From 736c5676711f4aa154832cd56895ab15ae063c7f Mon Sep 17 00:00:00 2001
From: "Shane F. Carr" <shane@unicode.org>
Date: Fri, 20 Dec 2024 13:35:34 -0800
Subject: [PATCH] Refactor NamesContainer

---
 components/datetime/src/pattern/names.rs      | 115 +++++++++++-------
 components/datetime/src/scaffold/mod.rs       |   2 +-
 .../datetime/src/scaffold/names_storage.rs    |  49 ++++----
 3 files changed, 99 insertions(+), 67 deletions(-)

diff --git a/components/datetime/src/pattern/names.rs b/components/datetime/src/pattern/names.rs
index d6a97b83ad8..8159f0c2d2f 100644
--- a/components/datetime/src/pattern/names.rs
+++ b/components/datetime/src/pattern/names.rs
@@ -228,41 +228,30 @@ pub struct TypedDateTimeNames<
 }
 
 pub(crate) struct RawDateTimeNames<FSet: DateTimeNamesMarker> {
-    year_names:
-        <FSet::YearNames as DateTimeNamesHolderTrait<YearNamesV1Marker>>::Container<FieldLength>,
-    month_names: <FSet::MonthNames as DateTimeNamesHolderTrait<MonthNamesV1Marker>>::Container<(
-        fields::Month,
-        FieldLength,
-    )>,
-    weekday_names:
-        <FSet::WeekdayNames as DateTimeNamesHolderTrait<WeekdayNamesV1Marker>>::Container<(
-            fields::Weekday,
-            FieldLength,
-        )>,
+    year_names: <FSet::YearNames as NamesContainer<YearNamesV1Marker, FieldLength>>::Container,
+    month_names: <FSet::MonthNames as NamesContainer<
+        MonthNamesV1Marker,
+        (fields::Month, FieldLength),
+    >>::Container,
+    weekday_names: <FSet::WeekdayNames as NamesContainer<
+        WeekdayNamesV1Marker,
+        (fields::Weekday, FieldLength),
+    >>::Container,
     dayperiod_names:
-        <FSet::DayPeriodNames as DateTimeNamesHolderTrait<DayPeriodNamesV1Marker>>::Container<
-            FieldLength,
-        >,
+        <FSet::DayPeriodNames as NamesContainer<DayPeriodNamesV1Marker, FieldLength>>::Container,
     zone_essentials:
-        <FSet::ZoneEssentials as DateTimeNamesHolderTrait<tz::EssentialsV1Marker>>::Container<()>,
-    locations_root:
-        <FSet::ZoneLocations as DateTimeNamesHolderTrait<tz::LocationsV1Marker>>::Container<()>,
-    locations:
-        <FSet::ZoneLocations as DateTimeNamesHolderTrait<tz::LocationsV1Marker>>::Container<()>,
-    mz_generic_long: <FSet::ZoneGenericLong as DateTimeNamesHolderTrait<
-        tz::MzGenericLongV1Marker,
-    >>::Container<()>,
-    mz_generic_short: <FSet::ZoneGenericShort as DateTimeNamesHolderTrait<
-        tz::MzGenericShortV1Marker,
-    >>::Container<()>,
-    mz_specific_long: <FSet::ZoneSpecificLong as DateTimeNamesHolderTrait<
-        tz::MzSpecificLongV1Marker,
-    >>::Container<()>,
-    mz_specific_short: <FSet::ZoneSpecificShort as DateTimeNamesHolderTrait<
-        tz::MzSpecificShortV1Marker,
-    >>::Container<()>,
-    mz_periods:
-        <FSet::MetazoneLookup as DateTimeNamesHolderTrait<tz::MzPeriodV1Marker>>::Container<()>,
+        <FSet::ZoneEssentials as NamesContainer<tz::EssentialsV1Marker, ()>>::Container,
+    locations_root: <FSet::ZoneLocations as NamesContainer<tz::LocationsV1Marker, ()>>::Container,
+    locations: <FSet::ZoneLocations as NamesContainer<tz::LocationsV1Marker, ()>>::Container,
+    mz_generic_long:
+        <FSet::ZoneGenericLong as NamesContainer<tz::MzGenericLongV1Marker, ()>>::Container,
+    mz_generic_short:
+        <FSet::ZoneGenericShort as NamesContainer<tz::MzGenericShortV1Marker, ()>>::Container,
+    mz_specific_long:
+        <FSet::ZoneSpecificLong as NamesContainer<tz::MzSpecificLongV1Marker, ()>>::Container,
+    mz_specific_short:
+        <FSet::ZoneSpecificShort as NamesContainer<tz::MzSpecificShortV1Marker, ()>>::Container,
+    mz_periods: <FSet::MetazoneLookup as NamesContainer<tz::MzPeriodV1Marker, ()>>::Container,
     // TODO(#4340): Make the FixedDecimalFormatter optional
     fixed_decimal_formatter: Option<FixedDecimalFormatter>,
     _marker: PhantomData<FSet>,
@@ -1315,18 +1304,54 @@ impl<C: CldrCalendar, FSet: DateTimeNamesMarker> TypedDateTimeNames<C, FSet> {
 impl<FSet: DateTimeNamesMarker> RawDateTimeNames<FSet> {
     pub(crate) fn new_without_number_formatting() -> Self {
         Self {
-            year_names: <FSet::YearNames as DateTimeNamesHolderTrait<YearNamesV1Marker>>::Container::<_>::new_empty(),
