Add ExportableDataPayload::eq_dyn (#3639)

components/calendar/src/provider.rs

@@ -119,7 +119,7 @@ impl FromStr for EraStartDate {
     "datetime/week_data@1",
     fallback_by = "region"
 ))]
-#[derive(Clone, Copy, Debug)]
+#[derive(Clone, Copy, Debug, PartialEq)]
 #[cfg_attr(
     feature = "datagen",
     derive(serde::Serialize, databake::Bake),

components/list/src/provider/mod.rs

@@ -48,7 +48,7 @@ const _: () = {
     OrListV1Marker = "list/or@1",
     UnitListV1Marker = "list/unit@1"
 )]
-#[derive(Clone, Debug)]
+#[derive(Clone, Debug, PartialEq)]
 #[cfg_attr(
     feature = "datagen",
     derive(serde::Serialize, databake::Bake),
@@ -116,10 +116,10 @@ impl<'data> ListFormatterPatternsV1<'data> {
 /// including in SemVer minor releases. While the serde representation of data structs is guaranteed
 /// to be stable, their Rust representation might not be. Use with caution.
 /// </div>
-#[derive(Clone, Debug, yoke::Yokeable, zerofrom::ZeroFrom)]
+#[derive(Clone, Debug, PartialEq, yoke::Yokeable, zerofrom::ZeroFrom)]
 #[cfg_attr(
     feature = "datagen",
-    derive(PartialEq, serde::Serialize, databake::Bake),
+    derive(serde::Serialize, databake::Bake),
     databake(path = icu_list::provider),
 )]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize))]
@@ -142,10 +142,10 @@ pub struct ConditionalListJoinerPattern<'data> {
 /// including in SemVer minor releases. While the serde representation of data structs is guaranteed
 /// to be stable, their Rust representation might not be. Use with caution.
 /// </div>
-#[derive(Clone, Debug, yoke::Yokeable, zerofrom::ZeroFrom)]
+#[derive(Clone, Debug, PartialEq, yoke::Yokeable, zerofrom::ZeroFrom)]
 #[cfg_attr(
     feature = "datagen",
-    derive(PartialEq, serde::Serialize, databake::Bake),
+    derive(serde::Serialize, databake::Bake),
     databake(path = icu_list::provider),
 )]
 pub struct SpecialCasePattern<'data> {

components/list/src/provider/serde_dfa.rs

@@ -22,7 +22,6 @@ pub struct SerdeDFA<'data> {
     pattern: Option<Cow<'data, str>>,
 }
 
-#[cfg(feature = "datagen")]
 impl PartialEq for SerdeDFA<'_> {
     fn eq(&self, other: &Self) -> bool {
         self.dfa_bytes == other.dfa_bytes

components/properties/src/provider/names.rs

@@ -186,7 +186,7 @@ impl NormalizedPropertyNameStr {
 /// including in SemVer minor releases. While the serde representation of data structs is guaranteed
 /// to be stable, their Rust representation might not be. Use with caution.
 /// </div>
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 #[icu_provider::data_struct(marker(
     GeneralCategoryMaskNameToValueV1Marker,
     "propnames/from/gcm@1",
@@ -213,7 +213,7 @@ pub struct PropertyValueNameToEnumMapV1<'data> {
 /// including in SemVer minor releases. While the serde representation of data structs is guaranteed
 /// to be stable, their Rust representation might not be. Use with caution.
 /// </div>
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 #[icu_provider::data_struct]
 #[cfg_attr(
     feature = "datagen", 
@@ -236,7 +236,7 @@ pub struct PropertyEnumToValueNameSparseMapV1<'data> {
 /// including in SemVer minor releases. While the serde representation of data structs is guaranteed
 /// to be stable, their Rust representation might not be. Use with caution.
 /// </div>
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 #[icu_provider::data_struct]
 #[cfg_attr(
     feature = "datagen", 
@@ -260,7 +260,7 @@ pub struct PropertyEnumToValueNameLinearMapV1<'data> {
 /// including in SemVer minor releases. While the serde representation of data structs is guaranteed
 /// to be stable, their Rust representation might not be. Use with caution.
 /// </div>
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq)]
 #[icu_provider::data_struct]
 #[cfg_attr(
     feature = "datagen", 

provider/core/src/datagen/payload.rs

@@ -2,10 +2,13 @@
 // called LICENSE at the top level of the ICU4X source tree
 // (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
 
