[WIP] feat(std): add time module to standard library

[Etherian]

Description

Adds a time module to the standard library which exposes the functionality of Rust's std::time.

Status

In Development

Outstanding design questions

• How should std.time be structured -- std.time.Instant.now, std.time.instant_now, std.instant.now, or something else? (std.time.Instant.now)
• Should std.time be behind a feature? Should that feature be default? (not behind feature)

To Do

• Implement all functionality in std::time
  • Implement types
  • Implement functions
  • Implement implicit interfaces (Eq and Ord)
• Add documentation
  • Generated std lib docs
  • Examples
  • In Rust code? (no need)
• Add tests (no need)

Future Directions

• add duration.from_secs_float, duration.as_secs_float, duration.mul_float, and duration.div_float
• Add more full-featured date-and-time functionality to the standard library? Chrono?

[Etherian]

Here's my rough draft of a std.time module. Structurally, I'm leaning towards each of the three types getting their own namespace -- e.g. std.time.Instant.now or std.time.Duration.checked_sub.

For now, I'm stuck on an error that occurs when I attempt to import std.time.

> .\target\debug\gluon.exe -i
gluon (:h for help, :q to quit)
> let time = import! std.time
error: error: Userdata cannot be cloned
- <std.time>:3:20
  |
3 | let time = import! std.time.prim
  |                    ^^^^^^^^^^^^^
  |

Any suggestions?

[Marwes]

Here's my rough draft of a std.time module. Structurally, I'm leaning towards each of the three types getting their own namespace -- e.g. std.time.Instant.now or std.time.Duration.checked_sub.

👍 std.time.duration.checked_sub etc

[Marwes]

Should std.time be behind a feature? Should that feature be default?

I don't think a feature is warranted for modules mirroring rusts std library. If we end up seeing that gluon's standard library is to large at some point it could be investigated then.

[Etherian]

Adding #[gluon_userdata(clone)] caused a couple errors.

error[E0053]: method `deep_clone` has an incompatible type for trait
  --> src\std_lib\time.rs:16:24
   |
16 | #[derive(Clone, Debug, Userdata, Trace, VmType)]
   |                        ^^^^^^^^ expected struct `vm::gc::Borrow`, found struct `vm::gc::GcPtr`
   |
   = note: expected type `fn(&std_lib::time::Duration, &'gc mut vm::api::Cloner<'_>) -> std::result::Result<vm::gc::Borrow<'gc, vm::gc::GcPtr<std::boxed::Box<(dyn vm::api::Userdata + 'static)>>>, vm::Error>`
              found type `fn(&std_lib::time::Duration, &mut vm::api::Cloner<'_>) -> std::result::Result<vm::gc::GcPtr<std::boxed::Box<(dyn vm::api::Userdata + 'static)>>, vm::Error>`

error[E0308]: mismatched types
  --> src\std_lib\time.rs:16:24
   |
16 | #[derive(Clone, Debug, Userdata, Trace, VmType)]
   |                        ^^^^^^^^
   |                        |
   |                        expected struct `vm::gc::GcPtr`, found struct `vm::gc::Borrow`
   |                        expected `std::result::Result<vm::gc::GcPtr<std::boxed::Box<(dyn vm::api::Userdata + 'static)>>, vm::Error>` because of return type
   |
   = note: expected type `std::result::Result<vm::gc::GcPtr<std::boxed::Box<(dyn vm::api::Userdata + 'static)>>, _>`
              found type `std::result::Result<vm::gc::Borrow<'_, vm::gc::GcPtr<std::boxed::Box<dyn vm::api::Userdata>>, >, _>`

[Etherian]

Could you mentor me regarding tests for this module? I don't have much experience writing tests and I am not confident I can write them correctly and thoroughly. Maybe you could give me examples or an outline of what properties to test and how to test those properties?

Also, how do I include documentation for external types and values?

[Marwes]

Since this is mostly just exposing functions defined and tested by rust itself I don't think the testing needs to be so thorough. Having some examples like in https://doc.rust-lang.org/std/time/struct.Duration.html would be good though.

