chore(rust!): move offset_by implementation from polars-plan to polar…

…s-time, rename feature from DateOffset to OffsetBy

crates/polars-lazy/Cargo.toml

@@ -98,7 +98,7 @@ dtype-u16 = ["polars-plan/dtype-u16", "polars-pipe?/dtype-u16", "polars-expr/dty
 dtype-u8 = ["polars-plan/dtype-u8", "polars-pipe?/dtype-u8", "polars-expr/dtype-u8"]
 
 object = ["polars-plan/object"]
-date_offset = ["polars-plan/date_offset"]
+offset_by = ["polars-plan/offset_by"]
 trigonometry = ["polars-plan/trigonometry"]
 sign = ["polars-plan/sign"]
 timezones = ["polars-plan/timezones"]
@@ -258,7 +258,7 @@ features = [
   "cum_agg",
   "cumulative_eval",
   "cutqcut",
-  "date_offset",
+  "offset_by",
   "diagonal_concat",
   "diff",
   "dot_diagram",

crates/polars-plan/Cargo.toml

@@ -88,7 +88,7 @@ dtype-array = ["polars-core/dtype-array", "polars-ops/dtype-array"]
 dtype-categorical = ["polars-core/dtype-categorical"]
 dtype-struct = ["polars-core/dtype-struct"]
 object = ["polars-core/object"]
-date_offset = ["polars-time", "chrono"]
+offset_by = ["polars-time", "chrono"]
 list_gather = ["polars-ops/list_gather"]
 list_count = ["polars-ops/list_count"]
 array_count = ["polars-ops/array_count", "dtype-array"]
@@ -199,7 +199,7 @@ features = [
   "is_last_distinct",
   "dtype-time",
   "array_any_all",
-  "date_offset",
+  "offset_by",
   "parquet",
   "strings",
   "row_hash",

crates/polars-plan/src/dsl/dt.rs

@@ -213,14 +213,14 @@ impl DateLikeNameSpace {
     }
 
     /// Roll backward to the first day of the month.
-    #[cfg(feature = "date_offset")]
+    #[cfg(feature = "offset_by")]
     pub fn month_start(self) -> Expr {
         self.0
             .map_private(FunctionExpr::TemporalExpr(TemporalFunction::MonthStart))
     }
 
     /// Roll forward to the last day of the month.
-    #[cfg(feature = "date_offset")]
+    #[cfg(feature = "offset_by")]
     pub fn month_end(self) -> Expr {
         self.0
             .map_private(FunctionExpr::TemporalExpr(TemporalFunction::MonthEnd))
@@ -252,10 +252,14 @@ impl DateLikeNameSpace {
 
     /// Offset this `Date/Datetime` by a given offset [`Duration`].
     /// This will take leap years/ months into account.
-    #[cfg(feature = "date_offset")]
+    #[cfg(feature = "offset_by")]
     pub fn offset_by(self, by: Expr) -> Expr {
-        self.0
-            .map_many_private(FunctionExpr::DateOffset, &[by], false, false)
+        self.0.map_many_private(
+            FunctionExpr::TemporalExpr(TemporalFunction::OffsetBy),
+            &[by],
+            false,
+            false,
+        )
     }
 
     #[cfg(feature = "timezones")]

crates/polars-plan/src/dsl/function_expr/datetime.rs

@@ -5,6 +5,8 @@ use chrono_tz::Tz;
 use polars_time::base_utc_offset as base_utc_offset_fn;
 #[cfg(feature = "timezones")]
 use polars_time::dst_offset as dst_offset_fn;
+#[cfg(feature = "offset_by")]
+use polars_time::impl_offset_by;
 #[cfg(feature = "serde")]
 use serde::{Deserialize, Serialize};
 
