Merge pull request toml-rs#467 from epage/value

fix(ser)!: Clarify its `toml_edit`'s serializer is for `Value`

crates/toml_edit/src/easy/mod.rs

@@ -64,7 +64,7 @@
 //!
 //! This means that you can use Serde to deserialize/serialize the
 //! [`Value`] type as well as the [`Datetime`][crate::Datetime] type in this crate. You can also
-//! use the [`Deserializer`], [`Serializer`], or [`Value`] type itself to act as
+//! use the [`Deserializer`], [`ValueSerializer`], or [`Value`] type itself to act as
 //! a deserializer/serializer for arbitrary types.
 //!
 //! An example of deserializing with TOML is:
@@ -146,7 +146,7 @@ pub use crate::toml;
 #[doc(no_inline)]
 pub use de::{from_document, from_slice, from_str, Deserializer};
 #[doc(no_inline)]
-pub use ser::{to_document, to_string, to_string_pretty, to_vec, Serializer};
+pub use ser::{to_document, to_string, to_string_pretty, to_vec, ValueSerializer};
 pub use serde_spanned::Spanned;
 #[doc(no_inline)]
 pub use value::Value;

crates/toml_edit/src/easy/value.rs

@@ -8,6 +8,7 @@ use std::str::FromStr;
 
 use serde::de::IntoDeserializer as _;
 use serde::Deserialize as _;
+use serde::Serialize as _;
 
 pub use crate::easy::datetime::*;
 use crate::easy::map::Entry;
@@ -51,8 +52,7 @@ impl Value {
     where
         T: serde::ser::Serialize,
     {
-        let item = super::ser::to_item(&value)?;
-        let value = item.into_value().expect("`to_item` only generates values");
+        let value = value.serialize(super::ValueSerializer::new())?;
         let value = value.into_deserializer();
         let target = Self::deserialize(value)?;
         Ok(target)
@@ -71,8 +71,7 @@ impl Value {
     where
         T: serde::de::DeserializeOwned,
     {
-        let item = super::ser::to_item(&self)?;
-        let value = item.into_value().expect("`to_item` only generates values");
+        let value = (&self).serialize(super::ValueSerializer::new())?;
         let value = value.into_deserializer();
         let target = T::deserialize(value)?;
         Ok(target)
@@ -243,7 +242,8 @@ impl std::fmt::Display for Value {
             | Value::Float(..)
             | Value::Boolean(..)
             | Value::Datetime(..)
-            | Value::Array(..) => crate::ser::to_item(self)
+            | Value::Array(..) => self
+                .serialize(super::ValueSerializer::new())
                 .map_err(|_| std::fmt::Error)?
                 .fmt(f),
             Value::Table(_) => crate::ser::to_string_pretty(self)

crates/toml_edit/src/ser/array.rs

@@ -1,11 +1,11 @@
 use super::Error;
 
 #[doc(hidden)]
-pub struct SerializeItemArray {
+pub struct SerializeValueArray {
     values: Vec<crate::Item>,
 }
 
-impl SerializeItemArray {
+impl SerializeValueArray {
     pub(crate) fn new() -> Self {
         Self { values: Vec::new() }
     }
@@ -17,28 +17,26 @@ impl SerializeItemArray {
     }
 }
 
-impl serde::ser::SerializeSeq for SerializeItemArray {
-    type Ok = crate::Item;
+impl serde::ser::SerializeSeq for SerializeValueArray {
+    type Ok = crate::Value;
     type Error = Error;
 
     fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
     where
         T: serde::ser::Serialize,
     {
-        let value = value.serialize(super::ItemSerializer {})?;
-        self.values.push(value);
+        let value = value.serialize(super::ValueSerializer {})?;
+        self.values.push(crate::Item::Value(value));
         Ok(())
     }
 
     fn end(self) -> Result<Self::Ok, Self::Error> {
-        Ok(crate::Item::Value(crate::Value::Array(
-            crate::Array::with_vec(self.values),
-        )))
+        Ok(crate::Value::Array(crate::Array::with_vec(self.values)))
     }
 }
 
-impl serde::ser::SerializeTuple for SerializeItemArray {
-    type Ok = crate::Item;
+impl serde::ser::SerializeTuple for SerializeValueArray {
+    type Ok = crate::Value;
     type Error = Error;
 
     fn serialize_element<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
@@ -53,8 +51,8 @@ impl serde::ser::SerializeTuple for SerializeItemArray {
     }
 }
 
-impl serde::ser::SerializeTupleVariant for SerializeItemArray {
-    type Ok = crate::Item;
+impl serde::ser::SerializeTupleVariant for SerializeValueArray {
+    type Ok = crate::Value;
     type Error = Error;
 
     fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>
@@ -69,8 +67,8 @@ impl serde::ser::SerializeTupleVariant for SerializeItemArray {
     }
 }
 
