bspeice/dtparse

Supports microsecond precision, but doesn't support nanoseconds

Closed this issue · 3 comments

bobhy commented

Not a bug report, it's a feature request.

Crate chrono supports datetime with nanosecond precision, but dtparse appears to support "only" microseconds. We use dtparse in nushell, but it's silently truncating user input.

use chrono::prelude::*;
use dtparse::parse;

fn main() {
    assert_eq!(
        parse("2008.12.29T08:09:10.123456789").unwrap(),
        (
            NaiveDate::from_ymd_opt(2008, 12, 29)
                .unwrap()
                .and_hms_nano_opt(8, 9, 10, 123_456_789)
                .unwrap(),
            None
        )
    );
}

produces:

Compiling work v0.1.0 (/home/bobhy/src/rust/work)
    Finished dev [unoptimized + debuginfo] target(s) in 0.50s
     Running `target/debug/work`
thread 'main' panicked at 'assertion failed: `(left == right)`
  left: `(2008-12-29T08:09:10.123456, None)`,
 right: `(2008-12-29T08:09:10.123456789, None)`', src/main.rs:5:5
stack backtrace:
   0: rust_begin_unwind
             at /rustc/90743e7298aca107ddaa0c202a4d3604e29bfeb6/library/std/src/panicking.rs:575:5
   1: core::panicking::panic_fmt
             at /rustc/90743e7298aca107ddaa0c202a4d3604e29bfeb6/library/core/src/panicking.rs:65:14
--- clip ---

Note dtparse simply truncated the sub-microsecond nanosecond bits that were specified in the call to dtparse().

bspeice commented

Took a quick look, I think the change would need to fix two things:

  1. Micros are currently i32, needs to be i64 to support the full range
  2. Parser::parsems explicitly slices 6 characters from the text, needs to allow 9

Should be able to implement that in the near future.

bspeice commented

Bit delayed on it, but I was correct that it was a fairly simple change. Nanoseconds now supported, and released as 1.4.0. Let me know if you need anything else!

bobhy commented