-            month_names: <FSet::MonthNames as DateTimeNamesHolderTrait<MonthNamesV1Marker>>::Container::<_>::new_empty(),
-            weekday_names: <FSet::WeekdayNames as DateTimeNamesHolderTrait<WeekdayNamesV1Marker>>::Container::<_>::new_empty(),
-            dayperiod_names: <FSet::DayPeriodNames as DateTimeNamesHolderTrait<DayPeriodNamesV1Marker>>::Container::<_>::new_empty(),
-            zone_essentials: <FSet::ZoneEssentials as DateTimeNamesHolderTrait<tz::EssentialsV1Marker>>::Container::<_>::new_empty(),
-            locations_root: <FSet::ZoneLocations as DateTimeNamesHolderTrait<tz::LocationsV1Marker>>::Container::<_>::new_empty(),
-            locations: <FSet::ZoneLocations as DateTimeNamesHolderTrait<tz::LocationsV1Marker>>::Container::<_>::new_empty(),
-            mz_generic_long: <FSet::ZoneGenericLong as DateTimeNamesHolderTrait<tz::MzGenericLongV1Marker>>::Container::<_>::new_empty(),
-            mz_generic_short: <FSet::ZoneGenericShort as DateTimeNamesHolderTrait<tz::MzGenericShortV1Marker>>::Container::<_>::new_empty(),
-            mz_specific_long: <FSet::ZoneSpecificLong as DateTimeNamesHolderTrait<tz::MzSpecificLongV1Marker>>::Container::<_>::new_empty(),
-            mz_specific_short: <FSet::ZoneSpecificShort as DateTimeNamesHolderTrait<tz::MzSpecificShortV1Marker>>::Container::<_>::new_empty(),
-            mz_periods: <FSet::MetazoneLookup as DateTimeNamesHolderTrait<tz::MzPeriodV1Marker>>::Container::<_>::new_empty(),
+            year_names: <FSet::YearNames as NamesContainer<
+                YearNamesV1Marker,
+                FieldLength,
+            >>::Container::new_empty(),
+            month_names: <FSet::MonthNames as NamesContainer<
+                MonthNamesV1Marker,
+                (fields::Month, FieldLength),
+            >>::Container::new_empty(),
+            weekday_names: <FSet::WeekdayNames as NamesContainer<
+                WeekdayNamesV1Marker,
+                (fields::Weekday, FieldLength),
+            >>::Container::new_empty(),
+            dayperiod_names: <FSet::DayPeriodNames as NamesContainer<
+                DayPeriodNamesV1Marker,
+                FieldLength,
+            >>::Container::new_empty(),
+            zone_essentials: <FSet::ZoneEssentials as NamesContainer<
+                tz::EssentialsV1Marker,
+                (),
+            >>::Container::new_empty(),
+            locations_root: <FSet::ZoneLocations as NamesContainer<
+                tz::LocationsV1Marker,
+                (),
+            >>::Container::new_empty(),
+            locations: <FSet::ZoneLocations as NamesContainer<
+                tz::LocationsV1Marker,
+                (),
+            >>::Container::new_empty(),
+            mz_generic_long: <FSet::ZoneGenericLong as NamesContainer<
+                tz::MzGenericLongV1Marker,
+                (),
+            >>::Container::new_empty(),
+            mz_generic_short: <FSet::ZoneGenericShort as NamesContainer<
+                tz::MzGenericShortV1Marker,
+                (),
+            >>::Container::new_empty(),
+            mz_specific_long: <FSet::ZoneSpecificLong as NamesContainer<
+                tz::MzSpecificLongV1Marker,
+                (),
+            >>::Container::new_empty(),
+            mz_specific_short: <FSet::ZoneSpecificShort as NamesContainer<
+                tz::MzSpecificShortV1Marker,
+                (),
+            >>::Container::new_empty(),
+            mz_periods: <FSet::MetazoneLookup as NamesContainer<
+                tz::MzPeriodV1Marker,
+                (),
+            >>::Container::new_empty(),
             fixed_decimal_formatter: None,
             _marker: PhantomData,
         }
diff --git a/components/datetime/src/scaffold/mod.rs b/components/datetime/src/scaffold/mod.rs
index 96e93eec41c..7497242d2a0 100644
--- a/components/datetime/src/scaffold/mod.rs
+++ b/components/datetime/src/scaffold/mod.rs
@@ -39,10 +39,10 @@ pub use get_field::GetField;
 
 pub use names_storage::DataPayloadWithVariables;
 pub use names_storage::DataPayloadWithVariablesBorrowed;
-pub use names_storage::DateTimeNamesHolderTrait;
 pub use names_storage::DateTimeNamesMarker;
 pub use names_storage::MaybePayload;
 pub use names_storage::MaybePayloadError;
+pub use names_storage::NamesContainer;
 pub(crate) use names_storage::OptionalNames;
 
