revset: add author_date and committer_date revset functions

These functions always filter for dates at or after the specified date. To
invert the filter, combine it with the ~ operator:

    # anything authored before yesterday at midnight
    ~author_date("yesterday")

cli/src/cli_util.rs

@@ -994,6 +994,7 @@ impl WorkspaceCommandHelper {
         RevsetParseContext::new(
             &self.revset_aliases_map,
             self.settings.user_email(),
+            chrono::Local::now(),
             &self.revset_extensions,
             Some(workspace_context),
         )

cli/tests/test_revset_output.rs

@@ -290,7 +290,7 @@ fn test_function_name_hint() {
       | ^-----^
       |
       = Function "author_" doesn't exist
-    Hint: Did you mean "author", "my_author"?
+    Hint: Did you mean "author", "author_date", "my_author"?
     "###);
 
     insta::assert_snapshot!(evaluate_err("my_branches"), @r###"

docs/revsets.md

@@ -257,6 +257,10 @@ revsets (expressions) as arguments.
 * `committer(pattern)`: Commits with the committer's  name or email matching the
 given [string pattern](#string-patterns).
 
+* `author_date(pattern)`: Commits authored within at or after specified [date](#date-patterns).
+
+* `committer_date(pattern)`: Commits committed at or after the specified [date](#date-patterns).
+
 * `empty()`: Commits modifying no files. This also includes `merges()` without
   user modifications and `root()`.
 
@@ -333,6 +337,21 @@ Functions that perform string matching support the following pattern syntax:
 * `glob:"pattern"`: Matches strings with Unix-style shell [wildcard
   `pattern`](https://docs.rs/glob/latest/glob/struct.Pattern.html).
 
+## Date patterns
+
+Date patterns can be specified in several forms, including:
+
+* 2024-02-01
+* 2024-02-01T12:00:00
+* 2024-02-01T12:00:00-08:00
+* 2024-02-01 12:00:00
+* 2 days ago
+* 5 minutes ago
+* yesterday
+* yesterday 5pm
+* yesterday 10:30
+* yesterday 15:30
+
 ## Aliases
 
 New symbols and functions can be defined in the config file, by using any

lib/src/default_index/revset_engine.rs

@@ -36,6 +36,7 @@ use crate::revset::{
     RevsetFilterPredicate, GENERATION_RANGE_FULL,
 };
 use crate::store::Store;
+use crate::time_expression::TimeExpression;
 use crate::{rewrite, union_find};
 
 type BoxedPredicateFn<'a> = Box<dyn FnMut(&CompositeIndex, IndexPosition) -> bool + 'a>;
@@ -1069,6 +1070,28 @@ fn build_predicate_fn(
                     || pattern.matches(&commit.committer().email)
             })
         }
+        RevsetFilterPredicate::AuthorDate(expression) => {
+            let expression = expression.clone();
+            box_pure_predicate_fn(move |index, pos| {
+                let entry = index.entry_by_pos(pos);
+                let commit = store.get_commit(&entry.commit_id()).unwrap();
+                let author_date = &commit.author().timestamp;
+                match &expression {
+                    TimeExpression::AtOrAfter(ts) => ts.le(author_date),
+                }
+            })
+        }
+        RevsetFilterPredicate::CommitterDate(expression) => {
+            let expression = expression.clone();
+            box_pure_predicate_fn(move |index, pos| {
+                let entry = index.entry_by_pos(pos);
+                let commit = store.get_commit(&entry.commit_id()).unwrap();
+                let committer_date = &commit.committer().timestamp;
+                match &expression {
+                    TimeExpression::AtOrAfter(ts) => ts.le(committer_date),
+                }
+            })
+        }
         RevsetFilterPredicate::File(expr) => {
             let matcher: Rc<dyn Matcher> = expr.to_matcher().into();
             box_pure_predicate_fn(move |index, pos| {

lib/src/revset.rs

@@ -22,6 +22,7 @@ use std::ops::Range;
 use std::rc::Rc;
 use std::sync::Arc;
 
+use chrono::{DateTime, FixedOffset, NaiveDateTime, Offset, TimeZone};
 use itertools::Itertools;
 use once_cell::sync::Lazy;
 use thiserror::Error;
@@ -43,6 +44,7 @@ pub use crate::revset_parser::{
 };
 use crate::store::Store;
 use crate::str_util::StringPattern;
+use crate::time_expression::TimeExpression;
 use crate::{dsl_util, revset_parser};
 
