{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# Nim Magic\n",
    "\n",
    "This notebook explores making a cell magic for nim."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "First, we load libs that we will need for defining an IPython magic:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 12,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "from IPython.core.magic import register_line_cell_magic"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "Now, we construct a file that contains nim code:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 13,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Overwriting default.nim\n"
     ]
    }
   ],
   "source": [
    "%%file default.nim\n",
    "\n",
    "# This is a comment\n",
    "echo(\"What's your name? \")\n",
    "var name: string = \"Kevin\"\n",
    "echo(\"Hi, \", name, \"!\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "Can we run the file and view the results?"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 14,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "What's your name? \n",
      "Hi, Kevin!\n",
      "/etc/nim.cfg(53, 2) Hint: added path: '/home/dblank/.babel/pkgs/' [Path]\n",
      "/etc/nim.cfg(54, 2) Hint: added path: '/home/dblank/.nimble/pkgs/' [Path]\n",
      "Hint: used config file '/etc/nim.cfg' [Conf]\n",
      "Hint: system [Processing]\n",
      "Hint: default [Processing]\n",
      "[Linking]\n",
      "Hint: operation successful (9000 lines compiled; 0.144 sec total; 14.148MB; Debug Build) [SuccessX]\n",
      "/home/dblank/default \n",
      "\n"
     ]
    }
   ],
   "source": [
    "import subprocess\n",
    "import sys\n",
    "p = subprocess.Popen([\"nim\", \"compile\", \"--run\", \"default.nim\"], stdout=subprocess.PIPE)\n",
    "out, err = p.communicate()\n",
    "if err:\n",
    "    print(err.decode(\"utf-8\"), file=sys.stderr)\n",
    "if out:\n",
    "    print(out.decode(\"utf-8\"))"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": [
    "Now, we put that together into a cell magic:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "@register_line_cell_magic\n",
    "def nim(line, cell):\n",
    "    fp = open(\"default.nim\", \"w\")\n",
    "    fp.write(cell)\n",
    "    fp.close()\n",
    "    p = subprocess.Popen([\"nim\", \"compile\", \"--run\", \"default.nim\"], stdout=subprocess.PIPE)\n",
    "    out, err = p.communicate()\n",
    "    if err:\n",
    "        print(err.decode(\"utf-8\"), file=sys.stderr)\n",
    "    if out:\n",
    "        print(out.decode(\"utf-8\"))    "
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "And now test it out:"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 21,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "woof\n",
      "70\n",
      "meow\n",
      "10\n",
      "/etc/nim.cfg(53, 2) Hint: added path: '/home/dblank/.babel/pkgs/' [Path]\n",
      "/etc/nim.cfg(54, 2) Hint: added path: '/home/dblank/.nimble/pkgs/' [Path]\n",
      "Hint: used config file '/etc/nim.cfg' [Conf]\n",
      "Hint: system [Processing]\n",
      "Hint: default [Processing]\n",
      "CC: default\n",
      "CC: system\n",
      "[Linking]\n",
      "Hint: operation successful (9017 lines compiled; 0.791 sec total; 14.148MB; Debug Build) [SuccessX]\n",
      "/home/dblank/default \n",
      "\n"
     ]
    }
   ],
   "source": [
    "%%nim \n",
    "\n",
    "type Animal = ref object of RootObj\n",
    "  name: string\n",
    "  age: int\n",
    "method vocalize(this: Animal): string = \"...\"\n",
    "method ageHumanYrs(this: Animal): int = this.age\n",
    "\n",
    "type Dog = ref object of Animal\n",
    "method vocalize(this: Dog): string = \"woof\"\n",
    "method ageHumanYrs(this: Dog): int = this.age * 7\n",
    "\n",
    "type Cat = ref object of Animal\n",
    "method vocalize(this: Cat): string = \"meow\"\n",
    "\n",
    "\n",
    "var animals: seq[Animal] = @[]\n",
    "animals.add(Dog(name: \"Sparky\", age: 10))\n",
    "animals.add(Cat(name: \"Mitten\", age: 10))\n",
    "\n",
    "for a in animals:\n",
    "  echo a.vocalize()\n",
    "  echo a.ageHumanYrs()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {
    "collapsed": true
   },
   "outputs": [],
   "source": []
  }
 ],
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  "kernelspec": {
   "display_name": "Python 3",
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  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
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   "file_extension": ".py",
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