Retrieving words with colon, and associated data - php

Question

I have data formatted as such:
some words go here priority: p1,p2 -rank:3 status: not delayed
Basically I need to retrieve each set of data that corresponds to the colon name.
Ideally if I could end up with an array structure such that
keywords => 'some words go here'
priority => 'p1,p2'
-rank => 3
status => 'not delayed'
A few caveats:
keywords will not have a defining colon-word (keywords are just placed in the front)
keywords will not always exist (might just be colon-words)
colon-words will not always exist (might just be keywords)
I imagine regex will have to be used to parse this out, but this goes beyond my understanding of regex.
If there is a simpler approach to this I'd be happy to find out.
Any help appreciated!

Answer 1

A regular expression will certainly be a much more elegant approach to this as #HamZa showed, but here's a proof of concept to illustrate that you could just brute force the solution. Keep in mind, this is a proof of concept, I won't be doing your entire assignment for you ;)
<?php
$string = "keywords go here priority: p1,p2 -rank:3 status: not delayed";
$kv = array();
$key = "keywords";
$substrings = explode(":", $string);
foreach($substrings as $k => $substring) {
$pieces = explode(" ", $substring);
$chunk = $k == count($substrings) - 1 ? 0 : 1;
$kv[$key] = trim(join(" ", array_slice($pieces, 0, count($pieces)-$chunk)));
$key = $pieces[count($pieces)-1];
}
print_r($kv);
// Array
// (
// [keywords] => keywords go here
// [priority] => p1,p2
// [-rank] => 3
// [status] => not delayed
// )