Add TimeZoneIdMapper to icu_timezone (#4774)

Fixes #4031
Replaces #4548

This new all-in-one type supports all of the time zone ID operations we
need, with some operations being asymptotically faster than others.

Not sure if we want to deprecate the old ones or keep them around, at
least IanaBcp47RoundTripMapper. It's not completely obsolete since it
has different performance characteristics.

---------

Co-authored-by: Robert Bastian <4706271+robertbastian@users.noreply.github.com>

CHANGELOG.md

@@ -26,6 +26,8 @@
     - Implement Hangul_Syllable_Type property (https://github.com/unicode-org/icu4x/pull/4885)
   - `icu_segmenter`
     - Fix Unicode 15.0 line breaking (https://github.com/unicode-org/icu4x/pull/4389)
+  - `icu_timezone`
+    - Added `TimeZoneIdMapper` to replace `IanaToBcp47Mapper` (https://github.com/unicode-org/icu4x/pull/4774)
 - Data model and providers
   - `icu_datagen`
     - Datagen shows elapsed time for keys that are slow to generate (https://github.com/unicode-org/icu4x/pull/4469)

components/datetime/src/time_zone.rs

@@ -72,7 +72,7 @@ where
 ///
 /// ```
 /// use icu::calendar::DateTime;
-/// use icu::timezone::{CustomTimeZone, MetazoneCalculator, IanaToBcp47Mapper};
+/// use icu::timezone::{CustomTimeZone, MetazoneCalculator, TimeZoneIdMapper};
 /// use icu::datetime::{DateTimeError, time_zone::TimeZoneFormatter};
 /// use icu::locid::locale;
 /// use tinystr::tinystr;
@@ -87,7 +87,7 @@ where
 /// // Set up the Metazone calculator, time zone ID mapper,
 /// // and the DateTime to use in calculation
 /// let mzc = MetazoneCalculator::new();
-/// let mapper = IanaToBcp47Mapper::new();
+/// let mapper = TimeZoneIdMapper::new();
 /// let datetime = DateTime::try_new_iso_datetime(2022, 8, 29, 0, 0, 0)
 ///     .unwrap();
 ///
@@ -102,7 +102,7 @@ where
 ///
 /// // "uschi" - has metazone symbol data for generic_non_location_short
 /// let mut time_zone = "-0600".parse::<CustomTimeZone>().unwrap();
-/// time_zone.time_zone_id = mapper.as_borrowed().get("America/Chicago");
+/// time_zone.time_zone_id = mapper.as_borrowed().iana_to_bcp47("America/Chicago");
 /// time_zone.maybe_calculate_metazone(&mzc, &datetime);
 /// assert_writeable_eq!(
 ///     tzf.format(&time_zone),

components/timezone/Cargo.toml

@@ -24,7 +24,7 @@ displaydoc = { workspace = true }
 icu_calendar = { workspace = true }
 icu_provider = { workspace = true, features = ["macros"] }
 tinystr = { workspace = true, features = ["alloc", "zerovec"] }
-zerotrie = { workspace = true, features = ["yoke", "zerofrom"] }
+zerotrie = { workspace = true, features = ["alloc", "yoke", "zerofrom"] }
 zerovec = { workspace = true, features = ["derive", "yoke"] }
 
 databake = { workspace = true, optional = true, features = ["derive"] }

components/timezone/src/iana_ids.rs

@@ -2,6 +2,8 @@
 // called LICENSE at the top level of the ICU4X source tree
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
+#![allow(deprecated)] // all APIS in here are deprecated
+
 use crate::error::TimeZoneError;
 use crate::provider::names::*;
 use crate::TimeZoneBcp47Id;
@@ -36,6 +38,7 @@ use icu_provider::prelude::*;
 /// );
 /// ```
 #[derive(Debug)]
+#[deprecated(since = "1.5.0", note = "use `TimeZoneIdMapper` instead")]
 pub struct IanaToBcp47Mapper {
     data: DataPayload<IanaToBcp47MapV1Marker>,
 }
@@ -98,6 +101,7 @@ impl IanaToBcp47Mapper {
 /// A borrowed wrapper around IANA-to-BCP47 time zone data, returned by
 /// [`IanaToBcp47Mapper::as_borrowed()`]. More efficient to query.
 #[derive(Debug)]
+#[deprecated(since = "1.5.0", note = "use `TimeZoneIdMapper` instead")]
 pub struct IanaToBcp47MapperBorrowed<'a> {
     data: &'a IanaToBcp47MapV1<'a>,
 }
@@ -167,6 +171,7 @@ impl<'a> IanaToBcp47MapperBorrowed<'a> {
 /// assert_eq!(iana_id, Some("Asia/Kolkata"))
 /// ```
 #[derive(Debug)]
+#[deprecated(since = "1.5.0", note = "use `TimeZoneIdMapper` instead")]
 pub struct IanaBcp47RoundTripMapper {
     data1: DataPayload<IanaToBcp47MapV1Marker>,
     data2: DataPayload<Bcp47ToIanaMapV1Marker>,
@@ -243,6 +248,7 @@ impl IanaBcp47RoundTripMapper {
 /// A borrowed wrapper around IANA-BCP47 time zone data, returned by
 /// [`IanaBcp47RoundTripMapper::as_borrowed()`]. More efficient to query.
 #[derive(Debug)]
+#[deprecated(since = "1.5.0", note = "use `TimeZoneIdMapper` instead")]
 pub struct IanaBcp47RoundTripMapperBorrowed<'a> {
     data1: &'a IanaToBcp47MapV1<'a>,
     data2: &'a Bcp47ToIanaMapV1<'a>,