-impl serde::ser::SerializeTupleStruct for SerializeItemArray {
-    type Ok = crate::Item;
+impl serde::ser::SerializeTupleStruct for SerializeValueArray {
+    type Ok = crate::Value;
     type Error = Error;
 
     fn serialize_field<T: ?Sized>(&mut self, value: &T) -> Result<(), Error>

crates/toml_edit/src/ser/mod.rs

@@ -3,13 +3,12 @@
 //! This module contains all the Serde support for serializing Rust structures into TOML.
 
 mod array;
-mod item;
 mod key;
 mod pretty;
 mod table;
+mod value;
 
 pub(crate) use array::*;
-pub(crate) use item::*;
 pub(crate) use key::*;
 pub(crate) use table::*;
 
@@ -145,7 +144,7 @@ where
 /// Serialize the given data structure as a "pretty" String of TOML.
 ///
 /// This is identical to `to_string` except the output string has a more
-/// "pretty" output. See `Serializer::pretty` for more details.
+/// "pretty" output. See `ValueSerializer::pretty` for more details.
 pub fn to_string_pretty<T: ?Sized>(value: &T) -> Result<String, Error>
 where
     T: serde::ser::Serialize,
@@ -162,22 +161,12 @@ pub fn to_document<T: ?Sized>(value: &T) -> Result<crate::Document, Error>
 where
     T: serde::ser::Serialize,
 {
-    let item = to_item(value)?;
+    let value = value.serialize(ValueSerializer::new())?;
+    let item = crate::Item::Value(value);
     let root = item
         .into_table()
         .map_err(|_| ErrorKind::UnsupportedType(None))?;
     Ok(root.into())
 }
 
-/// Serialize the given data structure into a TOML data structure
-///
-/// This would allow custom formatting to be applied, mixing with format preserving edits, etc.
-pub fn to_item<T: ?Sized>(value: &T) -> Result<crate::Item, Error>
-where
-    T: serde::ser::Serialize,
-{
-    let item = value.serialize(Serializer::new())?;
-    Ok(item)
-}
-
-pub use item::ItemSerializer as Serializer;
+pub use value::ValueSerializer;

crates/toml_edit/src/ser/table.rs

@@ -1,11 +1,11 @@
 use super::{Error, ErrorKind, KeySerializer};
 
 #[doc(hidden)]
-pub struct SerializeItemTable {
+pub struct SerializeValueTable {
     inner: SerializeKeyValuePairs,
 }
 
-impl SerializeItemTable {
+impl SerializeValueTable {
     pub(crate) fn new() -> Self {
         Self {
             inner: SerializeKeyValuePairs::new(),
@@ -19,8 +19,8 @@ impl SerializeItemTable {
     }
 }
 
-impl serde::ser::SerializeMap for SerializeItemTable {
-    type Ok = crate::Item;
+impl serde::ser::SerializeMap for SerializeValueTable {
+    type Ok = crate::Value;
     type Error = Error;
 
     fn serialize_key<T: ?Sized>(&mut self, input: &T) -> Result<(), Self::Error>
@@ -38,16 +38,14 @@ impl serde::ser::SerializeMap for SerializeItemTable {
     }
 
     fn end(self) -> Result<Self::Ok, Self::Error> {
-        self.inner.end().map(|items| {
-            crate::Item::Value(crate::Value::InlineTable(crate::InlineTable::with_pairs(
-                items,
-            )))
-        })
+        self.inner
+            .end()
+            .map(|items| crate::Value::InlineTable(crate::InlineTable::with_pairs(items)))
     }
 }
 
-impl serde::ser::SerializeStruct for SerializeItemTable {
-    type Ok = crate::Item;
+impl serde::ser::SerializeStruct for SerializeValueTable {
+    type Ok = crate::Value;
     type Error = Error;
 
     fn serialize_field<T: ?Sized>(
@@ -62,11 +60,9 @@ impl serde::ser::SerializeStruct for SerializeItemTable {
     }
 
     fn end(self) -> Result<Self::Ok, Self::Error> {
-        self.inner.end().map(|items| {
-            crate::Item::Value(crate::Value::InlineTable(crate::InlineTable::with_pairs(
-                items,
-            )))
-        })
+        self.inner
+            .end()
+            .map(|items| crate::Value::InlineTable(crate::InlineTable::with_pairs(items)))
     }
 }
 