There isn't a way to define documentation in rust code so you will need to define it in the gluon module

/// Docs
let new = prim.new
{
    new,
    /// Docs
    checked_sub = prim.checked_sub,
    ....
}

Doc tests require some unfortunate boilerplate atm, but you can look at the json module for how they are done

gluon/std/json/de.glu

Lines 67 to 77 in a507ed0

	/// Deserializes a `Bool`
	///
	/// ```
	/// let { ? } = import! std.effect
	/// let { Value, bool, deserialize_with } = import! std.json.de
	/// let { Result, ? } = import! std.result
	/// let { assert_eq, ? } = import! std.test
	///
	/// seq assert_eq (deserialize_with bool "true") (Ok True)
	/// assert_eq (deserialize_with bool "123") (Err "Expected bool")
	/// ```

[Etherian]

I finally got around to finishing the doc comments for std.time. Is there a way I can test the examples without running the whole doc test suite?

[Marwes]

cargo test --test main --features test -- @time should only compile and run tests for modules matching time

[Etherian]

It looks like doc comments are not currently recognized on record entries, which is where I have placed my docs for the time modules. Could this behavior be added, and/or should I restructure my gluon files so doc comments are all attached to let bindings?

[Marwes]

#870

[Etherian]

I'm running into a few errors while testing the examples.

---

This line in some examples

let dur_show : Show duration.Duration = { show = \_ -> "<duration>" }

seems to cause the following error:

thread 'tokio-runtime-worker' panicked at 'Lambda without source location. Please report an issue at https://github.com/gluon-lang/gluon/issues', check\src\rename.rs:246:94

Replacing the lambdas with const fixed these errors.

---

Various other errors occur unpredictably. In fact, one time all the tests passed without any of these errors. I don't have any guesses as to why they are occurring.

thread 'tokio-runtime-worker' panicked at 'assertion failed: `(left == right)`
  left: `7`,
 right: `3`', vm\src\stack.rs:579:9

thread 'tokio-runtime-worker' panicked at 'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"', vm\src\thread.rs:1143:22

thread 'tokio-runtime-worker' panicked at 'Attempted to pop Frame { offset: 22, state: Extern(ExternState { function: std.time.prim.system_time.duration_since 0x5dcb40, call_state: Poll, locked: None }), excess: false } but std.time.prim.system_time.now was expected

thread 'tokio-runtime-worker' panicked at 'Expected extern: Closure(ClosureState { closure: ClosureData { function: 0x12cc4750:wrap@38_5, upvars: [] }, instruction_index: 0 }). Please report an issue at https://github.com/gluon-lang/gluon/issues', vm\src\stack.rs:251:18

thread ':tokio-runtime-worker' panicked at ':ValueRef is not an Userdata: Int(0). Please report an issue at https://github.com/gluon-lang/gluon/issues', <rustlib>/src/rust\src\libstd\macros.rs:16:9

---

Full output of a test run

> cargo test --test main --features test time
    Finished test [unoptimized + debuginfo] target(s) in 1.33s
     Running target\debug\deps\main-79fe047da3eb48b4.exe
main
        doc
                std.time.duration
                        Duration ... ok
                        new ... ok
                        from_secs ... ok
                        from_millis ... ok
                        from_micros ... ok
                        from_nanos ... ok
                        as_secs ... ok
                        subsec_millis ... ok
                        subsec_micros ... ok
                        subsec_nanos ... ok
                        as_millis ... ok
                        as_micros ... thread 'tokio-runtime-workerok' panicked at '
Expected extern: Closure(ClosureState { closure: ClosureData { function: 0x1438a1d0:assert_some@59_5, upvars: [<0x12d29420:wrap@38_5 0x141afa28>, {2147483648: {2147483648: <0x12d84980:std.effect.functor@35_11 0x142b1a28>}, {2147483648: {2147483648: <0x12d84980:std.effect.functor@35_11 0x142b1a
                        as_nanos ... 28>}, <0x1413ddc0:std.effect.applicative@40_13 0x142b1d28>, <0x14088e80:wrap_eff@28_5 0x142b1728>}, {2147483648: {2147483648: {2147483648: }, <0x1413ddc0:std.effect.applicative@40_13 0x142b1d28>, <0x14088e80:wrap_eff@28_5 0x142b1728>}, <0x14088ee0:flat_map_eff@29_5 0x142b1828>}, <0x13ed0020:ruokn_pure@56_5 0x142b1f28>, <0x13ed0000:inject_rest@51_5 0x142b1e28>}, <0x140fdb90:tell@22_5 0x14394ea8>] }, instruction_index: 0 }). Please report an issue at https://github.com/gluon-lang/gluon/issues
', vm\src\stack.rs                      checked_add ... :ok251
:18                     checked_sub ...
thread 'oktokio-runtime-workernote: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

