Code Snippets for Drupaljam:XL 2019 and DrupalCon Amsterdam 2019

- Multilingualism Makes Better Programmers.md

Multilingualism makes better programmers

The below Gist contains the code samples that I've used in my talk "Multilingualism makes better programmers".

closures-1.js

function init() {
  var name = 'Mozilla'; // name is a local variable created by init
  function displayName() { // displayName() is the inner function, a closure
    console.log(name); // use variable declared in the parent function
  }
  displayName();
}

// Outputs: Mozilla
init();

// Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures

closures-2.js

function makeFunc() {
  var name = 'Mozilla';
  function displayName() {
    console.log(name);
  }
  return displayName;
}

var myFunc = makeFunc();

// Outputs: Mozilla
myFunc();

// Source: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Closures

closures-3.js

function makeAdder(x) {
  return y => x + y;
}

var add6 = makeAdder(6);
var add9 = makeAdder(9);

console.log(add6(9));  // 14
console.log(add9(9));  // 18

closures-arrow.js

function addFunction (x) {
  return x + 5;
}

const addArrowFn = x => x + 5;

console.log(addFunction(2)); // 7
console.log(addArrowFn(2)); // 7

complex-match.rs

enum OptionalInt {
    Value(i32),
    Missing,
}

let x = OptionalInt::Value(5);

match x {
    OptionalInt::Value(i) if i > 5 => println!("Got an int bigger than five!"),
    OptionalInt::Value(..) => println!("Got an int!"),
    OptionalInt::Missing => println!("No such luck."),
}

// Source: https://doc.rust-lang.org/1.5.0/book/patterns.html

ContentEntityBase-get.php

<?php
/**
 * Implements the magic method for getting object properties.
 *
 * @todo: A lot of code still uses non-fields (e.g. $entity->content in view
 *   builders) by reference. Clean that up.
 */
public function &__get($name) {
  // If this is an entity field, handle it accordingly. We first check whether
  // a field object has been already created. If not, we create one.
  if (isset($this->fields[$name][$this->activeLangcode])) {
    return $this->fields[$name][$this->activeLangcode];
  }
  // Inline getFieldDefinition() to speed things up.
  if (!isset($this->fieldDefinitions)) {
    $this->getFieldDefinitions();
  }
  if (isset($this->fieldDefinitions[$name])) {
    $return = $this->getTranslatedField($name, $this->activeLangcode);
    return $return;
  }
  // Else directly read/write plain values. That way, non-field entity
  // properties can always be accessed directly.
  if (!isset($this->values[$name])) {
    $this->values[$name] = NULL;
  }
  return $this->values[$name];
}

contingency-methods.rb

# bad
begin
  something_that_might_fail
rescue IOError
  # handle IOError
end

begin
  something_else_that_might_fail
rescue IOError
  # handle IOError
end

# good
def with_io_error_handling
   yield
rescue IOError
  # handle IOError
end

with_io_error_handling { something_that_might_fail }

with_io_error_handling { something_else_that_might_fail }

decorator-example.js

import { @set } from "./set.mjs";
import { @tracked } from "./tracked.mjs";
import { @bound } from "./bound.mjs";
import { @defineElement } from "./defineElement.mjs";

@defineElement('counter-widget')
class CounterWidget extends HTMLElement {
  @tracked x = 0;

  @set onclick = this.clicked;

  @bound clicked() { this.x++; }

  connectedCallback() { this.render(); }

  render() { this.textContent = this.x.toString(); }
}

// Source: https://github.com/tc39/proposal-decorators

echo.asm

DATA SEGMENT
  MESSAGE DB "ENTER CHARACTER :$"
  X DB ?
ENDS

CODE SEGMENT
  ASSUME DS:DATA CS:CODE
START:
  MOV AX,DATA
  MOV DS,AX
  LEA DX,MESSAGE
  MOV AH,9
  INT 21H
  MOV AH,1
  INT 21H
  MOV X,AL
  MOV AH,4CH
  INT 21H
ENDS
END START

