Use string representation for CIDR and IPAddress types (#458)

This change adds extension to the CIDR and IPAddress types to implement
custom encode/decode functions for `Codable` conformance to use their
string representation as the output from encode and input to decode.
This would make the output from encoding this type (e.g. JSON) more
human-readable rather than using the internal integer representation.

Sources/ContainerizationExtras/CIDRv4.swift

@@ -16,7 +16,7 @@
 
 /// Describes an IPv4 CIDR address block.
 @frozen
-public struct CIDRv4: CustomStringConvertible, Equatable, Sendable, Hashable, Codable {
+public struct CIDRv4: CustomStringConvertible, Equatable, Sendable, Hashable {
     /// The IP component of this CIDR address.
     public let address: IPv4Address
 
@@ -99,3 +99,16 @@ public struct CIDRv4: CustomStringConvertible, Equatable, Sendable, Hashable, Co
         "\(address)/\(prefix)"
     }
 }
+
+extension CIDRv4: Codable {
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        let string = try container.decode(String.self)
+        try self.init(string)
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(description)
+    }
+}

Sources/ContainerizationExtras/CIDRv6.swift

@@ -16,7 +16,7 @@
 
 /// Describes an IPv4 or IPv6 CIDR address block.
 @frozen
-public struct CIDRv6: CustomStringConvertible, Equatable, Sendable, Hashable, Codable {
+public struct CIDRv6: CustomStringConvertible, Equatable, Sendable, Hashable {
 
     /// The IP component of this CIDR address.
     public let address: IPv6Address
@@ -100,3 +100,16 @@ public struct CIDRv6: CustomStringConvertible, Equatable, Sendable, Hashable, Co
         "\(address)/\(prefix)"
     }
 }
+
+extension CIDRv6: Codable {
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        let string = try container.decode(String.self)
+        try self.init(string)
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(description)
+    }
+}

Sources/ContainerizationExtras/IPv4Address.swift

@@ -15,7 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 @frozen
-public struct IPv4Address: Sendable, Hashable, CustomStringConvertible, Equatable, Comparable, Codable {
+public struct IPv4Address: Sendable, Hashable, CustomStringConvertible, Equatable, Comparable {
     public let value: UInt32
 
     @inlinable
@@ -215,3 +215,16 @@ public struct IPv4Address: Sendable, Hashable, CustomStringConvertible, Equatabl
         lhs.value < rhs.value
     }
 }
+
+extension IPv4Address: Codable {
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        let string = try container.decode(String.self)
+        try self.init(string)
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(description)
+    }
+}

Sources/ContainerizationExtras/IPv6Address.swift

@@ -15,7 +15,7 @@
 //===----------------------------------------------------------------------===//
 
 /// Represents an IPv6 network address conforming to RFC 5952 and RFC 4291.
-public struct IPv6Address: Sendable, Hashable, CustomStringConvertible, Equatable, Comparable, Codable {
+public struct IPv6Address: Sendable, Hashable, CustomStringConvertible, Equatable, Comparable {
     public let value: UInt128
 
     public let zone: String?
@@ -252,3 +252,16 @@ public struct IPv6Address: Sendable, Hashable, CustomStringConvertible, Equatabl
         return (lhs.zone ?? "") < (rhs.zone ?? "")
     }
 }
+
+extension IPv6Address: Codable {
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        let string = try container.decode(String.self)
+        try self.init(string)
+    }
+
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(description)
+    }
+}