@@ -48,9 +50,11 @@ pub enum TemporalFunction {
     ConvertTimeZone(TimeZone),
     TimeStamp(TimeUnit),
     Truncate,
-    #[cfg(feature = "date_offset")]
+    #[cfg(feature = "offset_by")]
+    OffsetBy,
+    #[cfg(feature = "offset_by")]
     MonthStart,
-    #[cfg(feature = "date_offset")]
+    #[cfg(feature = "offset_by")]
     MonthEnd,
     #[cfg(feature = "timezones")]
     BaseUtcOffset,
@@ -101,9 +105,11 @@ impl TemporalFunction {
                 dtype => polars_bail!(ComputeError: "expected Datetime, got {}", dtype),
             }),
             Truncate => mapper.with_same_dtype(),
-            #[cfg(feature = "date_offset")]
+            #[cfg(feature = "offset_by")]
+            OffsetBy => mapper.with_same_dtype(),
+            #[cfg(feature = "offset_by")]
             MonthStart => mapper.with_same_dtype(),
-            #[cfg(feature = "date_offset")]
+            #[cfg(feature = "offset_by")]
             MonthEnd => mapper.with_same_dtype(),
             #[cfg(feature = "timezones")]
             BaseUtcOffset => mapper.with_dtype(DataType::Duration(TimeUnit::Milliseconds)),
@@ -169,9 +175,11 @@ impl Display for TemporalFunction {
             WithTimeUnit(_) => "with_time_unit",
             TimeStamp(tu) => return write!(f, "dt.timestamp({tu})"),
             Truncate => "truncate",
-            #[cfg(feature = "date_offset")]
+            #[cfg(feature = "offset_by")]
+            OffsetBy => "offset_by",
+            #[cfg(feature = "offset_by")]
             MonthStart => "month_start",
-            #[cfg(feature = "date_offset")]
+            #[cfg(feature = "offset_by")]
             MonthEnd => "month_end",
             #[cfg(feature = "timezones")]
             BaseUtcOffset => "base_utc_offset",
@@ -392,7 +400,12 @@ pub(super) fn truncate(s: &[Series]) -> PolarsResult<Series> {
     Ok(out)
 }
 
-#[cfg(feature = "date_offset")]
+#[cfg(feature = "offset_by")]
+pub(super) fn offset_by(s: &[Series]) -> PolarsResult<Series> {
+    impl_offset_by(&s[0], &s[1])
+}
+
+#[cfg(feature = "offset_by")]
 pub(super) fn month_start(s: &Series) -> PolarsResult<Series> {
     Ok(match s.dtype() {
         DataType::Datetime(_, tz) => match tz {
@@ -409,7 +422,7 @@ pub(super) fn month_start(s: &Series) -> PolarsResult<Series> {
     })
 }
 
-#[cfg(feature = "date_offset")]
+#[cfg(feature = "offset_by")]
 pub(super) fn month_end(s: &Series) -> PolarsResult<Series> {
     Ok(match s.dtype() {
         DataType::Datetime(_, tz) => match tz {

crates/polars-plan/src/dsl/function_expr/mod.rs

@@ -62,7 +62,7 @@ mod sign;
 mod strings;
 #[cfg(feature = "dtype-struct")]
 mod struct_;
-#[cfg(any(feature = "temporal", feature = "date_offset"))]
+#[cfg(any(feature = "temporal", feature = "offset_by"))]
 mod temporal;
 #[cfg(feature = "trigonometry")]
 pub mod trigonometry;
@@ -148,8 +148,6 @@ pub enum FunctionExpr {
     SearchSorted(SearchSortedSide),
     #[cfg(feature = "range")]
     Range(RangeFunction),
-    #[cfg(feature = "date_offset")]
-    DateOffset,
     #[cfg(feature = "trigonometry")]
     Trigonometry(TrigonometricFunction),
     #[cfg(feature = "trigonometry")]
@@ -413,8 +411,6 @@ impl Hash for FunctionExpr {
             Abs => {},
             Negate => {},
             NullCount => {},
-            #[cfg(feature = "date_offset")]
-            DateOffset => {},
             #[cfg(feature = "arg_where")]
             ArgWhere => {},
             #[cfg(feature = "trigonometry")]
@@ -615,8 +611,6 @@ impl Display for FunctionExpr {
             SearchSorted(_) => "search_sorted",
             #[cfg(feature = "range")]
             Range(func) => return write!(f, "{func}"),
-            #[cfg(feature = "date_offset")]
-            DateOffset => "dt.offset_by",
             #[cfg(feature = "trigonometry")]
             Trigonometry(func) => return write!(f, "{func}"),
             #[cfg(feature = "trigonometry")]
@@ -900,11 +894,6 @@ impl From<FunctionExpr> for SpecialEq<Arc<dyn SeriesUdf>> {
             #[cfg(feature = "range")]
             Range(func) => func.into(),
 
