{
  "cells" : [
    {
      "outputs" : [
        
      ],
      "metadata" : {
        
      },
      "source" : [
        "%install-location $cwd\/swift-install\n",
        "%install '.package(path: \"$cwd\/FastaiNotebook_08_data_block\")' FastaiNotebook_08_data_block"
      ],
      "cell_type" : "code",
      "execution_count" : null
    },
    {
      "cell_type" : "code",
      "metadata" : {
        
      },
      "source" : [
        "\/\/ export\n",
        "import Path"
      ],
      "execution_count" : null,
      "outputs" : [
        
      ]
    },
    {
      "outputs" : [
        
      ],
      "metadata" : {
        
      },
      "source" : [
        "import FastaiNotebook_08_data_block"
      ],
      "cell_type" : "code",
      "execution_count" : null
    },
    {
      "outputs" : [
        
      ],
      "metadata" : {
        
      },
      "source" : [
        "\/\/ export\n",
        "public protocol HetDictKey {\n",
        "    associatedtype ValueType\n",
        "    static var defaultValue: ValueType { get }\n",
        "}"
      ],
      "execution_count" : null,
      "cell_type" : "code"
    },
    {
      "cell_type" : "code",
      "metadata" : {
        
      },
      "source" : [
        "\/\/ export\n",
        "\n",
        "public struct HeterogeneousDictionary {\n",
        "    private var underlying: [ObjectIdentifier : Any] = [:]\n",
        "    \n",
        "    public init() {}\n",
        "    public init<T: HetDictKey>(_ key: T.Type, _ value: T.ValueType) {\n",
        "        self.underlying = [ObjectIdentifier(key): value]\n",
        "    }\n",
        "    public init<T1: HetDictKey, T2: HetDictKey>(_ key1: T1.Type, _ value1: T1.ValueType, _ key2: T2.Type, _ value2: T2.ValueType) {\n",
        "        self.underlying = [ObjectIdentifier(key1): value1, ObjectIdentifier(key2): value2]\n",
        "    }\n",
        "\n",
        "    public subscript<T: HetDictKey>(key: T.Type) -> T.ValueType {\n",
        "        get { return underlying[ObjectIdentifier(key), default: T.defaultValue] as! T.ValueType }\n",
        "        set { underlying[ObjectIdentifier(key)] = newValue as Any }\n",
        "    }\n",
        "    \n",
        "    public mutating func merge(_ other: HeterogeneousDictionary,\n",
        "        uniquingKeysWith combine: (Any, Any) throws -> Any) rethrows {\n",
        "        try self.underlying.merge(other.underlying, uniquingKeysWith: combine)\n",
        "    }\n",
        "}"
      ],
      "outputs" : [
        
      ],
      "execution_count" : null
    },
    {
      "outputs" : [
        
      ],
      "metadata" : {
        
      },
      "source" : [
        "\/\/ export\n",
        "\/\/ Common keys\n",
        "public struct LearningRate: HetDictKey {\n",
        "    public static var defaultValue: Float = 0.4\n",
        "}"
      ],
      "cell_type" : "code",
      "execution_count" : null
    },
    {
      "execution_count" : null,
      "metadata" : {
        
      },
      "source" : [
        "public struct StepCount: HetDictKey {\n",
        "    public static var defaultValue = 0\n",
        "}"
      ],
      "cell_type" : "code",
      "outputs" : [
        
      ]
    },
    {
      "execution_count" : null,
      "metadata" : {
        
      },
      "source" : [
        "\/\/ Sample usage\n",
        "var m = HeterogeneousDictionary()\n"
      ],
      "cell_type" : "code",
      "outputs" : [
        
      ]
    },
    {
      "execution_count" : null,
      "metadata" : {
        
      },
      "source" : [
        "print(m[LearningRate.self])\n",
        "m[LearningRate.self] = 3.4\n",
        "print(m[LearningRate.self])\n",
        "\n",
        "print(m[StepCount.self])\n",
        "m[StepCount.self] = 3\n",
        "print(m[StepCount.self])\n"
      ],
      "outputs" : [
        
      ],
      "cell_type" : "code"
    },
    {
      "outputs" : [
        
      ],
      "metadata" : {
        
      },
      "source" : [
        "print(type(of: m[StepCount.self]))\n",
        "print(type(of: m[LearningRate.self]))\n"
      ],
      "execution_count" : null,
      "cell_type" : "code"
    },
    {
      "cell_type" : "markdown",
      "metadata" : {
        
      },
      "source" : [
        "## Export"
      ]
    },
    {
      "cell_type" : "code",
      "metadata" : {
        
      },
      "source" : [
        "import NotebookExport\n",
        "let exporter = NotebookExport(Path.cwd\/\"08a_heterogeneous_dictionary.ipynb\")\n",
        "print(exporter.export(usingPrefix: \"FastaiNotebook_\"))"
      ],
      "outputs" : [
        
      ],
      "execution_count" : null
    },
    {
      "execution_count" : null,
      "metadata" : {
        
      },
      "source" : [
        
      ],
      "cell_type" : "code",
      "outputs" : [
        
      ]
    }
  ],
  "metadata" : {
    "kernelspec" : {
      "display_name" : "Swift",
      "name" : "swift",
      "language" : "swift"
    }
  },
  "nbformat_minor" : 2,
  "nbformat" : 4
}