qhwa

      6c       f0       9f       8d       ad       70 =>
01101100 11110000 10011111 10001101 10101101 01110000

qhwa

      f0       9f       8d       ad =>
11110000 10011111 10001101 10101101 =>
-----xxx --xxxxxx --xxxxxx --xxxxxx =>
     000   011111   001101   101101 =>
     ┕━━━━━━━━━ 0x1f36d ━━━━━━━━━━┙

qhwa

defmodule MyBinParser1 do
  def valid?(<<length::2, data::binary>>),
    do: byte_size(data) >= length

  def valid?(_), do: false
end

defmodule MyBinParser2 do
  def valid?(<<length::2, _data::binary-size(length), _rest::binary>>),
    do: true

qhwa

iex> a_very_large_binary = :binary.copy("x", 1000)
...> <<_first_three_bytes::binary-3, rest::binary>> = a_very_large_binary
...> byte_size(rest)
997

...> :binary.referenced_byte_size(rest)
1000

qhwa

defmodule IEEE_754 do
  def friction_to_mantissa(""), do: 0
  def friction_to_mantissa(<<n::1, rest::bits>>),
    do: n + friction_to_mantissa(rest) * 0.5
end
iex> mantissa = IEEE_754.friction_to_mantissa(<<1::1, friction::bits>>)
...> :math.pow(-1, sign) * mantissa * :math.pow(2, exponent - 1023)
3.14

qhwa

defmodule RenderingDemo do
  @behaviour Ratatouille.App

  import Ratatouille.View

  def init(_context) do
    "Hello world! 你好世界! <<🦸🏻‍♀️🧖‍♀️>>"
  end

  def update(model, _message), do: model

qhwa

alias ExTermbox.Bindings, as: Termbox
alias ExTermbox.{Cell, EventManager, Event, Position}

:ok = Termbox.init()

{:ok, _pid} = EventManager.start_link()
:ok = EventManager.subscribe(self())

for {ch, x} <- Enum.with_index('Hello, World! 你好世界!') do
  :ok = Termbox.put_cell(%Cell{position: %Position{x: x, y: 0}, ch: ch})

qhwa

defmodule MnesiaExample do

  def demo do
    # Step 1: initialize
    setup

    # Step 2: write some datas into database
    seed

    # Step 3: read from database

qhwa

package main

import (
	"fmt"
	"io"
	"net"
)

func main() {
	ln, err := net.Listen("tcp", ":8080")

qhwa

# find users nearby a certain location and print them
# by qhwa
require 'json'
require 'ostruct'
require 'logger'

class User < OpenStruct

  OFFICE_GPS = [ 53.3381985, -6.2592576 ]