Transform some tuple structs to structs with named fields for serialization purposes

Author: robknight

src/frontend/mod.rs

@@ -34,8 +34,30 @@ pub enum PodClass {
 
 // An Origin, which represents a reference to an ancestor POD.
 #[derive(Clone, Debug, PartialEq, Eq, h::Hash, Default, Serialize, Deserialize)]
+#[serde(into = "OriginSerdeHelper", from = "OriginSerdeHelper")]
 pub struct Origin(pub PodClass, pub PodId);
 
+#[derive(Serialize, Deserialize)]
+struct OriginSerdeHelper {
+    pod_class: PodClass,
+    pod_id: PodId,
+}
+
+impl From<Origin> for OriginSerdeHelper {
+    fn from(origin: Origin) -> Self {
+        OriginSerdeHelper {
+            pod_class: origin.0,
+            pod_id: origin.1,
+        }
+    }
+}
+
+impl From<OriginSerdeHelper> for Origin {
+    fn from(helper: OriginSerdeHelper) -> Self {
+        Origin(helper.pod_class, helper.pod_id)
+    }
+}
+
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
 pub enum Value {
     // Serde cares about the order of the enum variants, with untagged variants
@@ -239,6 +261,7 @@ impl SignedPod {
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, h::Hash, Serialize, Deserialize)]
+#[serde(into = "AnchoredKeySerdeHelper", from = "AnchoredKeySerdeHelper")]
 pub struct AnchoredKey(pub Origin, pub String);
 
 impl From<AnchoredKey> for middleware::AnchoredKey {
@@ -247,6 +270,32 @@ impl From<AnchoredKey> for middleware::AnchoredKey {
     }
 }
 
+// Tuple structs get serialized to bare JSON arrays, which is not very
+// user-friendly. This helper struct allows us to serialize AnchoredKeys
+// into a structure with named fields.
+#[derive(Serialize, Deserialize)]
+struct AnchoredKeySerdeHelper {
+    origin: Origin,
+    key: String,
+}
+
+// Convert from AnchoredKey to the helper for serialization
+impl From<AnchoredKey> for AnchoredKeySerdeHelper {
+    fn from(ak: AnchoredKey) -> Self {
+        AnchoredKeySerdeHelper {
+            origin: ak.0,
+            key: ak.1,
+        }
+    }
+}
+
+// Convert from the helper back to AnchoredKey for deserialization
+impl From<AnchoredKeySerdeHelper> for AnchoredKey {
+    fn from(helper: AnchoredKeySerdeHelper) -> Self {
+        AnchoredKey(helper.origin, helper.key)
+    }
+}
+
 #[derive(Debug)]
 pub struct MainPodBuilder {
     pub params: Params,

src/frontend/statement.rs

@@ -20,8 +20,30 @@ impl fmt::Display for StatementArg {
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(into = "StatementSerdeHelper", from = "StatementSerdeHelper")]
 pub struct Statement(pub Predicate, pub Vec<StatementArg>);
 
+#[derive(Serialize, Deserialize)]
+struct StatementSerdeHelper {
+    predicate: Predicate,
+    args: Vec<StatementArg>,
+}
+
+impl From<Statement> for StatementSerdeHelper {
+    fn from(statement: Statement) -> Self {
+        StatementSerdeHelper {
+            predicate: statement.0,
+            args: statement.1,
+        }
+    }
+}
+
+impl From<StatementSerdeHelper> for Statement {
+    fn from(helper: StatementSerdeHelper) -> Self {
+        Statement(helper.predicate, helper.args)
+    }
+}
+
 impl From<(&SignedPod, &str)> for Statement {
     fn from((pod, key): (&SignedPod, &str)) -> Self {
         // TODO: TryFrom.

src/middleware/custom.rs

@@ -391,6 +391,7 @@ impl CustomPredicateRef {
 }
 
 #[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(tag = "type", content = "value")]
 pub enum Predicate {
     Native(NativePredicate),
     BatchSelf(usize),