-            #[cfg(feature = "date_offset")]
-            DateOffset => {
-                map_as_slice!(temporal::date_offset)
-            },
-
             #[cfg(feature = "trigonometry")]
             Trigonometry(trig_function) => {
                 map!(trigonometry::apply_trigonometric_function, trig_function)

crates/polars-plan/src/dsl/function_expr/schema.rs

@@ -51,8 +51,6 @@ impl FunctionExpr {
             SearchSorted(_) => mapper.with_dtype(IDX_DTYPE),
             #[cfg(feature = "range")]
             Range(func) => func.get_field(mapper),
-            #[cfg(feature = "date_offset")]
-            DateOffset { .. } => mapper.with_same_dtype(),
             #[cfg(feature = "trigonometry")]
             Trigonometry(_) => mapper.map_to_float_dtype(),
             #[cfg(feature = "trigonometry")]

crates/polars-plan/src/dsl/function_expr/temporal.rs

@@ -1,10 +1,3 @@
-#[cfg(feature = "date_offset")]
-use arrow::legacy::time_zone::Tz;
-#[cfg(feature = "date_offset")]
-use polars_core::chunked_array::ops::arity::broadcast_try_binary_elementwise;
-#[cfg(feature = "date_offset")]
-use polars_time::prelude::*;
-
 use super::*;
 use crate::{map, map_as_slice};
 
@@ -49,9 +42,13 @@ impl From<TemporalFunction> for SpecialEq<Arc<dyn SeriesUdf>> {
             Truncate => {
                 map_as_slice!(datetime::truncate)
             },
-            #[cfg(feature = "date_offset")]
+            #[cfg(feature = "offset_by")]
+            OffsetBy => {
+                map_as_slice!(datetime::offset_by)
+            },
+            #[cfg(feature = "offset_by")]
             MonthStart => map!(datetime::month_start),
-            #[cfg(feature = "date_offset")]
+            #[cfg(feature = "offset_by")]
             MonthEnd => map!(datetime::month_end),
             #[cfg(feature = "timezones")]
             BaseUtcOffset => map!(datetime::base_utc_offset),
@@ -185,125 +182,6 @@ pub(super) fn datetime(
     Ok(s)
 }
 