@@ -107,20 +103,21 @@ impl serde::ser::SerializeMap for SerializeKeyValuePairs {
     where
         T: serde::ser::Serialize,
     {
-        let res = value.serialize(super::ItemSerializer {});
-        let item = match res {
-            Ok(item) => item,
+        let res = value.serialize(super::ValueSerializer {});
+        match res {
+            Ok(item) => {
+                let key = self.key.take().unwrap();
+                let kv = crate::table::TableKeyValue::new(
+                    crate::Key::new(&key),
+                    crate::Item::Value(item),
+                );
+                self.items.insert(key, kv);
+            }
             Err(e) => {
                 if e.kind != ErrorKind::UnsupportedNone {
                     return Err(e);
                 }
-                crate::Item::None
             }
-        };
-        if !item.is_none() {
-            let key = self.key.take().unwrap();
-            let kv = crate::table::TableKeyValue::new(crate::Key::new(&key), item);
-            self.items.insert(key, kv);
         }
         Ok(())
     }
@@ -142,20 +139,21 @@ impl serde::ser::SerializeStruct for SerializeKeyValuePairs {
     where
         T: serde::ser::Serialize,
     {
-        let res = value.serialize(super::ItemSerializer {});
-        let item = match res {
-            Ok(item) => item,
+        let res = value.serialize(super::ValueSerializer {});
+        match res {
+            Ok(item) => {
+                let kv = crate::table::TableKeyValue::new(
+                    crate::Key::new(key),
+                    crate::Item::Value(item),
+                );
+                self.items.insert(crate::InternalString::from(key), kv);
+            }
             Err(e) => {
                 if e.kind != ErrorKind::UnsupportedNone {
                     return Err(e);
                 }
-                crate::Item::None
             }
         };
-        if !item.is_none() {
-            let kv = crate::table::TableKeyValue::new(crate::Key::new(key), item);
-            self.items.insert(crate::InternalString::from(key), kv);
-        }
         Ok(())
     }
 

crates/toml_edit/src/ser/item.rs → crates/toml_edit/src/ser/value.rs

@@ -11,28 +11,28 @@ use super::{Error, ErrorKind};
 /// which is passed in when creating the serializer itself.
 #[derive(Default)]
 #[non_exhaustive]
-pub struct ItemSerializer {}
+pub struct ValueSerializer {}
 
-impl ItemSerializer {
+impl ValueSerializer {
     /// Creates a new serializer generate a TOML document.
     pub fn new() -> Self {
         Self {}
     }
 }
 
-impl serde::ser::Serializer for ItemSerializer {
-    type Ok = crate::Item;
+impl serde::ser::Serializer for ValueSerializer {
+    type Ok = crate::Value;
     type Error = Error;
-    type SerializeSeq = super::SerializeItemArray;
-    type SerializeTuple = super::SerializeItemArray;
-    type SerializeTupleStruct = super::SerializeItemArray;
-    type SerializeTupleVariant = super::SerializeItemArray;
-    type SerializeMap = super::SerializeItemTable;
-    type SerializeStruct = super::SerializeItemTable;
+    type SerializeSeq = super::SerializeValueArray;
+    type SerializeTuple = super::SerializeValueArray;
+    type SerializeTupleStruct = super::SerializeValueArray;
+    type SerializeTupleVariant = super::SerializeValueArray;
+    type SerializeMap = super::SerializeValueTable;
+    type SerializeStruct = super::SerializeValueTable;
     type SerializeStructVariant = serde::ser::Impossible<Self::Ok, Self::Error>;
 
     fn serialize_bool(self, v: bool) -> Result<Self::Ok, Self::Error> {
-        Ok(crate::Item::Value(v.into()))
+        Ok(v.into())
     }
 
     fn serialize_i8(self, v: i8) -> Result<Self::Ok, Self::Error> {
@@ -48,7 +48,7 @@ impl serde::ser::Serializer for ItemSerializer {
     }
 
     fn serialize_i64(self, v: i64) -> Result<Self::Ok, Self::Error> {
-        Ok(crate::Item::Value(v.into()))
+        Ok(v.into())
     }
 
     fn serialize_u8(self, v: u8) -> Result<Self::Ok, Self::Error> {
@@ -72,7 +72,7 @@ impl serde::ser::Serializer for ItemSerializer {
     }
 
     fn serialize_f64(self, v: f64) -> Result<Self::Ok, Self::Error> {
-        Ok(crate::Item::Value(v.into()))
+        Ok(v.into())
     }
 
     fn serialize_char(self, v: char) -> Result<Self::Ok, Self::Error> {
@@ -81,7 +81,7 @@ impl serde::ser::Serializer for ItemSerializer {
     }
 
     fn serialize_str(self, v: &str) -> Result<Self::Ok, Self::Error> {
-        Ok(crate::Item::Value(v.into()))
+        Ok(v.into())
     }
 
     fn serialize_bytes(self, value: &[u8]) -> Result<Self::Ok, Self::Error> {
@@ -143,8 +143,8 @@ impl serde::ser::Serializer for ItemSerializer {
 
     fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
         let serializer = match len {
-            Some(len) => super::SerializeItemArray::with_capacity(len),
-            None => super::SerializeItemArray::new(),
+            Some(len) => super::SerializeValueArray::with_capacity(len),
+            None => super::SerializeValueArray::new(),
         };
         Ok(serializer)
     }
@@ -173,8 +173,8 @@ impl serde::ser::Serializer for ItemSerializer {
 
     fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
         let serializer = match len {
-            Some(len) => super::SerializeItemTable::with_capacity(len),
-            None => super::SerializeItemTable::new(),
+            Some(len) => super::SerializeValueTable::with_capacity(len),
+            None => super::SerializeValueTable::new(),
         };
         Ok(serializer)
     }