DSL Style for Byte Array Creation

Sources/BitWiser/DSL/ByteArrayBuilder.swift

@@ -0,0 +1,44 @@
+//
+//  ByteArrayBuilder.swift
+//  
+//
+//  Created by Andrea Finollo on 30/01/22.
+//
+
+import Foundation
+
+
+/// `ByteArrayBuilder` is a `@resultBuilder` to create sequence of `Byte` in a DSL style
+@resultBuilder
+public enum ByteArrayBuilder {
+
+    public static func buildBlock(_ components: [Byte]...) -> [Byte] {
+        components.flatMap { $0 }
+    }
+
+    public static func buildExpression(_ expression: [Byte]) -> [Byte] {
+        expression
+    }
+
+    public static func buildExpression(_ expression: Byte) -> [Byte] {
+        [expression]
+    }
+
+    public static func buildOptional(_ component: [Byte]?) -> [Byte] {
+        component ?? []
+    }
+
+    public static func buildEither(first component: [Byte]) -> [Byte] {
+        component
+    }
+
+    public static func buildEither(second component: [Byte]) -> [Byte] {
+        component
+    }
+
+    public static func buildArray(_ components: [[Byte]]) -> [Byte] {
+        return components.flatMap { $0 }
+    }
+
+
+}

Sources/BitWiser/DSL/DataConvertibleBuilder.swift

@@ -0,0 +1,55 @@
+//
+//  DataConvertibleBuilder.swift
+//  
+//
+//  Created by Andrea Finollo on 04/02/22.
+//
+
+import Foundation
+
+/// `DataConvertibleBuilder` is a `@resultBuilder` to create  `Data` in a DSL style
+@resultBuilder
+public enum DataConvertibleBuilder {
+
+    public static func buildBlock(_ components: DataConvertible...) -> Data {
+        return components.reduce(Data()) { partialResult, value in
+            var mutBuffer = partialResult
+            mutBuffer.append(value.data)
+            return mutBuffer
+        }
+    }
+
+    public static func buildExpression(_ expression: [DataConvertible]) -> Data {
+        return expression.reduce(Data()) { partialResult, value in
+            var mutBuffer = partialResult
+            mutBuffer.append(value.data)
+            return mutBuffer
+        }
+    }
+
+    public static func buildExpression(_ expression: DataConvertible) -> Data {
+        expression.data
+    }
+
+    public static func buildOptional(_ component: DataConvertible?) -> Data {
+        return component?.data ?? Data()
+    }
+
+    public static func buildEither(first component: DataConvertible) -> Data {
+        return component.data
+    }
+
+    public static func buildEither(second component: DataConvertible) -> Data {
+        return component.data
+    }
+
+    public static func buildArray(_ components: [DataConvertible]) -> Data {
+        return components
+            .reduce(Data()) { partialResult, value in
+                var mutBuffer = partialResult
+                mutBuffer.append(value.data)
+                return mutBuffer
+            }
+    }
+
+}

Sources/BitWiser/DataRepresentable/DataRepresentable.swift

@@ -0,0 +1,18 @@
+//
+//  DataRepresentable.swift
+//  
+//
+//  Created by Andrea Finollo on 04/02/22.
+//
+
+import Foundation
+
+public protocol ExpressibleByData {
+    init?(data: Data)
+}
+
+public protocol DataConvertible {
+    var data: Data { get }
+}
+
+public typealias DataRepresentable = ExpressibleByData & DataConvertible

Sources/BitWiser/Extension/Extension+Data.swift

@@ -18,6 +18,17 @@ extension Data: ByteRepresentable {
     }
 }
 
+extension Data : DataConvertible {
+
+    public init?(data: Data) {
+        self.init(data)
+    }
+
+    public var data: Data {
+        return self
+    }
+}
+
 public extension Data {
 
     /// Option about how to encode the hex string representation
@@ -44,3 +55,23 @@ public extension Data {
         }.joined(separator: padding)
     }
 }
+
+public extension Data {
+
+    /// Initialize a `Data` with a `@DataConvertibleBuilder`.
+    ///
+    ///     Data {
+    ///         [Byte(0x00)]
+    ///         Byte(0x01)
+    ///         0x02
+    ///         "\u{03}"
+    ///         CustomObject()
+    ///     }
+    ///
+    /// - parameter representables: A DSL closure with `DataRepresentable`s. Object passed in the closure must conform to `DataRepresentable` protocol.
+    /// - Note: Objects passed in the closure can have different `Data` lenght.
+    /// - Important: Always start from the LSB.
+    init(@DataConvertibleBuilder _ representables: () -> Data) {
+        self.init(representables())
+    }
+}

Sources/BitWiser/Extension/Extension+Numeric.swift

@@ -7,6 +7,34 @@
 
 import Foundation
 
+extension DataConvertible where Self: ExpressibleByIntegerLiteral{
+    public init?(data: Data) {
+        var value: Self = 0
+        guard data.count == MemoryLayout.size(ofValue: value) else { return nil }
+        _ = withUnsafeMutableBytes(of: &value, { data.copyBytes(to: $0)} )
+        self = value
+    }
+
+    public var data: Data {
+        return withUnsafeBytes(of: self) { Data($0) }
+    }
+}
+
+extension Int8: DataConvertible { }
+extension Int16: DataConvertible { }
+extension Int32: DataConvertible { }
+extension Int64: DataConvertible { }
+extension Int: DataConvertible { }
+
+extension Float: DataConvertible { }
+extension Double: DataConvertible { }
+
+extension UInt8: DataConvertible { }
+extension UInt16: DataConvertible { }
+extension UInt32: DataConvertible { }
+extension UInt64: DataConvertible { }
+extension UInt: DataConvertible { }
+
 // MARK: - Signed Numeric
 
 extension Int16: ByteConvertible {
@@ -103,3 +131,20 @@ extension Array where Element == Byte {
         return or
     }
 }
+
+public extension Array where Element == Byte {
+    /// Initialize a `[Byte]`Array  with a `@ByteArrayBuilder`.
+    ///
+    ///     Array<Byte> {
+    ///         [Byte(0x00)]
+    ///         Byte(0x01)
+    ///         0x02
+    ///         [UInt8(0x03)]
+    ///     }
+    ///
+    /// - parameter builder: A DSL closure with `Byte`s.
+    /// - Important: Always start from the LSB
+    init(@ByteArrayBuilder _ builder: () -> [Byte]) {
+        self.init(builder())
+    }
+}

Sources/BitWiser/Extension/Extension+String.swift

@@ -7,6 +7,18 @@
 
 import Foundation
 
+extension String: DataConvertible {
+
+    public init?(data: Data) {
+        self.init(data: data, encoding: .utf8)
+    }
+
+    public var data: Data {
+        // Note: a conversion to UTF-8 cannot fail.
+        return Data(self.utf8)
+    }
+}
+
 public extension String {
     /// Given a hex string it returns a Data
     /// - Returns: a `Data` value

Tests/BitWiserTests/ByteTests.swift

@@ -16,7 +16,7 @@ class ByteTests: XCTestCase {
         var hexDescription = value.hexDescription
         XCTAssertTrue(binDescription == "00000000")
         XCTAssertTrue(hexDescription == "00")
-
+        
         value = 0b11111111
         binDescription = value.binaryDescription
         hexDescription = value.hexDescription