module PhcStringFormat

PHC string format implemented by Ruby

```
$<id>[$<param>=<value>(,<param>=<value>)*][$<salt>[$<hash>]]
```

See:

• github.com/P-H-C/phc-string-format/blob/master/phc-sf-spec.md

• github.com/P-H-C/phc-string-format/pull/4