Module:Emoji/doc

Module:Emoji implements two functions:
 * emocode : Takes one unnamed parameter, the name of the emoji, and returns the hex code for the corresponding emoji. If no name is supplied it uses "smiley" as the default (and returns ).
 * emoname : Takes one unnamed parameter, the hex code of the emoji, and returns the name for the corresponding emoji. If no name is supplied it uses "1f603" as the default (and returns ).

It stores the mapping from name to code in Module:Emoji/data, which internally generates the reverse lookup table from code to name.