{
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  {
   "cell_type": "markdown",
   "id": "oo-0",
   "metadata": {},
   "source": "# Classes and object-oriented programming\n\nnumbl supports MATLAB's `classdef` object model: value and handle classes,\nconstructors, methods, inheritance, abstract methods, operator overloading,\nand static methods. Classes are defined in `.m` files next to the notebook\n(you can open and edit them in the file browser)."
  },
  {
   "cell_type": "markdown",
   "id": "oo-1",
   "metadata": {},
   "source": "## A value class with operator overloading\n\n[Vec2.m](./Vec2.m) overloads `+`, `-`, and `*` and defines `norm`."
  },
  {
   "cell_type": "code",
   "id": "oo-2",
   "metadata": {},
   "execution_count": null,
   "outputs": [],
   "source": "a = Vec2(3, 4);\nb = Vec2(1, 2);\nfprintf('a + b = %s\\n', char(a + b));\nfprintf('a - b = %s\\n', char(a - b));\nfprintf('3 * a = %s\\n', char(3 * a));\nfprintf('norm(a) = %g\\n', norm(a));"
  },
  {
   "cell_type": "markdown",
   "id": "oo-3",
   "metadata": {},
   "source": "## A handle class has reference semantics\n\n[Account.m](./Account.m) is a `handle` class, so assigning it does not copy:\nboth names refer to the same object."
  },
  {
   "cell_type": "code",
   "id": "oo-4",
   "metadata": {},
   "execution_count": null,
   "outputs": [],
   "source": "acct = Account(100);\ndeposit(acct, 50);\nalias = acct;\ndeposit(alias, 25);\nacct.Balance     % 175: updates are seen through both names"
  },
  {
   "cell_type": "markdown",
   "id": "oo-5",
   "metadata": {},
   "source": "## Inheritance, abstract methods, and polymorphism\n\n[Shape.m](./Shape.m) declares an abstract `area()` and a concrete\n`describe()`. [Circle.m](./Circle.m) and [Square.m](./Square.m) implement\n`area()`."
  },
  {
   "cell_type": "code",
   "id": "oo-6",
   "metadata": {},
   "execution_count": null,
   "outputs": [],
   "source": "shapes = {Circle(2), Square(3)};\nareas = cellfun(@(s) s.area(), shapes)\ncellfun(@(s) isa(s, 'Shape'), shapes)"
  },
  {
   "cell_type": "code",
   "id": "oo-7",
   "metadata": {},
   "execution_count": null,
   "outputs": [],
   "source": "for i = 1:numel(shapes)\n    shapes{i}.describe();\nend"
  },
  {
   "cell_type": "markdown",
   "id": "oo-8",
   "metadata": {},
   "source": "## Static methods and methods across files\n\n[MathX.m](./MathX.m) has a static method (called on the class, not an\ninstance). [@Poly/](./@Poly/Poly.m) is a class whose methods live in\nseparate files in its `@Poly` folder."
  },
  {
   "cell_type": "code",
   "id": "oo-9",
   "metadata": {},
   "execution_count": null,
   "outputs": [],
   "source": "MathX.hypot3(3, 4, 12)\np = Poly([1 -3 2]);     % x^2 - 3x + 2\np.evalAt(5)             % method from @Poly/evalAt.m\nroots(p.coeffs)'"
  },
  {
   "cell_type": "markdown",
   "id": "oo-10",
   "metadata": {},
   "source": "## Private helper methods\n\n[Temperature.m](./Temperature.m) keeps its conversion in a\n`methods (Access = private)` block, used internally by `fahrenheit`."
  },
  {
   "cell_type": "code",
   "id": "oo-11",
   "metadata": {},
   "execution_count": null,
   "outputs": [],
   "source": "t = Temperature(100);\nt.fahrenheit()"
  }
 ],
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