revset: create TimeExpression type

Creates a TimeExpression type that can be created by parsing a string in any
format supported by the chrono-english crate, including:

- 2024-03-25
- 2024-03-25T00:00:00
- 2024-03-25T00:00:00-08:00
- 2 weeks ago
- 5 minutes ago
- yesterday
- yesterday 5pm
- yesterday 10:30
- yesterday 15:30
- tomorrow

chrono-english supports US and UK dialects to disambiguate mm/dd/yy from
dd/mm/yy, but for now we default to US. This should probably be a config
setting.

Cargo.toml

@@ -39,6 +39,7 @@ chrono = { version = "0.4.38", default-features = false, features = [
     "std",
     "clock",
 ] }
+chrono-english = { version = "0.1.7" }
 config = { version = "0.13.4", default-features = false, features = ["toml"] }
 criterion = "0.5.1"
 crossterm = { version = "0.27", default-features = false }

lib/Cargo.toml

@@ -38,6 +38,7 @@ backoff = { workspace = true }
 blake2 = { workspace = true }
 bytes = { workspace = true }
 chrono = { workspace = true }
+chrono-english = { workspace = true }
 config = { workspace = true }
 digest = { workspace = true }
 either = { workspace = true }

lib/src/lib.rs

@@ -84,6 +84,7 @@ pub mod stacked_table;
 pub mod store;
 pub mod str_util;
 pub mod submodule_store;
+pub mod time_expression;
 pub mod transaction;
 pub mod tree;
 pub mod tree_builder;

lib/src/time_expression.rs

@@ -0,0 +1,111 @@
+// Copyright 2024 The Jujutsu Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Provides a TimeExpression type that represents a range of time.
+
+use chrono::{DateTime, TimeZone};
+use chrono_english::{parse_date_string, DateError, Dialect};
+
+use crate::backend::Timestamp;
+
+/// Represents an expression to match dates and times.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum TimeExpression {
+    /// Represents all times at or after the given instant in time.
+    AtOrAfter(Timestamp),
+}
+
+impl TimeExpression {
+    /// Parses a string into a TimeExpression.
+    pub fn parse<Tz: TimeZone>(s: &str, now: DateTime<Tz>) -> Result<TimeExpression, DateError>
+    where
+        Tz::Offset: Copy,
+    {
+        let d = parse_date_string(s, now, Dialect::Us)?;
+        let ts = Timestamp::from_datetime(d.to_utc().fixed_offset());
+        Ok(TimeExpression::AtOrAfter(ts))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use chrono::DateTime;
+
+    use super::*;
+
+    fn test_equal<Tz: TimeZone>(now: DateTime<Tz>, expression: &str, should_equal_time: &str)
+    where
+        Tz::Offset: Copy,
+    {
+        let expression = TimeExpression::parse(expression, now).unwrap();
+        assert_eq!(
+            expression,
+            TimeExpression::AtOrAfter(Timestamp::from_datetime(
+                DateTime::parse_from_rfc3339(should_equal_time)
+                    .unwrap()
+                    .to_utc()
+                    .fixed_offset()
+            ))
+        );
+    }
+
+    #[test]
+    fn test_time_expression_parses_dates_without_times_as_the_date_at_local_midnight() {
+        let now = DateTime::parse_from_rfc3339("2024-01-01T00:00:00-08:00").unwrap();
+        test_equal(now, "2023-03-25", "2023-03-25T08:00:00Z");
+        test_equal(now, "3/25/2023", "2023-03-25T08:00:00Z");
+        test_equal(now, "3/25/23", "2023-03-25T08:00:00Z");
+    }
+
+    #[test]
+    fn test_time_expression_parses_dates_with_times_without_specifying_an_offset() {
+        let now = DateTime::parse_from_rfc3339("2024-01-01T00:00:00-08:00").unwrap();
+        test_equal(now, "2023-03-25T00:00:00", "2023-03-25T08:00:00Z");
+        test_equal(now, "2023-03-25 00:00:00", "2023-03-25T08:00:00Z");
+    }
+
+    #[test]
+    fn test_time_expression_parses_dates_with_a_specified_offset() {
+        let now = DateTime::parse_from_rfc3339("2024-01-01T00:00:00-08:00").unwrap();
+        test_equal(
+            now,
+            "2023-03-25T00:00:00-05:00",
+            "2023-03-25T00:00:00-05:00",
+        );
+    }
+
+    #[test]
+    fn test_time_expression_parses_dates_with_the_z_offset() {
+        let now = DateTime::parse_from_rfc3339("2024-01-01T00:00:00-08:00").unwrap();
+        test_equal(now, "2023-03-25T00:00:00Z", "2023-03-25T00:00:00Z");
+    }
+
+    #[test]
+    fn test_time_expression_parses_relative_durations() {
+        let now = DateTime::parse_from_rfc3339("2024-01-01T00:00:00-08:00").unwrap();
+        test_equal(now, "2 hours ago", "2024-01-01T06:00:00Z");
+        test_equal(now, "5 minutes", "2024-01-01T08:05:00Z");
+        test_equal(now, "1 week ago", "2023-12-25T08:00:00Z");
+        test_equal(now, "yesterday", "2023-12-31T08:00:00Z");
+        test_equal(now, "tomorrow", "2024-01-02T08:00:00Z");
+    }
+
+    #[test]
+    fn test_time_expression_parses_relative_dates_with_times() {
+        let now = DateTime::parse_from_rfc3339("2024-01-01T08:00:00-08:00").unwrap();
+        test_equal(now, "yesterday 5pm", "2024-01-01T01:00:00Z");
+        test_equal(now, "yesterday 10am", "2023-12-31T18:00:00Z");
+        test_equal(now, "yesterday 10:30", "2023-12-31T18:30:00Z");
+    }
+}