+use core::any::Any;
+
 use crate::dynutil::UpcastDataPayload;
 use crate::prelude::*;
 use alloc::boxed::Box;
 use databake::{Bake, CrateEnv, TokenStream};
+use yoke::trait_hack::YokeTraitHack;
 use yoke::*;
 
 trait ExportableDataPayload {
@@ -14,11 +17,14 @@ trait ExportableDataPayload {
         &self,
         serializer: &mut dyn erased_serde::Serializer,
     ) -> Result<(), DataError>;
+    fn as_any(&self) -> &dyn Any;
+    fn eq_dyn(&self, other: &dyn ExportableDataPayload) -> bool;
 }
 
 impl<M: DataMarker> ExportableDataPayload for DataPayload<M>
 where
     for<'a> <M::Yokeable as Yokeable<'a>>::Output: Bake + serde::Serialize,
+    for<'a> YokeTraitHack<<M::Yokeable as Yokeable<'a>>::Output>: PartialEq,
 {
     fn bake_yoke(&self, ctx: &CrateEnv) -> TokenStream {
         self.get().bake(ctx)
@@ -34,6 +40,25 @@ where
             .map_err(|e| DataError::custom("Serde export").with_display_context(&e))?;
         Ok(())
     }
+
+    fn as_any(&self) -> &dyn Any {
+        self
+    }
+
+    fn eq_dyn(&self, other: &dyn ExportableDataPayload) -> bool {
+        match other.as_any().downcast_ref::<Self>() {
+            Some(downcasted) => (*self).eq(downcasted),
+            None => {
+                debug_assert!(
+                    false,
+                    "cannot compare ExportableDataPayloads of different types: self is {:?} but other is {:?}",
+                    self.type_id(),
+                    other.as_any().type_id(),
+                );
+                false
+            }
+        }
+    }
 }
 
 #[doc(hidden)] // exposed for make_exportable_provider
@@ -42,6 +67,12 @@ pub struct ExportBox {
     payload: Box<dyn ExportableDataPayload + Sync + Send>,
 }
 
+impl PartialEq for ExportBox {
+    fn eq(&self, other: &Self) -> bool {
+        self.payload.eq_dyn(&*other.payload)
+    }
+}
+
 impl core::fmt::Debug for ExportBox {
     fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
         f.debug_struct("ExportBox")
@@ -55,6 +86,7 @@ where
     M: DataMarker,
     M::Yokeable: Sync + Send,
     for<'a> <M::Yokeable as Yokeable<'a>>::Output: Bake + serde::Serialize,
+    for<'a> YokeTraitHack<<M::Yokeable as Yokeable<'a>>::Output>: PartialEq,
 {
     fn upcast(other: DataPayload<M>) -> DataPayload<ExportMarker> {
         DataPayload::from_owned(ExportBox {
@@ -143,3 +175,55 @@ pub struct ExportMarker {}
 impl DataMarker for ExportMarker {
     type Yokeable = ExportBox;
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::hello_world::*;
+
+    #[test]
+    fn test_compare_with_dyn() {
+        let payload1: DataPayload<HelloWorldV1Marker> = DataPayload::from_owned(HelloWorldV1 {
+            message: "abc".into(),
+        });
+        let payload2: DataPayload<HelloWorldV1Marker> = DataPayload::from_owned(HelloWorldV1 {
+            message: "abc".into(),
+        });
+        let payload3: DataPayload<HelloWorldV1Marker> = DataPayload::from_owned(HelloWorldV1 {
+            message: "def".into(),
+        });
+
+        assert!(payload1.eq_dyn(&payload2));
+        assert!(payload2.eq_dyn(&payload1));
+
+        assert!(!payload1.eq_dyn(&payload3));
+        assert!(!payload3.eq_dyn(&payload1));
+    }
+
+    #[test]
+    fn test_export_marker_partial_eq() {
+        let payload1: DataPayload<ExportMarker> =
+            UpcastDataPayload::upcast(DataPayload::<HelloWorldV1Marker>::from_owned(
+                HelloWorldV1 {
+                    message: "abc".into(),
+                },
+            ));
+        let payload2: DataPayload<ExportMarker> =
+            UpcastDataPayload::upcast(DataPayload::<HelloWorldV1Marker>::from_owned(
+                HelloWorldV1 {
+                    message: "abc".into(),
+                },
+            ));
+        let payload3: DataPayload<ExportMarker> =
+            UpcastDataPayload::upcast(DataPayload::<HelloWorldV1Marker>::from_owned(
+                HelloWorldV1 {
+                    message: "def".into(),
+                },
+            ));
+
+        assert_eq!(payload1, payload2);
+        assert_eq!(payload2, payload1);
+        assert_ne!(payload1, payload3);
+        assert_ne!(payload3, payload1);
+    }
+}