RFC822/2822_sanitizer

A helper funtion trying to fix invalid rfc822/2822 inputs

The world is a mess and everyone seem to reinvent daytimes.

This crates soul purpose is to try to fix the those generators that do stuff like this:

Thu, 05 Aug 2016 06:00:00 -0400

Mon, 31 July 2017 16:00:00 PDT

Wed, 20 Sep 2017 10:00:00 -0000

30 Aug 2017 1:30:00 PDT

All of the above look fine at first glance. But all are invalid and would fail to be parsed with chrono::Datetime::parse_from_rfc2822

Playground link.

Err(ParseError(Impossible)) Err(ParseError(Invalid)) Err(ParseError(NotEnough)) Err(ParseError(Invalid))

• The first one Thu, 05 Aug 2016 06:00:00 -0400 is actually a Friday.

• The second Mon, 31 July 2017 16:00:00 PDT uses full lenght month Name.

• The third Wed, 20 Sep 2017 10:00:00 -0000 has -0000 as the timezone, which is sort of undefined behaviour. For more see #102.

• The forth 30 Aug 2017 1:30:00 PDT uses single digit notation for Hour.

The dates above have been encountered while trying to parse rss feeds from the wild west eer A Internet.

The RSS spec specifies the use of RFC822 for the date format, which is forward compatible with RFC2822. This crate proves that people/generators still get wrong a format witch was published in 1982.

Now if we were to use the sanitizer, we would actually get a correct datetime.

Usage:

Add the following to your Cargo.toml. [dependencies] chrono = "0.4"

from examples/simple.rs

``` extern crate rfc822sanitizer; use rfc822sanitizer::parsefromrfc2822withfallback;

fn main() { let dates = vec![ "Thu, 05 Aug 2016 06:00:00 -0400", "Mon, 31 July 2017 16:00:00 PDT", "Wed, 20 Sep 2017 10:00:00 -0000", "30 Aug 2017 1:30:00 PDT", ];

for foo in dates.iter() {
    let fallback = parse_from_rfc2822_with_fallback(&foo);
    println!("{:?}", fallback);
}

} ```

Output: Ok(2016-08-05T06:00:00-04:00) Ok(2017-07-31T16:00:00-07:00) Ok(2017-09-20T10:00:00+00:00) Ok(2017-08-30T01:30:00-07:00)

Though keep in mind that it would consume more resources.

Some Optimizations are on the way.

$ cargo bench -q running 4 tests test tests::test_invalid_dates ... ignored test tests::bench_correct_dates_normal_parse ... bench: 20,958 ns/iter (+/- 561) test tests::bench_correct_dates_with_fallback ... bench: 21,299 ns/iter (+/- 587) test tests::bench_parse_invalid_dates_with_fallback ... bench: 16,232,542 ns/iter (+/- 314,063)