Fast and simple datetime, date, time and duration parsing for rust.
speedate is a lax† RFC 3339 date and time parser, in other words, it parses common ISO 8601 formats.
† - all relaxations of from RFC 3339 compliant with ISO 8601.
The following formats are supported:
* Date: YYYY-MM-DD
* Time: HH:MM:SS
* Time: HH:MM:SS.FFFFFF 1 to 6 digits are allowed
* Time: HH:MM
* Date time: YYYY-MM-DDTHH:MM:SS - all the above time formats are allowed for the time part
* Date time: YYYY-MM-DD HH:MM:SS - T, t, and _ are allowed as separators
* Date time: YYYY-MM-DDTHH:MM:SSZ - Z or z is allowed as timezone
* Date time: YYYY-MM-DDTHH:MM:SS+08:00- positive and negative timezone are allowed, as per ISO 8601, U+2212 minus −
is allowed as well as ascii minus - (U+002D)
* Date time: YYYY-MM-DDTHH:MM:SS+0800 - the colon (:) in the timezone is optional
* Duration: PnYnMnDTnHnMnS - ISO 8601 duration format,
see wikipedia for more details, W for weeks is also allowed
* Duration: HH:MM:SS - any of the above time formats are allowed to represent a duration
* Duration: D days, HH:MM:SS - time prefixed by X days, case-insensitive, spaces s and , are all optional
* Duration: D d, HH:MM:SS - time prefixed by X d, case-insensitive, spaces and , are optional
* Duration: ±... - all duration formats shown here can be prefixed with + or - to indicate
positive and negative durations respectively
This will be the datetime parsing logic for pydantic-core.
```rust use speedate::{DateTime, Date, Time};
fn main() { let dt = DateTime::parsestr("2022-01-01T12:13:14Z").unwrap(); asserteq!( dt, DateTime { date: Date { year: 2022, month: 1, day: 1, }, time: Time { hour: 12, minute: 13, second: 14, microsecond: 0, }, offset: Some(0), } ); asserteq!(dt.tostring(), "2022-01-01T12:13:14Z"); } ```
speedate is significantly faster than
chrono's parse_from_rfc3339
and iso8601.
Micro-benchmarking from benches/main.rs:
text
test compare_dt_error_chrono ... bench: 192 ns/iter (+/- 0)
test compare_dt_error_iso8601 ... bench: 462 ns/iter (+/- 4)
test compare_dt_error_speedate ... bench: 26 ns/iter (+/- 0)
test compare_dt_ok_chrono ... bench: 250 ns/iter (+/- 1)
test compare_dt_ok_iso8601 ... bench: 323 ns/iter (+/- 1)
test compare_dt_ok_speedate ... bench: 36 ns/iter (+/- 0)
ISO8601 has lots of allowed formats, see ijmacd.github.io/rfc3339-iso8601.
Most of these are unknown to most users, and not desired. This library aims to support the most common formats without introducing ambiguity.