' panicked at 'Attempted to pop Frame { offset: 22, state: Extern(ExternState { function: std.time.prim.system_time.duration_since 0x5dcb40, call_state: Poll, locked: None }), excess: false } but std.time.prim.system_time.now was expected                     checked_mul ... ', okvm\src\thread.rs
:1927                   checked_div ... :thread 'ok13tokio-runtime-worker

' panicked at 'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"
thread '', tokio-runtime-workervm\src\thread.rs         std.time.instant
' panicked at ':called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"1143                    Instant ... ', :okvm\src\thread.rs22
:
1143                    now ... :FAILED22

thread 'thread 'tokio-runtime-workerExpected extern: Closure(ClosureState { closure: ClosureData { function: 0x1438a1d0:assert_some@59_5, upvars: [<0x12d29420:wrap@38_5 0x141afa28>, {2147483648: {2147483648: <0x12d84980:std.effect.functor@35_11 0x142b1a28>}, {2147483648: {2147483648: <0x12d84980:std.effect.functor@35_11 tokio-runtime-worker' panicked at '0x142b1a28>}, <0x1413ddc0:std.effect.applicative@40_13 0x142b1d28>, <0x14088e80:wrap_eff@28_5 0x142b1728>}, {2147483648: {2147483648: {2147483648: }, <0x1413ddc0:std.effect.applicative@40_13 0x142b1d28>, <0x14088e80:wrap_eff@28_5 0x142b1728>}, <0x14088ee0:flat_map_eff@29_5 0x142b1828>}, <0x13e' panicked at 'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"d0020:run_pure@56_5 0x142b1f28>, <0x13ed0000:inject_rest@51_5 0x142b1e28>}, <0x140fdb90:tell@22_5 0x14394ea8>] }, instruction_index: 0 }). Please rcalled `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"', eport an issue at https://github.com/gluon-lang/gluon/issues', vm\src\thread.rs                      durvm\src\thread.rsation_since ... ::1143FAILED1143:
:2222

thread 'thread 'tokio-runtime-workercalled `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"tokio-runtime-worker' panicked at '
        saturating_duration_since ... ' pacalled `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"nicked at 'FAILED', called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"
vm\src\thread.rs', :GetOffset on <0x12d29420:wrap@38_5 0x141afa28>vm\src\thread.rs1143:                 elapsed ... :114322FAILED:

22thread '
tokio-runtime-worker' panicked at 'thread 'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"tokio-runtime-worker', ' panicked at 'vm\src\thread.rscalled `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }":1143', vm\src\thread.rs::221143:
22
thread 'called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"tokio-runtime-worker                    checked_add ... ' panicked FAILEDat '
called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"', vm\src\thread.rscalled `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }":                       checked_sub ... 1143:FAILED22

called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"
                std.time.system_time
                        unix_epoch ... FAILED
Attempted to pop Frame { offset: 22, state: Extern(ExternState { function: std.time.prim.system_time.duration_since 0x5dcb40, call_state: Poll, locked: None }), excess: false } but std.time.prim.system_time.now was expected                    now ... FAILED
called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"                        duration_since ... FAILED
called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"                        elapsed ... FAILED
called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"                        checked_add ... FAILED
called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"                        checked_sub ... FAILED
called `Result::unwrap()` on an `Err` value: "PoisonError { inner: .. }"


test result: FAILED. 18 passed; 12 failed; 175 filtered
Some tests failed
error: test failed, to rerun pass '--test main'

[Etherian]

@Marwes Have you had a chance to look at this?

[Marwes]

Sorry, no. Haven't had that much motivation to code outside of work lately. Won't have time over the weekend either but I will try to look at it next week.

[Etherian]

Sure. No rush. 🙂

[Etherian]

The good news is no conflicts have cropped up. The bad news is that it's still throwing errors I don't know how to solve. Do you have time to take a look, @Marwes?