[lib] Implement serializing/deserializing UserPreferences

src/user_preferences/mod.rs

@@ -6,12 +6,14 @@
 
 pub mod v0;
 mod error;
+use core::convert::TryFrom;
 pub use error::ParseError;
 
 use crate::user_preferences::v0::UserPreferencesV0;
 use crate::{InstanceSettings, Pronoun, WeightedTable};
 
 use data_encoding::BASE32_NOPAD;
+use serde;
 
 /// A user's preferences for the probabilities of certain pronouns
 ///
@@ -25,7 +27,8 @@ use data_encoding::BASE32_NOPAD;
 /// Because parsing a prefstring must be done in relation to an [`InstanceSettings`], the
 /// `UserPreferences` struct shares a lifetime with the settings it was created with.
 #[non_exhaustive]
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+#[serde(try_from = "Intermediary", into = "Intermediary")]
 pub enum UserPreferences {
 	V0(v0::UserPreferencesV0)
 }
@@ -142,6 +145,25 @@ impl Preference for UserPreferences {
 	}
 }
 
+/// Serves as an intermediary for serializing and deserializing [`Preference`] objects
+#[derive(serde::Serialize, serde::Deserialize)]
+#[serde(transparent)]
+struct Intermediary(String);
+
+impl From<UserPreferences> for Intermediary {
+	fn from(prefs: UserPreferences) -> Intermediary {
+		Intermediary(prefs.as_prefstring())
+	}
+}
+
+impl TryFrom<Intermediary> for UserPreferences {
+	type Error = ParseError;
+
+	fn try_from(prefs: Intermediary) -> Result<UserPreferences, ParseError> {
+		UserPreferences::from_prefstring(prefs.0.as_str())
+	}
+}
+
 #[cfg(test)]
 mod test {
 	use super::*;

src/user_preferences/v0.rs

@@ -17,7 +17,7 @@ use std::{
 /// See the [prefstring specification][1] for more information about how this is interpretted.
 ///
 /// [1]: https://fem.mint.lgbt/Emi/PronounsToday/raw/branch/main/doc/User-Preference-String-Spec.txt
-#[derive(Debug, PartialEq, Eq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct UserPreferencesV0 {
 	pub default_weight: u8,
 	pub default_enabled: bool,