{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Match"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "1."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Fill the blanks\n",
    "enum Direction {\n",
    "    East,\n",
    "    West,\n",
    "    North,\n",
    "    South,\n",
    "}\n",
    "\n",
    "fn main() {\n",
    "    let direction = Direction::South;\n",
    "    match direction {\n",
    "        Direction::East => println!(\"East\"),\n",
    "        __  => { // Matching South or North here\n",
    "            println!(\"South or North\");\n",
    "        },\n",
    "        _ => println!(__),\n",
    "    };\n",
    "}\n",
    "\n",
    "main();"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "2. Match is an expression, so we can use it in assignments"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fn main() {\n",
    "    let boolean = true;\n",
    "\n",
    "    // Fill the blank with a match expression:\n",
    "    //\n",
    "    // boolean = true -> binary = 1\n",
    "    // boolean = false ->  binary = 0\n",
    "    let binary = __;\n",
    "\n",
    "    assert_eq!(binary, 1);\n",
    "\n",
    "    println!(\"Success!\");\n",
    "}\n",
    "\n",
    " main();"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "3. Using match to get the data an enum variant holds."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Fill in the blanks\n",
    "enum Message {\n",
    "    Quit,\n",
    "    Move { x: i32, y: i32 },\n",
    "    Write(String),\n",
    "    ChangeColor(i32, i32, i32),\n",
    "}\n",
    "\n",
    "fn main() {\n",
    "    let msgs = [\n",
    "        Message::Quit,\n",
    "        Message::Move{x:1, y:3},\n",
    "        Message::ChangeColor(255,255,0)\n",
    "    ];\n",
    "\n",
    "    for msg in msgs {\n",
    "        show_message(msg)\n",
    "    }\n",
    "\n",
    "    println!(\"Success!\");\n",
    "} \n",
    "\n",
    "fn show_message(msg: Message) {\n",
    "    match msg {\n",
    "        __ => { // match  Message::Move\n",
    "            assert_eq!(a, 1);\n",
    "            assert_eq!(b, 3);\n",
    "        },\n",
    "        Message::ChangeColor(_, g, b) => {\n",
    "            assert_eq!(g, __);\n",
    "            assert_eq!(b, __);\n",
    "        }\n",
    "        __ => println!(\"no data in these variants\")\n",
    "    }\n",
    "}\n",
    "\n",
    "main();"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# If let"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "4."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "fn main() {\n",
    "    let o = Some(7);\n",
    "\n",
    "    // Remove the whole `match` block, using `if let` instead \n",
    "    match o {\n",
    "        Some(i) => {\n",
    "            println!(\"This is a really long string and `{:?}`\", i);\n",
    "\n",
    "            println!(\"Success!\");\n",
    "        }\n",
    "        _ => {}\n",
    "    };\n",
    "}\n",
    "\n",
    "main();"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "5."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "// Fill in the blank\n",
    "enum Foo {\n",
    "    Bar(u8)\n",
    "}\n",
    "\n",
    "fn main() {\n",
    "    let a = Foo::Bar(1);\n",
    "\n",
    "    __ {\n",
    "        println!(\"foobar holds the value: {}\", i);\n",
    "\n",
    "        println!(\"Success!\");\n",
    "    }\n",
    "}\n",
    "\n",
    "main();"
   ]
  }
 ],
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  "kernelspec": {
   "display_name": "Rust",
   "language": "rust",
   "name": "rust"
  },
  "language_info": {
   "codemirror_mode": "rust",
   "file_extension": ".rs",
   "mimetype": "text/rust",
   "name": "rust",
   "pygment_lexer": "rust",
   "version": ""
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 "nbformat": 4,
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