Move the baked exporter into its own crate (#5009)

#4721 

The `icu_provider_datagen` crate can be a runtime dependency for baked
data, in order to expose dependencies that are required for databake
operation (I'm thinking zerotrie and writeable).

The former `icu_datagen::baked_exporter` module is this new crate's
`exporter` module, behind an `export` feature, analogous to
`icu_provider_blob` and `icu_provider_fs`.

This is also a better home for the `test-baked-source` test, because in
`icu_datagen`, if the baked source wouldn't build, `make-testdata` also
wouldn't, which is annoying (@younies).

CONTRIBUTING.md

@@ -42,7 +42,7 @@ To build all code paths, improve build times in VSCode, and prevent locking the
 }
 ```
 
-Note: the path in `ICU4X_DATA_DIR` is relative to `provider/baked/*/src/lib.rs` and it causes VSCode to build ICU4X with only the `und` locale. This reduces build times but also makes some tests fail; to run them normally, run `cargo test --all-features` on the command line.
+Note: the path in `ICU4X_DATA_DIR` is relative to `provider/data/*/src/lib.rs` and it causes VSCode to build ICU4X with only the `und` locale. This reduces build times but also makes some tests fail; to run them normally, run `cargo test --all-features` on the command line.
 
 ## Contributing a Pull Request
 

Cargo.toml

@@ -34,6 +34,7 @@ members = [
 
     # Provider
     "provider/adapters",
+    "provider/baked",
     "provider/blob",
     "provider/core",
     "provider/core/macros",
@@ -42,18 +43,18 @@ members = [
     "provider/registry",
 
     # Baked data
-    "provider/baked/calendar",
-    "provider/baked/casemap",
-    "provider/baked/collator",
-    "provider/baked/datetime",
-    "provider/baked/decimal",
-    "provider/baked/list",
-    "provider/baked/locale",
-    "provider/baked/normalizer",
-    "provider/baked/plurals",
-    "provider/baked/properties",
-    "provider/baked/segmenter",
-    "provider/baked/timezone",
+    "provider/data/calendar",
+    "provider/data/casemap",
+    "provider/data/collator",
+    "provider/data/datetime",
+    "provider/data/decimal",
+    "provider/data/list",
+    "provider/data/locale",
+    "provider/data/normalizer",
+    "provider/data/plurals",
+    "provider/data/properties",
+    "provider/data/segmenter",
+    "provider/data/timezone",
 
     # Utils
     "utils/bies",
@@ -150,24 +151,25 @@ icu_datagen = { version = "~1.5.0", path = "provider/datagen", default-features
 icu_provider = { version = "~1.5.0", path = "provider/core", default-features = false }
 icu_provider_macros = { version = "~1.5.0", path = "provider/core/macros", default-features = false }
 icu_provider_adapters = { version = "~1.5.0", path = "provider/adapters", default-features = false }
+icu_provider_baked = { version = "~1.5.0", path = "provider/baked", default-features = false }
 icu_provider_blob = { version = "~1.5.0", path = "provider/blob", default-features = false }
 icu_provider_fs = { version = "~1.5.0", path = "provider/fs/", default-features = false }
 icu_registry = { version = "~1.5.0", path = "provider/registry/", default-features = false }
 
 # Baked data
-icu_calendar_data = { version = "~1.5.0", path = "provider/baked/calendar", default-features = false }
-icu_casemap_data = { version = "~1.5.0", path = "provider/baked/casemap", default-features = false }
-icu_collator_data = { version = "~1.5.0", path = "provider/baked/collator", default-features = false }
-icu_datetime_data = { version = "~1.5.0", path = "provider/baked/datetime", default-features = false }
-icu_decimal_data = { version = "~1.5.0", path = "provider/baked/decimal", default-features = false }
-icu_list_data = { version = "~1.5.0", path = "provider/baked/list", default-features = false }
-icu_locale_data = { version = "~1.5.0", path = "provider/baked/locale", default-features = false }
-icu_normalizer_data = { version = "~1.5.0", path = "provider/baked/normalizer", default-features = false }
-icu_plurals_data = { version = "~1.5.0", path = "provider/baked/plurals", default-features = false }
-icu_properties_data = { version = "~1.5.0", path = "provider/baked/properties", default-features = false }
-icu_segmenter_data = { version = "~1.5.0", path = "provider/baked/segmenter", default-features = false }
-icu_timezone_data = { version = "~1.5.0", path = "provider/baked/timezone", default-features = false }
-icu_experimental_data = { version = "~0.1.0", path = "provider/baked/experimental", default-features = false }
+icu_calendar_data = { version = "~1.5.0", path = "provider/data/calendar", default-features = false }
+icu_casemap_data = { version = "~1.5.0", path = "provider/data/casemap", default-features = false }
+icu_collator_data = { version = "~1.5.0", path = "provider/data/collator", default-features = false }
+icu_datetime_data = { version = "~1.5.0", path = "provider/data/datetime", default-features = false }
+icu_decimal_data = { version = "~1.5.0", path = "provider/data/decimal", default-features = false }
+icu_list_data = { version = "~1.5.0", path = "provider/data/list", default-features = false }
+icu_locale_data = { version = "~1.5.0", path = "provider/data/locale", default-features = false }
+icu_normalizer_data = { version = "~1.5.0", path = "provider/data/normalizer", default-features = false }
+icu_plurals_data = { version = "~1.5.0", path = "provider/data/plurals", default-features = false }
+icu_properties_data = { version = "~1.5.0", path = "provider/data/properties", default-features = false }
+icu_segmenter_data = { version = "~1.5.0", path = "provider/data/segmenter", default-features = false }
+icu_timezone_data = { version = "~1.5.0", path = "provider/data/timezone", default-features = false }
+icu_experimental_data = { version = "~0.1.0", path = "provider/data/experimental", default-features = false }
 
 # Utils
 bies = { version = "0.2.2", path = "utils/bies", default-features = false }

provider/baked/Cargo.toml

@@ -0,0 +1,33 @@
+# This file is part of ICU4X. For terms of use, please see the file
+# called LICENSE at the top level of the ICU4X source tree
+# (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
+
+[package]
+name = "icu_provider_baked"
+
+version.workspace = true
+rust-version.workspace = true
+authors.workspace = true
+edition.workspace = true
+repository.workspace = true
+homepage.workspace = true
+license.workspace = true
+categories.workspace = true
+include.workspace = true
+
+[dependencies]
+icu_provider = { workspace = true }
+
+crlify = { workspace = true, optional = true }
+databake = { workspace = true, optional = true}
+icu_registry = { workspace = true, optional = true }
+itertools = { workspace = true, optional = true }
+log = { workspace = true, optional = true }
+proc-macro2 = { workspace = true, optional = true }
+
+[dev-dependencies]
+icu_provider = { path = "../core", features = ["datagen"] }
+icu_datagen = { path = "../datagen" }
+
+[features]
+export = ["dep:icu_registry", "dep:databake", "dep:proc-macro2", "dep:itertools", "dep:crlify", "dep:log", "icu_provider/datagen"]