; Source: http://cssimplified.com/computer-organisation-and-assembly-language-programming/an-assembly-program-to-read-a-character-from-console-and-echo-it

echo.c

#include <stdio.h>

int main() {
  printf("ENTER CHARACTER: ");
  char input = getchar();
  printf("%s\n", &input);
  return 0;
}

echo.cpp

#include <iostream>

int main() {
    char x;
    std::cout << "ENTER CHARACTER: ";
    // Technically reads a line.
    std::cin >> x; 
    std::cout << x;
    return 0;
}

echo.js

const readline = require('readline');

const rl = readline.createInterface({
  input: process.stdin,
  output: process.stdout
});

// Reads an entire line instead of a single character.
rl.question('ENTER CHARACTER: ', char => {
  console.log(char);
  rl.close();
});

echo.php

<?php
echo "ENTER CHARACTER: ";
$x = stream_get_contents(STDIN, 1);
echo "$x\n";

echo.py

import sys

print("ENTER CHARACTER:", end=" ")
sys.stdout.flush()
c = sys.stdin.read(1)
print(c)

enum.rs

// Create an `enum` to classify a web event. Note how both
// names and type information together specify the variant:
// `PageLoad != PageUnload` and `KeyPress(char) != Paste(String)`.
// Each is different and independent.
enum WebEvent {
    // An `enum` may either be `unit-like`,
    PageLoad,
    PageUnload,
    // like tuple structs,
    KeyPress(char),
    Paste(String),
    // or like structures.
    Click { x: i64, y: i64 },
}

// Source https://doc.rust-lang.org/stable/rust-by-example/custom_types/enum.html

ExampleMinecraftMod.java

package com.example.examplemod;

import net.minecraft.init.Blocks;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.Mod.EventHandler;
import net.minecraftforge.fml.common.event.FMLInitializationEvent;

@Mod(modid = ExampleMod.MODID, version = ExampleMod.VERSION)
public class ExampleMod
{
    public static final String MODID = "examplemod";
    public static final String VERSION = "1.0";

    @EventHandler
    public void init(FMLInitializationEvent event)
    {
        // some example code
        System.out.println("DIRT BLOCK >> "+Blocks.dirt.getUnlocalizedName());
    }
}

// Source: Minecraft Modding with Forge (Arun Gupta & Aditya Gupta, April 2015, O'Reilly Media, Inc.)

function-factory-closure.php

<?php

// As of PHP 7.4.
function createCartExchanger(string $currency, float $rate) {
  return fn($item) => [
    'label' => $item['label'],
    'currency' => $currency,
    'price' => $item['price'] * $rate,
  ];
}

$cartToEuro = createCartExchanger('eur', 0.88);

$cartInEur = array_map($cartToEuro, $cart);

function-factory.php

<?php
function createCartExchanger(string $currency, float $rate) {
  return function (array $item) use ($currency, $rate) {
    return [
      'label' => $item['label'],
      'currency' => $currency,
      'price' => $item['price'] * $rate,
    ];
  };
}

$cartToEuro = createCartExchanger('eur', 0.88);

$cartInEur = array_map($cartToEuro, $cart);

functional-1.js

// Exchange rate on 27-06-2019.
const usdToEur = usd => usd * 0.88;

const cart = [
  { label: 'Socks', currency: 'usd', price: 3.99 } ,
  { label: 'Shirt', currency: 'usd', price: 9.99 } ,
  { label: 'Shoes', currency: 'usd', price: 49.99 },
];

for (let i=0; i<cart.length; i++) {
  cart[i].price = usdToEur(cart[i].price);
}

// Outputs:
// [ { label: 'Socks', currency: 'eur', price: 3.5112 },
//   { label: 'Shirt', currency: 'eur', price: 8.7912 },
//   { label: 'Shoes', currency: 'eur', price: 43.9912 } ]
console.dir(cart);

functional-2.js

// Exchange rate on 27-06-2019.
const usdToEur = usd => usd * 0.88;

const cart = [
  { label: 'Socks', currency: 'usd', price: 3.99 } ,
  { label: 'Shirt', currency: 'usd', price: 9.99 } ,
  { label: 'Shoes', currency: 'usd', price: 49.99 },
];

const cartInEur = cart.map(item => ({
  label: item.label,
  currency: 'eur',
  price: usdToEur(item.price),
}));

