{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# definitions"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {},
   "outputs": [],
   "source": [
    "type Integer int\n",
    "\n",
    "func (a Integer) Less(b Integer) bool {\n",
    "    return a < b\n",
    "}\n",
    "\n",
    "func (a *Integer) Add(b Integer) {\n",
    "    *a += b\n",
    "}"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# right"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [],
   "source": [
    "type LessAdder interface {\n",
    "    Add(b Integer)\n",
    "    Less(b Integer) bool\n",
    "//     Add(b Integer)\n",
    "}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [],
   "source": [
    "var a Integer = 1\n",
    "var b LessAdder = &a"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# wrong"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {},
   "outputs": [],
   "source": [
    "type LessAdder interface {\n",
    "//     Add(b Integer)\n",
    "    Less(b Integer) bool\n",
    "    Add(b Integer)\n",
    "}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "ename": "ERROR",
     "evalue": "reflect.Set: value of type func(int) is not assignable to type func(int) bool",
     "output_type": "error",
     "traceback": [
      "reflect.Set: value of type func(int) is not assignable to type func(int) bool"
     ]
    }
   ],
   "source": [
    "var a Integer = 1\n",
    "var b LessAdder = &a"
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Go",
   "language": "go",
   "name": "gophernotes"
  },
  "language_info": {
   "codemirror_mode": "",
   "file_extension": ".go",
   "mimetype": "",
   "name": "go",
   "nbconvert_exporter": "",
   "pygments_lexer": "",
   "version": "go1.10.2"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}