 /// Trait marking other traits that are considered unstable and should not generally be
diff --git a/components/datetime/src/scaffold/names_storage.rs b/components/datetime/src/scaffold/names_storage.rs
index fd6bcc8e345..46dea7201f1 100644
--- a/components/datetime/src/scaffold/names_storage.rs
+++ b/components/datetime/src/scaffold/names_storage.rs
@@ -2,7 +2,7 @@
 // called LICENSE at the top level of the ICU4X source tree
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
-use crate::fields::Field;
+use crate::fields::{self, Field, FieldLength};
 use crate::pattern::PatternLoadError;
 use crate::provider::neo::*;
 use crate::provider::time_zones::tz;
@@ -19,36 +19,43 @@ use super::UnstableSealed;
 /// not weekday, day period, or time zone names.
 #[allow(missing_docs)]
 pub trait DateTimeNamesMarker: UnstableSealed {
-    type YearNames: DateTimeNamesHolderTrait<YearNamesV1Marker>;
-    type MonthNames: DateTimeNamesHolderTrait<MonthNamesV1Marker>;
-    type WeekdayNames: DateTimeNamesHolderTrait<WeekdayNamesV1Marker>;
-    type DayPeriodNames: DateTimeNamesHolderTrait<DayPeriodNamesV1Marker>;
-    type ZoneEssentials: DateTimeNamesHolderTrait<tz::EssentialsV1Marker>;
-    type ZoneLocations: DateTimeNamesHolderTrait<tz::LocationsV1Marker>;
-    type ZoneGenericLong: DateTimeNamesHolderTrait<tz::MzGenericLongV1Marker>;
-    type ZoneGenericShort: DateTimeNamesHolderTrait<tz::MzGenericShortV1Marker>;
-    type ZoneSpecificLong: DateTimeNamesHolderTrait<tz::MzSpecificLongV1Marker>;
-    type ZoneSpecificShort: DateTimeNamesHolderTrait<tz::MzSpecificShortV1Marker>;
-    type MetazoneLookup: DateTimeNamesHolderTrait<tz::MzPeriodV1Marker>;
+    type YearNames: NamesContainer<YearNamesV1Marker, FieldLength>;
+    type MonthNames: NamesContainer<MonthNamesV1Marker, (fields::Month, FieldLength)>;
+    type WeekdayNames: NamesContainer<WeekdayNamesV1Marker, (fields::Weekday, FieldLength)>;
+    type DayPeriodNames: NamesContainer<DayPeriodNamesV1Marker, FieldLength>;
+    type ZoneEssentials: NamesContainer<tz::EssentialsV1Marker, ()>;
+    type ZoneLocations: NamesContainer<tz::LocationsV1Marker, ()>;
+    type ZoneGenericLong: NamesContainer<tz::MzGenericLongV1Marker, ()>;
+    type ZoneGenericShort: NamesContainer<tz::MzGenericShortV1Marker, ()>;
+    type ZoneSpecificLong: NamesContainer<tz::MzSpecificLongV1Marker, ()>;
+    type ZoneSpecificShort: NamesContainer<tz::MzSpecificShortV1Marker, ()>;
+    type MetazoneLookup: NamesContainer<tz::MzPeriodV1Marker, ()>;
 }
 
-/// Helper trait for [`DateTimeNamesMarker`].
+/// Trait that associates a container for a payload parameterized by the given variables.
 #[allow(missing_docs)]
-pub trait DateTimeNamesHolderTrait<M: DynamicDataMarker>: UnstableSealed {
-    type Container<Variables: PartialEq + Copy + fmt::Debug>: MaybePayload<M, Variables>
-        + fmt::Debug;
+pub trait NamesContainer<M: DynamicDataMarker, Variables>: UnstableSealed
+where
+    Variables: PartialEq + Copy + fmt::Debug,
+{
+    type Container: MaybePayload<M, Variables> + fmt::Debug;
 }
 
-impl<M: DynamicDataMarker> DateTimeNamesHolderTrait<M> for () {
-    type Container<Variables: PartialEq + Copy + fmt::Debug> = ();
+impl<M: DynamicDataMarker, Variables> NamesContainer<M, Variables> for ()
+where
+    Variables: PartialEq + Copy + fmt::Debug,
+{
+    type Container = ();
 }
 
 macro_rules! impl_holder_trait {
     ($marker:path) => {
         impl UnstableSealed for $marker {}
-        impl DateTimeNamesHolderTrait<$marker> for $marker {
-            type Container<Variables: PartialEq + Copy + fmt::Debug> =
-                DataPayloadWithVariables<$marker, Variables>;
+        impl<Variables> NamesContainer<$marker, Variables> for $marker
+        where
+            Variables: PartialEq + Copy + fmt::Debug,
+        {
+            type Container = DataPayloadWithVariables<$marker, Variables>;
         }
     };
 }