Cookbook ideas for chrono

[j-haj]

Let's add some recipes for the chrono crate. Feel free to contribute additional examples/ideas or PRs!

• Display formatted date and time using RFC 2822, RFC 3339, and custom formats
• Create a DateTime struct from input using RFC 2822, RFC 3339, and custom formats
• Example showing checked arithmetic using dates
• Example showing use of functions from the Datelike and Timelike traits such as month, weekday, hour, minute, etc.

[budziq]

Initial ideas by @j-haj
Here are some ideas to start us off:

• Display formatted date and time using RFC 2822, RFC 3339, and custom formats
• Create a DateTime struct from input using RFC 2822, RFC 3339, and custom formats
• Example showing checked arithmetic using dates
• Example showing use of functions from the Datelike and Timelike traits such as month, weekday, hour, minute, etc.
• Example showing serialization and deserialization of DateTime using serde Id avoid that example for now as it requires a nondefault crate feature (explicitly enabling "serde" in cargo toml) Lets put it on back-burner for now #324 (comment)

Once we get some attention here, I'll stsrt adding final example ideas to the tracking list.

Thanks a lot @j-haj ! 🥇

[hegza]

I've done something like what you're describing here @budziq / @j-haj, for both formatting and clocking execution time. Could be cool trying to make them as idiomatic as I can. I believe I'll be able to get back to you with a PR about the three first points later down the week.

[j-haj]

@hegza Sounds great - can't wait to see the examples!

One thing I noticed the other day is that chrono seems to state that it is not really best used for tracking elapsed time to execute a segment of code:

For more abstract moment-in-time tracking such as internal timekeeping that is unconcerned with timezones, consider time::SystemTime, which tracks your system clock, or time::Instant, which is an opaque but monotonically-increasing representation of a moment in time.

I'm wondering if maybe the first item in our list should be removed. @budziq what are your thoughts?

[hegza]

Seems so. I would agree with just skipping that first one, since it would be hardly idiomatic to do something that the crate is not supposed to do.

Another question I had in mind was that if the chrono examples should be assigned under some one of the current top-level topics, or if it should be a new topic. It seems that the topics are not trying to be library-by-library, but rather something more abstract. Formatting date-time could certainly be situated in more than just one of the current topics.

[j-haj]

Another question I had in mind was that if the chrono examples should be assigned under some one of the current top-level topics, or if it should be a new topic.

Excellent question. Probably something for @budziq to chime in on but my intuition is that it makes the most sense to add this to basics section. It may not be super important as it sounds like we may reorganize things in the future.

[budziq]

@j-haj & @hegza

I'm wondering if maybe the first item in our list should be removed. @budziq what are your thoughts?

Yep this item is a viable example idea but would be std only 👍 - I'll add it to misc/std tracking issue.

Another question I had in mind was that if the chrono examples should be assigned under some one of the current top-level topics, or if it should be a new topic.

Aaron is working on an editorial pass over the cookbook examples including section reorganization. For now lets add it to basics as @j-haj suggests.

[budziq]

Example showing serialization and deserialization of DateTime using serde

For now such example would require a nondefault crate feature (explicitly enabling "serde" in cargo toml). As we have no clear story yet on howto support cargo features (how do we test these, how do we present cargo.toml and how to handle desynchronization with https://play.rust-lang.org/ which does not support crate features) Lets put it on back-burner for now

[ludwigpacifici]

Two additional examples:

• For a given timezone, convert a local time to UTC and convert UTC time to local time.
• Convert a formatted date (for example YYYY-MM-DD:HH:MM:SS) to a Unix timestamp. Convert it also the other way around.

Do you think these could be interesting recipes? If you are happy with it, I can open dedicated issues for them.

[budziq]

@ludwigpacifici

Do you think these could be interesting recipes?

Very cool ideas! Lets go for it 👍

[AndyGauge]

As all the proposed ideas are implemented, I'm going to close the tracking issue. If you have additional ideas for Chrono, please feel free to open a new issue. The one outstanding issue mentioned is reorganization. That is definitely in the works.