// Outputs:
// [ { label: 'Socks', currency: 'eur', price: 3.5112 },
//   { label: 'Shirt', currency: 'eur', price: 8.7912 },
//   { label: 'Shoes', currency: 'eur', price: 43.9912 } ]
console.dir(cartInEur);

functional-3.js

const cart = [
  { label: 'Socks', currency: 'usd', price: 3.99 } ,
  { label: 'Shirt', currency: 'usd', price: 9.99 } ,
  { label: 'Shoes', currency: 'usd', price: 49.99 },
];

function createCartExchanger(currency, rate) {
  return item => ({
    label: item.label,
    currency: currency,
    price: item.price * rate,
  });
}

// Exchange rate on 27-06-2019.
const cartToEuro = createCartExchanger('eur', 0.88);
const cartToYen = createCartExchanger('yen', 107.87);

const cartInEur = cart.map(cartToEuro);
const cartInYen = cart.map(cartToYen);

// Outputs:
// [ { label: 'Socks', currency: 'eur', price: 3.5112 },
//   { label: 'Shirt', currency: 'eur', price: 8.7912 },
//   { label: 'Shoes', currency: 'eur', price: 43.9912 } ]
console.dir(cartInEur);

// Outputs:
// [ { label: 'Socks', currency: 'yen', price: 430.40130000000005 },
//   { label: 'Shirt', currency: 'yen', price: 1077.6213 },
//   { label: 'Shoes', currency: 'yen', price: 5392.421300000001 } ]
console.dir(cartInYen);

functional-4.js

const cart = [
  { label: 'Socks', currency: 'usd', price: 3.99 } ,
  { label: 'Shirt', currency: 'usd', price: 9.99 } ,
  { label: 'Shoes', currency: 'usd', price: 49.99 },
];

const sum = (total, item) => total + item.price;

const cartTotal = cart.reduce(sum, 0);

console.log(cartTotal);

if-as-modifier.js

function p(x) { process.stdout.write(x); }
function ret_true() { p("true "); return true; }
function ret_false() { p("false "); return false; }
function nl() { process.stdout.write("\n"); }

ret_true()  && p("&& print"); nl();
ret_true()  || p("|| print"); nl();
ret_false() && p("&& print"); nl();
ret_false() || p("|| print"); nl();

if-as-modifier.php

<?php
function p($x) { echo $x; }
function ret_true() { echo "true "; return true; }
function ret_false() { echo "false "; return false; }
function nl() { echo "\n"; }

ret_true()  && p("&& print"); nl();
ret_true()  || p("|| print"); nl();
ret_false() && p("&& print"); nl();
ret_false() || p("|| print"); nl();

if-as-modifier.rb

# good (doesn't work in PHP/JS)
do_something if some_condition

# another good option
some_condition && do_something

ImageWidget-AnnotationExample.php

<?php

namespace Drupal\image\Plugin\Field\FieldWidget;

/**
 * Plugin implementation of the 'image_image' widget.
 *
 * @FieldWidget(
 *   id = "image_image",
 *   label = @Translation("Image"),
 *   field_types = {
 *     "image"
 *   }
 * )
 */
class ImageWidget extends FileWidget {
  // Body omitted
}

IncorrectLanguage.php

<?php

class Gibberish implements LanguageInterface {
  // Required methods omitted for brevity.

  public function getDirection() {
    return 'outside-in';
  }
}

IncorrectLanguage.rs

enum LanguageDirection {
    LTR,
    RTL,
}

trait LanguageInterface {
    fn get_direction() -> LanguageDirection;
}

struct Gibberish {}

impl LanguageInterface for Gibberish {
    fn get_direction() -> LanguageDirection {
        "outside-in"
    }
}

intermediate-match.rs

match x {
    e @ 1 ... 5 => println!("got a range element {}", e),
    i => println!("{} was not in our range", i),
}

// Source: https://doc.rust-lang.org/1.5.0/book/patterns.html

LanguageInterface.php

<?php

namespace Drupal\Core\Language;

