feat: Introduce to_string and other top-level functions for serde_json drop-in replacement

src/error.rs

@@ -5,7 +5,7 @@
 use jiter::JsonValue;
 
 /// A content-less variant of the [JsonValue] enum, used for reporting errors, see [MerdeJsonError::MismatchedType].
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 #[non_exhaustive]
 pub enum JsonFieldType {
     /// The JSON value is `null`.
@@ -78,6 +78,9 @@ pub enum MerdeJsonError {
 
     /// While parsing a [time::Date] or [time::Time], we got an error.
     InvalidDateTimeValue,
+
+    /// An I/O error occurred.
+    Io(std::io::Error),
 }
 
 impl From<jiter::JsonError> for MerdeJsonError {
@@ -86,6 +89,12 @@ impl From<jiter::JsonError> for MerdeJsonError {
     }
 }
 
+impl From<std::io::Error> for MerdeJsonError {
+    fn from(e: std::io::Error) -> Self {
+        MerdeJsonError::Io(e)
+    }
+}
+
 impl std::fmt::Display for MerdeJsonError {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -120,6 +129,9 @@ impl std::fmt::Display for MerdeJsonError {
             MerdeJsonError::InvalidDateTimeValue => {
                 write!(f, "Invalid date/time value")
             }
+            MerdeJsonError::Io(e) => {
+                write!(f, "I/O error: {}", e)
+            }
         }
     }
 }

src/lib.rs

@@ -1189,16 +1189,43 @@ where
     }
 }
 
-/// Parses a JSON byte string into a [JsonValue].
-pub fn from_slice(data: &[u8]) -> Result<jiter::JsonValue<'_>, MerdeJsonError> {
+/// Deserialize an instance of type `T` from bytes of JSON text.
+pub fn from_slice(data: &[u8]) -> Result<JsonValue<'_>, MerdeJsonError> {
     Ok(jiter::JsonValue::parse(data, false)?)
 }
 
-/// Parses a JSON string into a [JsonValue].
-pub fn from_str(s: &str) -> Result<jiter::JsonValue<'_>, MerdeJsonError> {
+/// Deserialize an instance of type `T` from a string of JSON text.
+pub fn from_str(s: &str) -> Result<JsonValue<'_>, MerdeJsonError> {
     from_slice(s.as_bytes())
 }
 
+/// Interpret a `JsonValue` as an instance of type `T`.
+pub fn from_value<'src: 'val, 'val, T>(value: &'val JsonValue<'src>) -> Result<T, MerdeJsonError>
+where
+    T: JsonDeserialize<'src, 'val>,
+{
+    T::json_deserialize(Some(value))
+}
+
+/// Serialize the given data structure as a String of JSON.
+pub fn to_string<T: JsonSerialize>(value: &T) -> String {
+    value.to_json_string()
+}
+
+/// Serialize the given data structure as a JSON byte vector.
+pub fn to_vec<T: JsonSerialize>(value: &T) -> Vec<u8> {
+    value.to_json_bytes()
+}
+
+/// Serialize the given data structure as JSON into the I/O stream.
+pub fn to_writer<W, T>(mut writer: impl std::io::Write, value: &T) -> std::io::Result<()>
+where
+    T: JsonSerialize,
+{
+    let bytes = value.to_json_bytes();
+    writer.write_all(&bytes)
+}
+
 /// Allow turning a value into an "owned" variant, which can then be
 /// returned, moved, etc.
 ///