😍🐘pg-emoji

1. About
2. Dependencies
3. Installation
4. Usage
5. API
   1. emoji.encode(bytea)→text
   2. emoji.decode(text)→bytea
   3. emoji.from_text(text)→text
   4. emoji.to_text(text)→text

1. About

emoji is a pure SQL PostgreSQL extension to encode/decode bytea/text to/from emoji.

A lookup-table is constructed from the first 1024 emojis from [https://unicode.org/Public/emoji/13.1/emoji-test.txt], where each emoji maps to a unique 10 bit sequence.

The input data is split into 10 bit fragments, mapped to the corresponding emojis.

The first emoji in the result is a header, where the first bit is 1 if the result was zero padded, and the remaining 9 bits is a checksum based on the input data.

If the checksum is invalid during decode, NULL is returned.

2. Dependencies

None.

3. Installation

Install the emoji extension with:

$ git clone https://github.com/truthly/pg-emoji.git
$ cd pg-emoji
$ make
$ sudo make install
$ make installcheck

4. Usage

Use with:

$ psql
# CREATE EXTENSION emoji;
CREATE EXTENSION;

5. API

emoji.encode(bytea)→text

SELECT emoji.encode('\x0123456789abcdef'::bytea);
  encode
----------
 👦😀🥺🪀🦠🖖🌌🥚
(1 row)

Making a subtle change to the input data will not only change the corresponding emoji, but also the first emoji which contains a 9-bit checksum of the data, which means it will change with 99.8% confidence (511/512). Notice in the example below what happens if the last f is changed to 7.

SELECT emoji.encode('\x0123458789abcde7'::bytea);
  encode
----------
 💜😀🥺🪀🍼🖖🌌🍕
(1 row)

emoji.decode(text)→bytea

SELECT emoji.decode('👦😀🥺🪀🦠🖖🌌🥚');
       decode
--------------------
 \x0123456789abcdef
(1 row)

Thanks to the first emoji containing a 9-bit checksum of the data, failing to properly copy/paste the entire emoji string will be detected upon decoding with 99.8% confidence and NULL will be returned.

SELECT emoji.decode('👦😀🥺🪀🦠🖖🌌');
 decode
--------

(1 row)

emoji.from_text(text)→text

SELECT emoji.from_text('Hello 🌎!');
 from_text
------------
 🦳🥺🐞🕰🎐🎗📷🧂🎖🫖
(1 row)

emoji.to_text(text)→text

SELECT emoji.to_text('🦳🥺🐞🕰🎐🎗📷🧂🎖🫖');
 to_text
----------
 Hello 🌎!
(1 row)