From: Lizzy Fleckenstein <eliasfleckenstein@web.de>
Date: Wed, 1 Feb 2023 14:19:44 +0000 (+0100)
Subject: Add serialize_as_map
X-Git-Url: https://git.lizzy.rs/?a=commitdiff_plain;p=enumset.git

Add serialize_as_map
---

diff --git a/enumset/tests/serde.rs b/enumset/tests/serde.rs
index c67ebf3..105d674 100644
--- a/enumset/tests/serde.rs
+++ b/enumset/tests/serde.rs
@@ -16,6 +16,13 @@ pub enum ListEnum {
     A, B, C, D, E, F, G, H,
 }
 
+#[derive(Serialize, Deserialize, EnumSetType, Debug)]
+#[enumset(serialize_as_map)]
+#[serde(crate="serde2")]
+pub enum MapEnum {
+    A, B, C, D, E, F, G, H,
+}
+
 #[derive(EnumSetType, Debug)]
 #[enumset(serialize_repr = "u128")]
 pub enum ReprEnum {
@@ -77,14 +84,19 @@ fn test_deny_unknown() {
 fn test_json_reprs() {
     assert_eq!(ListEnum::A | ListEnum::C | ListEnum::F,
                serde_json::from_str::<EnumSet<ListEnum>>(r#"["A","C","F"]"#).unwrap());
+    assert_eq!(MapEnum::A | MapEnum::C | MapEnum::F,
+               serde_json::from_str::<EnumSet<MapEnum>>(r#"{"A":true,"C":true,"F":true}"#).unwrap());
     assert_eq!(ReprEnum::A | ReprEnum::C | ReprEnum::D,
                serde_json::from_str::<EnumSet<ReprEnum>>("13").unwrap());
     assert_eq!(r#"["A","C","F"]"#,
                serde_json::to_string(&(ListEnum::A | ListEnum::C | ListEnum::F)).unwrap());
+    assert_eq!(r#"{"A":true,"C":true,"F":true}"#,
+               serde_json::to_string(&(MapEnum::A | MapEnum::C | MapEnum::F)).unwrap());
     assert_eq!("13",
                serde_json::to_string(&(ReprEnum::A | ReprEnum::C | ReprEnum::D)).unwrap());
 }
 
 tests!(list_enum, serde_test_simple!(ListEnum, !0));
+tests!(map_enum, serde_test_simple!(MapEnum, !0));
 tests!(repr_enum, serde_test!(ReprEnum, 16));
 tests!(deny_unknown_enum, serde_test_simple!(DenyUnknownEnum, 16));
diff --git a/enumset_derive/src/lib.rs b/enumset_derive/src/lib.rs
index 88ac367..04fc0df 100644
--- a/enumset_derive/src/lib.rs
+++ b/enumset_derive/src/lib.rs
@@ -24,6 +24,7 @@ struct EnumsetAttrs {
     #[darling(default)]
     repr: Option<String>,
     serialize_as_list: bool,
+    serialize_as_map: bool,
     serialize_deny_unknown: bool,
     #[darling(default)]
     serialize_repr: Option<String>,
@@ -72,6 +73,8 @@ struct EnumSetInfo {
     no_super_impls: bool,
     /// Serialize the enum as a list.
     serialize_as_list: bool,
+    /// Serialize the enum as a map.
+    serialize_as_map: bool,
     /// Disallow unknown bits while deserializing the enum.
     serialize_deny_unknown: bool,
 }
@@ -94,6 +97,7 @@ impl EnumSetInfo {
             no_ops: attrs.no_ops,
             no_super_impls: attrs.no_super_impls,
             serialize_as_list: attrs.serialize_as_list,
+            serialize_as_map: attrs.serialize_as_map,
             serialize_deny_unknown: attrs.serialize_deny_unknown,
         }
     }
@@ -375,6 +379,45 @@ fn enum_set_type_impl(info: EnumSetInfo) -> SynTokenStream {
                 de.deserialize_seq(Visitor)
             }
         }
+    } else if info.serialize_as_map {
+        let expecting_str = format!("a map from {} to bool", name);
+        quote! {
+            fn serialize<S: #serde::Serializer>(
+                set: #enumset::EnumSet<#name>, ser: S,
+            ) -> #core::result::Result<S::Ok, S::Error> {
+                use #serde::ser::SerializeMap;
+                let mut map = ser.serialize_map(#core::prelude::v1::Some(set.len()))?;
+                for bit in set {
+                    map.serialize_entry(&bit, &true)?;
+                }
+                map.end()
+            }
+            fn deserialize<'de, D: #serde::Deserializer<'de>>(
+                de: D,
+            ) -> #core::result::Result<#enumset::EnumSet<#name>, D::Error> {
+                struct Visitor;
+                impl <'de> #serde::de::Visitor<'de> for Visitor {
+                    type Value = #enumset::EnumSet<#name>;
+                    fn expecting(
+                        &self, formatter: &mut #core::fmt::Formatter,
+                    ) -> #core::fmt::Result {
+                        write!(formatter, #expecting_str)
+                    }
+                    fn visit_map<A>(
+                        mut self, mut map: A,
+                    ) -> #core::result::Result<Self::Value, A::Error> where
+                        A: #serde::de::MapAccess<'de>
+                    {
+                        let mut accum = #enumset::EnumSet::<#name>::new();
+                        while let #core::prelude::v1::Some((val, true)) = map.next_entry::<#name, bool>()? {
+                            accum |= val;
+                        }
+                        #core::prelude::v1::Ok(accum)
+                    }
+                }
+                de.deserialize_map(Visitor)
+            }
+        }
     } else {
         let serialize_repr = info.serde_repr();
         let check_unknown = if info.serialize_deny_unknown {