Enable autocomplete or intellisense in Atom editor for PHP -

i'm first time user of atom editor php code. atom can autocomplete built-in functions of php. possible make editor autocomplete custom function written in separate file?

function.php

<?php function printsomething() {    echo "hello world"; } 

index.php

<?php require_once "function.php"; printsomething(); // autocompleted atom editor while typing 

thanks in advance.

there text file in %userprofile%.atom called snippets.cson. in there can add snippet.

more this: http://flight-manual.atom.io/using-atom/sections/snippets/

but need think can use later on other files well. otherwise need copy , paste.