/**
 * Defines a language.
 */
interface LanguageInterface {
  // [Snip]
  /**
   * Language written left to right. Possible value of $language->direction.
   */
  const DIRECTION_LTR = 'ltr';

  /**
   * Language written right to left. Possible value of $language->direction.
   */
  const DIRECTION_RTL = 'rtl';

  // [Snip]
  
  /**
   * Gets the text direction (left-to-right or right-to-left).
   *
   * @return string
   *   Either self::DIRECTION_LTR or self::DIRECTION_RTL.
   */
  public function getDirection();

  // [Snip]
}

nullable-problems.php

<?php

/**
 * Loads an entity.
 *
 * @param mixed $id
 *   The id of the entity to load.
 *
 * @return static
 *   The entity object or NULL if there is no entity with the given ID.
 */

// Given we have < 9000 nodes.
// Throws: Error: Call to a member function label() on null
Node::load(9002)->label();

operator-precedence.php

<?php
do_something() and something_else() or try_something_different()

read-file-correct.rs

use std::fs::File;
use std::io::prelude::*;

fn main() {
    let file = File::open("foo.txt");

    match file {
        Ok(mut f) => {
            let mut contents = String::new();
            f.read_to_string(&mut contents).expect("Reading failed");

            println!("The contents of the file: {}", contents);
        },
        Err(_) => println!("Could not open file!")
    }
}

read-file-no-match.rs

use std::fs::File;
use std::io::prelude::*;

fn main() {
    let file = File::open("foo.txt");
    let mut contents = String::new();

    file.read_to_string(&mut contents);
    println!("The contents of the file: {}", contents);
}

read-file-unhandled.rs

use std::fs::File;
use std::io::prelude::*;

fn main() {
    let file = File::open("foo.txt");

    match file {
        Ok(mut f) => {
            let mut contents = String::new();
            f.read_to_string(&mut contents).expect("Reading failed");
        }
    }
}

result.rs

enum Result<T, E> {
   Ok(T),
   Err(E),
}

// Source: https://doc.rust-lang.org/std/result/

schwartzian-transform-1.js

const unsorted = [2, 0, 5, 3, 1, 4];
let seen = [0, 0, 0, 0, 0, 0];

// Slice copies the array.
const sorted = unsorted.slice().sort(
  (a, b) => {
    seen[a]++;
    seen[b]++;
    return a - b;
  }
);

console.log("Number\tTimes seen");
seen.forEach((times, number) => {
  console.log(`${number}\t${times}`);
});

// Number	Times seen
// 0	3
// 1	3
// 2	5
// 3	4
// 4	3
// 5	4

schwartzian-transform-2.js

// slowTransform: wait 1s and return x * 2.
const slowTransform = (x) => {
  var waitTill = new Date(new Date().getTime() + 1 * 1000);
  while(waitTill > new Date()){}

  return x * 2;
}

const unsorted = [2, 0, 5, 3, 1, 4];

// Slice copies the array.
const sorted = unsorted.slice().sort(
  (a, b) => {
    // Access network, disk, calculate prime number or fibonacci.
    return slowTransform(a) - slowTransform(b);
  }
);

// [ 0, 1, 2, 3, 4, 5 ]
console.log(sorted);

// Takes about 22 seconds.

schwartzian-transform-3.js

const slowTransform = (x) => {
  var waitTill = new Date(new Date().getTime() + 1 * 1000);
  while(waitTill > new Date()){}

  return x * 2;
}

const unsorted = [2, 0, 5, 3, 1, 4];

// Slice copies the array.
const sorted = unsorted.slice()
  .map(slowTransform)
  .sort(
    (a, b) => {
      // Access network, disk, calculate prime number or fibonacci.
      return a - b;
    }
  );

// [ 0, 2, 4, 6, 8, 10 ]
console.log(sorted);

// Takes about 6 seconds.

schwartzian-transform-4.js

const slowTransform = (x) => {
  var waitTill = new Date(new Date().getTime() + 1 * 1000);
  while(waitTill > new Date()){}

  return x * 2;
}

const unsorted = [2, 0, 5, 3, 1, 4];