-#[cfg(feature = "date_offset")]
-fn apply_offsets_to_datetime(
-    datetime: &Logical<DatetimeType, Int64Type>,
-    offsets: &StringChunked,
-    time_zone: Option<&Tz>,
-) -> PolarsResult<Int64Chunked> {
-    match offsets.len() {
-        1 => match offsets.get(0) {
-            Some(offset) => {
-                let offset = &Duration::parse(offset);
-                if offset.is_constant_duration(datetime.time_zone().as_deref()) {
-                    // fastpath!
-                    let mut duration = match datetime.time_unit() {
-                        TimeUnit::Milliseconds => offset.duration_ms(),
-                        TimeUnit::Microseconds => offset.duration_us(),
-                        TimeUnit::Nanoseconds => offset.duration_ns(),
-                    };
-                    if offset.negative() {
-                        duration = -duration;
-                    }
-                    Ok(datetime.0.clone().wrapping_add_scalar(duration))
-                } else {
-                    let offset_fn = match datetime.time_unit() {
-                        TimeUnit::Milliseconds => Duration::add_ms,
-                        TimeUnit::Microseconds => Duration::add_us,
-                        TimeUnit::Nanoseconds => Duration::add_ns,
-                    };
-                    datetime
-                        .0
-                        .try_apply_nonnull_values_generic(|v| offset_fn(offset, v, time_zone))
-                }
-            },
-            _ => Ok(datetime.0.apply(|_| None)),
-        },
-        _ => {
-            let offset_fn = match datetime.time_unit() {
-                TimeUnit::Milliseconds => Duration::add_ms,
-                TimeUnit::Microseconds => Duration::add_us,
-                TimeUnit::Nanoseconds => Duration::add_ns,
-            };
-            broadcast_try_binary_elementwise(datetime, offsets, |timestamp_opt, offset_opt| match (
-                timestamp_opt,
-                offset_opt,
-            ) {
-                (Some(timestamp), Some(offset)) => {
-                    offset_fn(&Duration::parse(offset), timestamp, time_zone).map(Some)
-                },
-                _ => Ok(None),
-            })
-        },
-    }
-}
-
-#[cfg(feature = "date_offset")]
-pub(super) fn date_offset(s: &[Series]) -> PolarsResult<Series> {
-    let ts = &s[0];
-    let offsets = &s[1].str()?;
-
-    let preserve_sortedness: bool;
-    let out = match ts.dtype() {
-        DataType::Date => {
-            let ts = ts
-                .cast(&DataType::Datetime(TimeUnit::Milliseconds, None))
-                .unwrap();
-            let datetime = ts.datetime().unwrap();
-            let out = apply_offsets_to_datetime(datetime, offsets, None)?;
-            // sortedness is only guaranteed to be preserved if a constant offset is being added to every datetime
-            preserve_sortedness = match offsets.len() {
-                1 => offsets.get(0).is_some(),
-                _ => false,
-            };
-            out.cast(&DataType::Datetime(TimeUnit::Milliseconds, None))
-                .unwrap()
-                .cast(&DataType::Date)
-        },
-        DataType::Datetime(tu, tz) => {
-            let datetime = ts.datetime().unwrap();
-
-            let out = match tz {
-                #[cfg(feature = "timezones")]
-                Some(ref tz) => {
-                    apply_offsets_to_datetime(datetime, offsets, tz.parse::<Tz>().ok().as_ref())?
-                },
-                _ => apply_offsets_to_datetime(datetime, offsets, None)?,
-            };
-            // Sortedness may not be preserved when crossing daylight savings time boundaries
-            // for calendar-aware durations.
-            // Constant durations (e.g. 2 hours) always preserve sortedness.
-            preserve_sortedness = match offsets.len() {
-                1 => match offsets.get(0) {
-                    Some(offset) => {
-                        let offset = Duration::parse(offset);
-                        tz.is_none()
-                            || tz.as_deref() == Some("UTC")
-                            || offset.is_constant_duration(tz.as_deref())
-                    },
-                    None => false,
-                },
-                _ => false,
-            };
-            out.cast(&DataType::Datetime(*tu, tz.clone()))
-        },
-        dt => polars_bail!(
-            ComputeError: "cannot use 'date_offset' on Series of datatype {}", dt,
-        ),
-    };
-    if preserve_sortedness {
-        out.map(|mut out| {
-            out.set_sorted_flag(ts.is_sorted_flag());
-            out
-        })
-    } else {
-        out.map(|mut out| {
-            out.set_sorted_flag(IsSorted::Not);
-            out
-        })
-    }
-}
-
 pub(super) fn combine(s: &[Series], tu: TimeUnit) -> PolarsResult<Series> {
     let date = &s[0];
     let time = &s[1];

crates/polars-time/src/lib.rs

@@ -6,6 +6,7 @@ mod dst_offset;
 mod group_by;
 mod month_end;
 mod month_start;
+mod offset_by;
 pub mod prelude;
 mod round;
 pub mod series;
@@ -23,6 +24,7 @@ pub use dst_offset::*;
 pub use group_by::dynamic::*;
 pub use month_end::*;
 pub use month_start::*;
+pub use offset_by::*;
 pub use round::*;
 pub use truncate::*;
 pub use upsample::*;