Function percent_encode 

pub fn percent_encode(input: &str) -> String

Percent-encode a string for use in a URL query component. Unreserved characters (A-Z a-z 0-9 - _ . ~, per RFC 3986) pass through; every other byte becomes %XX.

Public because the script provider engine registers the same encode_uri host function and had a byte-identical copy of this. Two encoders that scripts reach by the same name is a difference waiting to be discovered by whoever writes a .rhai that works in one and not the other.