// Slice copies the array.
const sorted = unsorted.slice()
  .map(x => [x, slowTransform(x)])
  .sort(
    (a, b) => {
      // Access network, disk, calculate prime number or fibonacci.
      return a[1] - b[1];
    }
  )
  .map(x => x[0]);

// [ 0, 1, 2, 3, 4, 5 ]
console.log(sorted);

// Takes about 6 seconds.

schwartzian-transform.php

<?php
function slowTransform($x) {
  // Access network, disk, calculate prime number or fibonacci.
  sleep(1);
  return $x * 2;
}

function sort_return($arr, $callable) {
  usort($arr, $callable);

  return $arr;
}

$unsorted = [3, 1, 6, 4, 2, 5];

$sorted = array_map(
  function ($x) { return $x[0]; },
  sort_return(
    array_map(
      function ($x) {
        return [$x, slowTransform($x)];
      },
      $unsorted
    ),
    function ($a, $b) use (&$seen) {
      return $a[1] - $b[1];
    }
  )
);

// Takes about 6s

short-functions-refactored.php

<?php
function social_post_form_post_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  // Show the users picture for new posts.
  if ($form_state->getFormObject()->getEntity()->isNew()) {
    $user_image = social_post_get_current_user_image();
    if ($user_image) {
      // Add to a new field, so twig can render it.
      $form['current_user_image'] = $user_image;
    }
  }
  // [Snip]
}

short-functions.php

<?php
function social_post_form_post_form_alter(&$form, FormStateInterface $form_state, $form_id) {
  // Show the users picture for new posts.
  if ($form_state->getFormObject()->getEntity()->isNew()) {
    // Load current user.
    $account = User::load(Drupal::currentUser()->id());
    // Load compact notification view mode of the attached profile.
    if ($account) {
      $storage = \Drupal::entityTypeManager()->getStorage('profile');
      if (!empty($storage)) {
        $user_profile = $storage->loadByUser($account, 'profile');
        if ($user_profile) {
          $content = \Drupal::entityTypeManager()->getViewBuilder('profile')
            ->view($user_profile, 'compact_notification');
          // Add to a new field, so twig can render it.
          $form['current_user_image'] = $content;
        }
      }
    }
  }

  // [Snip]
}

simple-match.rs

let x = 1;

match x {
    1 => println!("one"),
    2 => println!("two"),
    3 => println!("three"),
    _ => println!("anything"),
}

// Source: https://doc.rust-lang.org/1.5.0/book/patterns.html

simple-switch.js

const x = 3;

switch (x) {
  case 1:
    console.log("one");
    break;
  case 2:
    console.log("two");
    break;
  case 3:
    console.log("three");
    break;
  default:
    console.log("anything");
}

simple-switch.php

<?php
switch ($x) {
  case 1:
    echo "one";
    break;
  case 2:
    echo "two";
    break;
  case 3:
    echo "three";
    break;
  default:
    echo "anything";
}

TypeHintsExample-strict.php

<?php
// Required to actually trigger type errors.
declare(strict_types = 1);

/* An example of PHP 7.4's type hints. */
class TypeHintsExample {
  protected string $chant = 'We should come up with a chant!';

  public function setChant(string $newChant) {
    $this->chant = $newChant;
  }

  public function chant() {
    echo $this->chant . PHP_EOL;
  }

  public function isAwesome() : bool {
    return true;
  }
}

$fan = new TypeHintsExample();
$fan->setChant('PHP is improving!');

// Outputs: "PHP is improving!\n"
$fan->chant();

// Throws a TypeError
$fan->setChant(9001);

$fan->chant();

TypeHintsExample.php

<?php



/* An example of PHP 7.4's type hints. */
class TypeHintsExample {
  protected string $chant = 'We should come up with a chant!';

  public function setChant(string $newChant) {
    $this->chant = $newChant;
  }

  public function chant() {
    echo $this->chant . PHP_EOL;
  }

  public function isAwesome() : bool {
    return true;
  }
}

$fan = new TypeHintsExample();
$fan->setChant('PHP is improving!');

// Outputs: "PHP is improving!\n"
$fan->chant();


$fan->setChant(9001);
// Outputs: "9001\n"
$fan->chant();