .utf8)
+    }
+
+    /// Decodes and returns the string value for the field at the given index using the specified encoding.
+    ///
+    /// Handles RFC 4180 quote unescaping automatically:
+    /// - Quoted fields have outer quotes stripped
+    /// - Escaped quotes (`""`) are converted to single quotes (`"`)
+    ///
+    /// - Parameters:
+    ///   - index: The zero-based field index.
+    ///   - encoding: The string encoding to use for conversion. For best performance, use `.utf8`.
+    /// - Returns: The decoded string value, or `nil` if the index is out of bounds or conversion fails.
+    /// - Complexity: O(1) for unquoted UTF-8 fields; O(n) for quoted fields with escaped quotes or non-UTF-8 encodings.
+    public func string(at index: Int, encoding: String.Encoding) -> String? {
+        guard index < fieldStarts.count else { return nil }
+
+        let start = fieldStarts[index]
+        let length = fieldLengths[index]
+        let isQuoted = fieldQuoted[index]
+        let hasEscapedQuote = fieldHasEscapedQuote[index]
+
+        guard let base = buffer.baseAddress else { return nil }
+
+        let ptr = base.advanced(by: start)
+        let fieldBuffer = UnsafeBufferPointer(start: ptr, count: length)
+
+        // Fast path for UTF-8 (most common case)
+        if encoding == .utf8 {
+            if isQuoted, hasEscapedQuote {
+                // Use zero-allocation unescaper
+                return CSVUnescaper.unescape(buffer: fieldBuffer)
+            } else {
+                // No unescaping needed - direct decode
+                return String(decoding: fieldBuffer, as: UTF8.self)
+            }
+        }
+
+        // Non-UTF-8 encoding path (ASCII-compatible encodings like ISO-8859-1, Windows-1252)
+        if isQuoted, hasEscapedQuote {
+            return CSVUnescaper.unescape(buffer: fieldBuffer, encoding: encoding)
+        }
+
+        let data = Data(bytes: ptr, count: length)
+        return String(data: data, encoding: encoding)
+    }
+}

Sources/CSVCoder/Parsing/CSVRowView.swift

@@ -118,6 +118,7 @@ enum CSVUtilities {
              .windowsCP1253,
              .windowsCP1254:
             true
+
         case .unicode,
              .utf16,
              .utf16BigEndian,

