Adds support for aliases

[mislav]

require 'emoji/aliases'
Emoji.aliases_for('smile') #=> [...]

The use-case is to enhance the completion suggester for entering emojis.

This initial set of aliases is inspired by @muan's emojis.json.

This is 🚧 🚧 since there are a couple of open questions:

• Is it OK to keep the list in YAML? It could be a plain text file just as well. I only want to keep it line-based for easier editing & diffs.
• Is it useful that this is an optional require, or should it come by default when you require (g)emoji?
• There is already a scheme for aliasing via symlinks. The following emojis already had multiple names:

	names	Unicode description
😆	laughing, satisfied	smiling face with open mouth and tightly-closed eyes
💩	hankey, poop, shit	pile of poo
💥	boom, collision	collision symbol
👍	+1, thumbsup	thumbs up sign
👎	-1, thumbsdown	thumbs down sign
👊	facepunch, punch	fisted hand sign
✋	hand, raised_hand	raised hand
🏃	runner, running	runner
👞	mans_shoe, shoe	mans shoe
👕	shirt, tshirt	t-shirt
🐝	bee, honeybee	honeybee
🐬	dolphin, flipper	dolphin
🐾	feet, paw_prints	paw prints
🌔	moon, waxing_gibbous_moon	waxing gibbous moon symbol
☎️	phone, telephone	black telephone
🔪	hocho, knife	hocho
📧	email, envelope	envelope
📝	memo, pencil	memo
📖	book, open_book	open book
⛵	boat, sailboat	sailboat
🚗	car, red_car	automobile
🏮	izakaya_lantern, lantern	izakaya lantern
🇬🇧	gb, uk	regional indicator symbol letter g + b
❗	exclamation, heavy_exclamation_mark	heavy exclamation mark symbol

This PR adds another scheme for aliasing, and now we end up with 2 levels of aliasing, which I don't like. I would prefer to get rid of multiple aliases on the filesystem and just go the route with aliases kept in a data file. However, if we delete the filesystem aliases then we break backwards compatibility, since people might be using :knife: in their textareas and knife.png in their apps.

[josh]

Is it useful that this is an optional require, or should it come by default when you require (g)emoji?

It should be in the standard require.

This PR adds another scheme for aliasing, and now we end up with 2 levels of aliasing, which I don't like. I would prefer to get rid of multiple aliases on the filesystem and just go the route with aliases kept in a data file.

I kinda like not normalizing to a canonical name. That requires the use of a suggester. I'd rather have literal :toilet: and :wc syntaxes both work.

We currently have a issue with the symlinks we might need to work out first. When the gem is built, symlinks get stripped. So we might need to move to a data file anyway.

[josh]

/cc @trevorturk @aroben @javan @asianmack

[javan]

👍 to killing all the symlinked files. The gem should just contain the images in unicode/.

If the data file mapped each unicode to an array of names ({ "1f4a9" => ["poop", "shit"] }), we'd be all set. The first name in the array could be considered "canonical", but it wouldn't matter.

The install task could then create all the symlinks.

[mislav]

Here's the difference right now with "names" vs. "aliases":

1. "Names" have a corresponding image and are a valid argument for Emoji.unicode_for(name). A single emoji can have multiple names (illustrated by the table above).
2. "Aliases" don't have a corresponding image and are not a valid argument for Emoji.unicode_for(alias).

This creates 2 different vectors for referring to a single emoji. I don't like that, and even before this PR I didn't like the symlink style:

1. People end up with multiple png images (hankey, poop, shit) representing the same emoji.
2. Png images named with unicode codepoints also get copied to people's project, but people don't know what to do with them.
3. Not all emoji from this gem resolve to some unicode codepoints; there are a few custom emoji that are not part of Unicode.

I think I'll open a separate PR to first propose how I would get rid of symlinks. Adding aliases to the current situation would just be confusing.

[josh]

I think I'll open a separate PR to first propose how I would get rid of symlinks. Adding aliases to the current situation would just be confusing.

Rad.

[javan]

🤘

[mislav]

Closing this; going with #47 instead