Add IANA-to-BCP47 and reverse mappings

components/datetime/src/time_zone.rs

@@ -74,20 +74,22 @@ where
 ///
 /// ```
 /// use icu::calendar::DateTime;
-/// use icu::timezone::{CustomTimeZone, MetazoneCalculator};
+/// use icu::timezone::{CustomTimeZone, MetazoneCalculator, IanaToBcp47Mapper};
 /// use icu::datetime::{DateTimeError, time_zone::TimeZoneFormatter};
 /// use icu::locid::locale;
 /// use tinystr::tinystr;
 /// use writeable::assert_writeable_eq;
 ///
 /// // Set up the time zone. Note: the inputs here are
 /// //   1. The GMT offset
-/// //   2. The BCP-47 time zone ID
+/// //   2. The IANA time zone ID
 /// //   3. A datetime (for metazone resolution)
 /// //   4. Note: we do not need the zone variant because of `load_generic_*()`
 ///
-/// // Set up the Metazone calculator and the DateTime to use in calculation
+/// // 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 datetime = DateTime::try_new_iso_datetime(2022, 8, 29, 0, 0, 0)
 ///     .unwrap();
 ///
@@ -102,7 +104,7 @@ where
 ///
 /// // "uschi" - has metazone symbol data for generic_non_location_short
 /// let mut time_zone = "-0600".parse::<CustomTimeZone>().unwrap();
-/// time_zone.time_zone_id = Some(tinystr!(8, "uschi").into());
+/// time_zone.time_zone_id = mapper.as_borrowed().get("America/Chicago");
 /// time_zone.maybe_calculate_metazone(&mzc, &datetime);
 /// assert_writeable_eq!(
 ///     tzf.format(&time_zone),

components/timezone/Cargo.toml

@@ -25,6 +25,7 @@ icu_calendar = { workspace = true }
 icu_locid = { workspace = true }
 icu_provider = { workspace = true, features = ["macros"] }
 tinystr = { workspace = true, features = ["alloc", "zerovec"] }
+zerotrie = { workspace = true, features = ["yoke", "zerofrom"] }
 zerovec = { workspace = true, features = ["derive", "yoke"] }
 
 databake = { workspace = true, optional = true, features = ["derive"] }
@@ -38,6 +39,6 @@ icu = { workspace = true }
 [features]
 default = ["compiled_data"]
 std = ["icu_calendar/std", "icu_locid/std", "icu_provider/std"]
-serde = ["dep:serde", "zerovec/serde", "tinystr/serde", "icu_provider/serde"]
-datagen = ["serde", "dep:databake", "zerovec/databake", "tinystr/databake"]
+serde = ["dep:serde", "zerovec/serde", "zerotrie/serde", "tinystr/serde", "icu_provider/serde"]
+datagen = ["serde", "dep:databake", "zerovec/databake", "zerotrie/databake", "tinystr/databake"]
 compiled_data = ["dep:icu_timezone_data"]

components/timezone/data/config.json

@@ -1,7 +1,9 @@
 {
   "keys": {
     "explicit": [
-      "time_zone/metazone_period@1"
+      "time_zone/metazone_period@1",
+      "time_zone/iana_to_bcp47@1",
+      "time_zone/bcp47_to_iana@1"
     ]
   },
   "fallback": "runtime",

components/timezone/src/error.rs

@@ -20,6 +20,9 @@ pub enum TimeZoneError {
     /// The time zone offset was invalid.
     #[displaydoc("Failed to parse time-zone offset")]
     InvalidOffset,
+    /// The data name checksums do not match (data from different sources?)
+    #[displaydoc("Data checksums to not match (mismatched data sources?)")]
+    MismatchedChecksums,
     /// An error originating inside of the [data provider](icu_provider).
     #[displaydoc("{0}")]
     Data(DataError),