 /// Error occurred during symbol resolution.
@@ -131,6 +133,10 @@ pub enum RevsetFilterPredicate {
     Author(StringPattern),
     /// Commits with committer's name or email containing the needle.
     Committer(StringPattern),
+    /// Commits authored after the given date.
+    AuthorDate(TimeExpression),
+    /// Commits committed after the given date.
+    CommitterDate(TimeExpression),
     /// Commits modifying the paths specified by the fileset.
     File(FilesetExpression),
     /// Commits with conflicts
@@ -685,6 +691,13 @@ static BUILTIN_FUNCTION_MAP: Lazy<HashMap<&'static str, RevsetFunction>> = Lazy:
             pattern,
         )))
     });
+    map.insert("author_date", |function, context| {
+        let [arg] = function.expect_exact_arguments()?;
+        let pattern = expect_time_expression(arg, context.now().to_owned())?;
+        Ok(RevsetExpression::filter(RevsetFilterPredicate::AuthorDate(
+            pattern,
+        )))
+    });
     map.insert("mine", |function, context| {
         function.expect_no_arguments()?;
         Ok(RevsetExpression::filter(RevsetFilterPredicate::Author(
@@ -698,6 +711,13 @@ static BUILTIN_FUNCTION_MAP: Lazy<HashMap<&'static str, RevsetFunction>> = Lazy:
             pattern,
         )))
     });
+    map.insert("committer_date", |function, context| {
+        let [arg] = function.expect_exact_arguments()?;
+        let pattern = expect_time_expression(arg, context.now().to_owned())?;
+        Ok(RevsetExpression::filter(
+            RevsetFilterPredicate::CommitterDate(pattern),
+        ))
+    });
     map.insert("empty", |function, _context| {
         function.expect_no_arguments()?;
         Ok(RevsetExpression::is_empty())
@@ -749,6 +769,20 @@ pub fn expect_string_pattern(node: &ExpressionNode) -> Result<StringPattern, Rev
     revset_parser::expect_pattern_with("string pattern", node, parse_pattern)
 }
 
+fn expect_time_expression<Tz: TimeZone>(
+    node: &ExpressionNode,
+    now: DateTime<Tz>,
+) -> Result<TimeExpression, RevsetParseError>
+where
+    Tz::Offset: Copy,
+{
+    let expression = revset_parser::expect_literal::<String>("time expression", node)?;
+    TimeExpression::parse(&expression, now).map_err(|err| {
+        RevsetParseError::expression(format!("Unable to parse time expression: {err}"), node.span)
+            .with_source(err)
+    })
+}
+
 /// Resolves function call by using the given function map.
 fn lower_function_call(
     function: &FunctionCallNode,
@@ -1977,20 +2011,29 @@ impl RevsetExtensions {
 pub struct RevsetParseContext<'a> {
     aliases_map: &'a RevsetAliasesMap,
     user_email: String,
+    /// The current local time when the revset expression was written.
+    now: NaiveDateTime,
+    /// The offset from UTC at the time the revset expression was written. TODO:
+    /// It would be better if this was the TimeZone so times could be computed
+    /// correctly across DST shifts.
+    offset: FixedOffset,
     extensions: &'a RevsetExtensions,
     workspace: Option<RevsetWorkspaceContext<'a>>,
 }
 
 impl<'a> RevsetParseContext<'a> {
-    pub fn new(
+    pub fn new<Tz: TimeZone>(
         aliases_map: &'a RevsetAliasesMap,
         user_email: String,
+        now: DateTime<Tz>,
         extensions: &'a RevsetExtensions,
         workspace: Option<RevsetWorkspaceContext<'a>>,
     ) -> Self {
         Self {
             aliases_map,
             user_email,
+            now: now.naive_local(),
+            offset: now.offset().fix(),
             extensions,
             workspace,
         }
@@ -2004,6 +2047,10 @@ impl<'a> RevsetParseContext<'a> {
         &self.user_email
     }
 
+    pub fn now(&self) -> DateTime<FixedOffset> {
+        DateTime::from_naive_utc_and_offset(self.now, self.offset)
+    }
+
     pub fn symbol_resolvers(&self) -> &[impl AsRef<dyn SymbolResolverExtension>] {
         self.extensions.symbol_resolvers()
     }
@@ -2047,6 +2094,7 @@ mod tests {
         let context = RevsetParseContext::new(
             &aliases_map,
             "[email protected]".to_string(),
+            chrono::Utc::now(),
             &extensions,
             None,
         );
@@ -2076,6 +2124,7 @@ mod tests {
         let context = RevsetParseContext::new(
             &aliases_map,
             "[email protected]".to_string(),
+            chrono::Utc::now(),
             &extensions,
             Some(workspace_ctx),
         );
@@ -2101,6 +2150,7 @@ mod tests {
         let context = RevsetParseContext::new(
             &aliases_map,
             "[email protected]".to_string(),
+            chrono::Utc::now(),
             &extensions,
             None,
         );