DEV Community

Cover image for An emoji dictionary in Svelte
Bryce Dorn
Bryce Dorn

Posted on • Updated on

An emoji dictionary in Svelte

As an avid user of the πŸ…±οΈ emoji, I get (too much) enjoyment out of the few alphabetical characters in the emoji alphabet.

But we can do more than just substitute a b with a πŸ…±οΈ; I wanted to know many words can be written entirely with emoji. Let's find out!

First I found an (English) dictionary and wrote a quick & dirty Rust script to generate the words. Just a list of words isn't fun though, it needs interactivity! I chose Svelte for this to get some hands-on with its dev experience (it's pretty good!) and performance.

To start, I made a basic webpack config with svelte-loader and three files:

Note: if you want to skip to the end, the source is here.
  • index.html, with a <body> where the Svelte app will be mounted to (just like ReactDOM)
  • main.js, where the app is mounted & passed props
  • App.svelte, for the component & filtering logic


In main.js, the words are imported and prepared for the component:

import words from 'output.txt';

// Associate letters & sequences with their 
// emoji equivalents
const emojiHash = {
    "id": "πŸ†”",
    "a": "πŸ…°οΈ",
    "soon": "πŸ”œ"

// Replace the letters/sequences in a string as 
// their respective emoji
const convertToEmoji = (word) => {
    let emojified = String(word);
    regexKeys.forEach((key, i) => {
        emojified = emojified.replace(key, emojiHash[sortedKeys[i]];
    return emojified;

// Render letters/sequences as emoji by running 
// the above function until there are no letters
// remaining
function emojify(word) {
    let emojified = String(word);
    do {
        emojified = convertToEmoji(emojified);
    } while (emojified.split('').some(e => /^[a-zA-Z]+$/.test(e)));
    return emojified;

Enter fullscreen mode Exit fullscreen mode

Then the component is mounted to the DOM:

const app = new App({
    target: document.body,
    props: {
        emoji: Object.values(emojiHash),
        sort: 'default',
        words: words.split('\n').map(emojify)
Enter fullscreen mode Exit fullscreen mode


Great! Now we have formatted data coming into the component, let's do something with it.

*.svelte files are HTML files with some syntactic sugar. The basic structure is as follows:

  // Functions, variables
  export let words;

  function clicky(e) {

<!-- Any styles associated with the component -->
  .container { 
    background: palevioletred; 

<!-- The rendered markup -->
<div class="container">
    {#each words as word}
        <p on:click={clicky}>
Enter fullscreen mode Exit fullscreen mode

πŸŽ‰ ta-da! πŸŽ‰ A list of words rendered with Svelte! Note that since words is being passed in as a prop, the export keyword is needed.

For the sake of brevity I'll just go through adding filtering (sorting is in the repo if you want to take a look).

Somewhere in the component, let's render a list of checkboxes for each emoji:

{#each emoji as moji}
    <input on:change={handleFilterClick} type="checkbox" checked={!filteredEmoji.includes(moji)} value={moji}>
Enter fullscreen mode Exit fullscreen mode

Since we're rendering the list via the words variable, we'll need to update it to reflect the filter.

  export let words;

  // Keep an immutable version of words in memory
  export let wordsImm = Array.from(words);

  function handleFilterClick(e) {
    const { checked, value } =;

    // Keep immutable version of original prop & make a copy 
    // to apply filters to
    let wordsMut = Array.from(wordsImm);

    // Either add or remove the current emoji from the filters
    if (checked) {
      filteredEmoji.splice(filteredEmoji.indexOf(value), 1);
    } else {

    // If there are filters, apply them to list of words
    if (filteredEmoji.length > 0) {
      filteredEmoji.forEach(emoji => {
        wordsMut = wordsMut.filter(word => !word.includes(emoji));

    // Set variable to new list
    words = wordsMut;
Enter fullscreen mode Exit fullscreen mode

When words is updated to the filtered (mutated) version after selecting a filter, it will trigger an update and the DOM will render the new list.

Side-note: this could be refactored to have the filtering in the `{each}`, (preventing the need to update `words`) but I wanted to render the number of words in a different part of the component.

Final thoughts

Svelte is nice & fast! I plan to use it again, ideally for something more resource intensive/visually demanding to really push it to its limits (beyond where React would have issues).

I also want to see how it is to work on a larger project using Sapper, once the framework is more mature.

Go play with it here!

View source on Github.

Top comments (3)

deciduously profile image
Ben Lovy

I think I hate this, but I also think I love this. Nice work?

Svelte looks cooler by the day.

bryce profile image
Bryce Dorn

Haha πŸ‘» it's getting better! Still a ways away from the clarity of React.

deciduously profile image
Ben Lovy

Yeah, but "clarity" is a complicated term, right? The sales pitch of compiling away the framework entirely is too cool to dismiss outright. React often feels like overengineering for a given problem, Svelte gets you a lot of the benefit without so much overhead.