Refactoring icu-data-provider crate.

Cargo.toml

@@ -2,7 +2,6 @@
 
 members = [
     "components/data-provider",
-    "components/data-provider-json",
     "components/icu",
     "components/icu4x",
     "components/uniset",

components/data-provider/Cargo.toml

@@ -15,28 +15,16 @@ include = [
 ]
 
 [features]
-default = ["std"]
-std = ["serde/std", "no-std-compat/std"]
+# Enable InvariantDataProvider, a locale-agnostic data provider.
+invariant = []
 
 [dependencies]
 icu-locale = { path = "../locale" }
+tinystr = "0.3"
+erased-serde = "0.3"
+smallstr = { version = "0.2", features = ["serde"] }
+downcast-rs = "1.2"
+serde = { version = "1.0", features = ["derive"] }
 
-[dependencies.smallstr]
-version = "0.2.0"
-default-features = false
-features = ["serde"]
-
-[dependencies.downcast-rs]
-version = "1.1.1"
-
-[dependencies.async-trait]
-version = "0.1.30"
-
-[dependencies.serde]
-version = "1.0"
-default-features = false
-features = ["derive", "alloc"]
-
-[dependencies.no-std-compat]
-version = "0.4.0"
-features = ["alloc"]
+[dev-dependencies]
+serde_json = "1.0"

components/data-provider/src/helpers.rs → components/data-provider/src/cloneable_any.rs

@@ -1,13 +1,16 @@
-use std::prelude::v1::*;
-
 use downcast_rs::impl_downcast;
 use downcast_rs::Downcast;
 use std::fmt::Debug;
 
+#[cfg(feature = "erased-serde")]
+use erased_serde;
+
 // Please do not to make this trait public, because it is easy to use incorrectly. It is fine as
 // an internal auto-implemented trait.
-pub(super) trait CloneableAny: Debug + Downcast {
+pub(super) trait CloneableAny: Debug + Downcast + erased_serde::Serialize {
     fn clone_into_box(&self) -> Box<dyn CloneableAny>;
+
+    fn as_serialize(&self) -> &dyn erased_serde::Serialize;
 }
 
 impl ToOwned for dyn CloneableAny {
@@ -19,10 +22,14 @@ impl ToOwned for dyn CloneableAny {
 }
 
 // Implement CloneableAny for all 'static types implementing Clone.
-impl<S: 'static + Clone + Debug> CloneableAny for S {
+impl<T: 'static + Clone + Debug + erased_serde::Serialize> CloneableAny for T {
     fn clone_into_box(&self) -> Box<dyn CloneableAny> {
         Box::new(self.clone())
     }
+
+    fn as_serialize(&self) -> &dyn erased_serde::Serialize {
+        self
+    }
 }
 
 // Adds the Downcast methods to all 'static types implementing CloneableAny.