Sources/CSVCoder/Utilities/CSVUtilities.swift

@@ -202,7 +202,26 @@ nonisolated func generateOrderCSV(rows: Int) -> String {
         let hasDiscount = i % 3 == 0
         let hasNotes = i % 5 == 0
         let hasShipDate = i % 2 == 0
-        csv += "ORD-\(String(format: "%08d", i)),\(1000 + i % 500),\"Customer \(i)\",customer\(i)@example.com,\(i % 1000),\"Product \(i % 100)\",\(1 + i % 10),\(Double(10 + i % 100)),\(hasDiscount ? "0.1" : ""),0.08,5.99,\(Double(10 + i % 100) * Double(1 + i % 10)),USD,\(payments[i % payments.count]),2024-\(String(format: "%02d", 1 + i % 12))-\(String(format: "%02d", 1 + i % 28)),\(hasShipDate ? "2024-\(String(format: "%02d", 1 + (i + 3) % 12))-\(String(format: "%02d", 1 + (i + 3) % 28))" : ""),\(statuses[i % statuses.count]),\(hasNotes ? "\"Rush order, handle with care\"" : "")\n"
+        let orderId = "ORD-\(String(format: "%08d", i))"
+        let customerId = "\(1000 + i % 500)"
+        let customerName = "\"Customer \(i)\""
+        let email = "customer\(i)@example.com"
+        let productId = "\(i % 1000)"
+        let productName = "\"Product \(i % 100)\""
+        let quantity = "\(1 + i % 10)"
+        let unitPrice = "\(Double(10 + i % 100))"
+        let discount = hasDiscount ? "0.1" : ""
+        let totalAmount = "\(Double(10 + i % 100) * Double(1 + i % 10))"
+        let payment = payments[i % payments.count]
+        let orderDate = "2024-\(String(format: "%02d", 1 + i % 12))-\(String(format: "%02d", 1 + i % 28))"
+        let shipDate = hasShipDate
+            ? "2024-\(String(format: "%02d", 1 + (i + 3) % 12))-\(String(format: "%02d", 1 + (i + 3) % 28))"
+            : ""
+        let status = statuses[i % statuses.count]
+        let notes = hasNotes ? "\"Rush order, handle with care\"" : ""
+        csv += "\(orderId),\(customerId),\(customerName),\(email),\(productId),\(productName),"
+        csv += "\(quantity),\(unitPrice),\(discount),0.08,5.99,\(totalAmount),USD,\(payment),"
+        csv += "\(orderDate),\(shipDate),\(status),\(notes)\n"
     }
     return csv
 }
@@ -215,7 +234,24 @@ nonisolated func generateTransactionCSV(rows: Int) -> String {
         let hasExchange = i % 4 == 0
         let hasRef = i % 3 == 0
         let hasProcessor = i % 2 == 0
-        csv += "TXN\(String(format: "%012d", i)),ACC\(String(format: "%08d", i % 10000)),ACC\(String(format: "%08d", (i + 5000) % 10000)),\(Double(100 + i % 10000)),\(currencies[i % currencies.count]),\(hasExchange ? "1.12" : ""),\(Double(i % 50) * 0.01),2024-\(String(format: "%02d", 1 + i % 12))-\(String(format: "%02d", 1 + i % 28))T\(String(format: "%02d", i % 24)):\(String(format: "%02d", i % 60)):00Z,\(categories[i % categories.count]),\"Transaction \(i) description\",\(hasRef ? "REF\(i)" : ""),completed,\(hasProcessor ? "PROC\(i % 100)" : "")\n"
+        let txnId = "TXN\(String(format: "%012d", i))"
+        let accountFrom = "ACC\(String(format: "%08d", i % 10000))"
+        let accountTo = "ACC\(String(format: "%08d", (i + 5000) % 10000))"
+        let amount = "\(Double(100 + i % 10000))"
+        let currency = currencies[i % currencies.count]
+        let exchangeRate = hasExchange ? "1.12" : ""
+        let fee = "\(Double(i % 50) * 0.01)"
+        let month = String(format: "%02d", 1 + i % 12)
+        let day = String(format: "%02d", 1 + i % 28)
+        let hour = String(format: "%02d", i % 24)
+        let minute = String(format: "%02d", i % 60)
+        let timestamp = "2024-\(month)-\(day)T\(hour):\(minute):00Z"
+        let category = categories[i % categories.count]
+        let description = "\"Transaction \(i) description\""
+        let reference = hasRef ? "REF\(i)" : ""
+        let processor = hasProcessor ? "PROC\(i % 100)" : ""
+        csv += "\(txnId),\(accountFrom),\(accountTo),\(amount),\(currency),\(exchangeRate),\(fee),"
+        csv += "\(timestamp),\(category),\(description),\(reference),completed,\(processor)\n"
     }
     return csv
 }
@@ -230,7 +266,26 @@ nonisolated func generateLogCSV(rows: Int) -> String {
         let hasUserId = i % 3 == 0
         let hasDuration = i % 2 == 0
         let hasMetadata = i % 5 == 0
-        csv += "2024-\(String(format: "%02d", 1 + i % 12))-\(String(format: "%02d", 1 + i % 28))T\(String(format: "%02d", i % 24)):\(String(format: "%02d", i % 60)):\(String(format: "%02d", i % 60)).\(String(format: "%03d", i % 1000))Z,\(levels[i % levels.count]),\(services[i % services.count]),host-\(i % 10).cluster.local,\(hasRequestId ? "req-\(UUID().uuidString.prefix(8))" : ""),\(hasUserId ? "user-\(i % 1000)" : ""),\(actions[i % actions.count]),/api/v1/resource/\(i % 100),\(hasDuration ? "\(50 + i % 500)" : ""),\(200 + (i % 5) * 100),\"Request processed successfully for item \(i)\",\(hasMetadata ? "\"{\"\"key\"\":\"\"value\"\"}\"" : "")\n"
+        let month = String(format: "%02d", 1 + i % 12)
+        let day = String(format: "%02d", 1 + i % 28)
+        let hour = String(format: "%02d", i % 24)
+        let minute = String(format: "%02d", i % 60)
+        let second = String(format: "%02d", i % 60)
+        let millis = String(format: "%03d", i % 1000)
+        let timestamp = "2024-\(month)-\(day)T\(hour):\(minute):\(second).\(millis)Z"
+        let level = levels[i % levels.count]
+        let service = services[i % services.count]
+        let host = "host-\(i % 10).cluster.local"
+        let requestId = hasRequestId ? "req-\(UUID().uuidString.prefix(8))" : ""
+        let userId = hasUserId ? "user-\(i % 1000)" : ""
+        let action = actions[i % actions.count]
+        let resource = "/api/v1/resource/\(i % 100)"
+        let duration = hasDuration ? "\(50 + i % 500)" : ""
+        let statusCode = "\(200 + (i % 5) * 100)"
+        let message = "\"Request processed successfully for item \(i)\""
+        let metadata = hasMetadata ? "\"{\"\"key\"\":\"\"value\"\"}\"" : ""
+        csv += "\(timestamp),\(level),\(service),\(host),\(requestId),\(userId),"
+        csv += "\(action),\(resource),\(duration),\(statusCode),\(message),\(metadata)\n"
     }
     return csv
 }
@@ -341,6 +396,7 @@ let simpleRecords100K = (0 ..< 100_000).map { SimpleRecord(
     score: Double($0) * 0.1,
 )
 }
+
 let simpleRecords1M = (0 ..< 1_000_000).map { SimpleRecord(
     name: "Person\($0)",
     age: 20 + $0 % 50,