chore: Release serde_sjson version 1.2.0

* feat/prepare-publish:
  Add publishing command
  Improve package metadata
  Add documentation

CHANGELOG.adoc

@@ -1,59 +0,0 @@
-= Changelog
-:toc:
-:toclevels: 1
-:idprefix:
-:idseparator: -
-
-== [Unreleased]
-
-=== Added
-
-=== Fixed
-
-== [v1.0.0] - 2023-03-10
-
-=== Added
-
-- implement literal strings
-
-=== Fixed
-
-- fix serializing strings containing `:`
-- fix serializing certain escaped characters
-
-== [v0.2.4] - 2023-03-01
-
-=== Fixed
-
-- fix incorrect parsing of unquoted strings
-
-== [v0.2.3] - 2023-02-24
-
-=== Fixed
-
-- support backslashes in delimited strings
-
-== [v0.2.2] - 2023-02-18
-
-=== Fixed
-
-- fix deserialization failing on arrays and objects in some cases
-
-== [v0.2.1] - 2022-12-28
-
-=== Fixed
-
-- fix serializing Unicode
-
-== [v0.2.0] - 2022-11-25
-
-=== Added
-
-* parsing & deserialization
-
-== [v0.1.0] - 2022-11-18
-
-=== Added
-
-* initial release
-* serialization

CHANGELOG.md

@@ -0,0 +1,69 @@
+# Changelog
+
+<!-- next-header -->
+
+## [Unreleased] - ReleaseDate
+
+## [1.2.0] - 2024-03-21
+
+### Added
+
+- publishing to [crates.io](https://crates.io)
+
+## [v1.1.0] - 2024-03-21
+
+### Added
+
+- implement serializing into generic `io::Write`
+
+### Fixed
+
+- fix parsing CRLF
+
+## [v1.0.0] - 2023-03-10
+
+### Added
+
+- implement literal strings
+
+### Fixed
+
+- fix serializing strings containing `:`
+- fix serializing certain escaped characters
+
+## [v0.2.4] - 2023-03-01
+
+### Fixed
+
+- fix incorrect parsing of unquoted strings
+
+## [v0.2.3] - 2023-02-24
+
+### Fixed
+
+- support backslashes in delimited strings
+
+## [v0.2.2] - 2023-02-18
+
+### Fixed
+
+- fix deserialization failing on arrays and objects in some cases
+
+## [v0.2.1] - 2022-12-28
+
+### Fixed
+
+- fix serializing Unicode
+
+## [v0.2.0] - 2022-11-25
+
+### Added
+
+* parsing & deserialization
+
+## [v0.1.0] - 2022-11-18
+
+### Added
+
+* initial release
+* serialization

Cargo.toml

@@ -1,15 +1,27 @@
 [package]
 name = "serde_sjson"
-version = "1.0.0"
+version = "1.2.0"
+authors = ["Lucas Schwiderski"]
+categories = ["encoding", "parser-implementations"]
+description = "An SJSON serialization file format"
+documentation = "https://docs.rs/serde_sjson"
 edition = "2021"
 keywords = ["serde", "serialization", "sjson"]
-description = "An SJSON serialization file format"
+license-file = "LICENSE"
-categories = ["encoding", "parser-implementations"]
+repository = "https://github.com/sclu1034/serde_sjson"
+exclude = [
+    ".github/",
+    ".ci/",
+    "Justfile"
+]
 
 [dependencies]
-nom = "7.1.3"
+nom = "7"
-nom_locate = "4.1.0"
+nom_locate = "4.1"
-serde = { version = "1.0.154", default-features = false }
+serde = { version = "1.0", default-features = false }
 
 [dev-dependencies]
-serde = { version = "1.0.154", features = ["derive"] }
+serde = { version = "1.0.194", features = ["derive"] }
+
+[badges]
+maintenance = { status = "passively-maintained" }

Justfile

@@ -1,12 +1,26 @@
 project := "serde_sjson"
 default := "run"
 
+build *ARGS:
+    cargo build {{ARGS}}
+    cargo readme > README.md
+
 run *ARGS:
     cargo run -- {{ARGS}}
 
 test *ARGS:
     cargo test {{ARGS}}
 
+doc:
+    cargo doc --no-deps
+    cargo readme > README.md
+
+serve-doc port='8000': doc
+    python3 -m http.server {{port}} --directory target/doc
+
+release version execute='':
+    cargo release --sign --allow-branch master {{ if execute != "" { '-x' } else { '' } }} {{version}}
+
 coverage *ARGS:
     RUSTFLAGS="-C instrument-coverage" cargo test --tests {{ARGS}} || true
     cargo profdata -- merge -sparse default*.profraw -o {{project}}.profdata

README.adoc

@@ -1,13 +0,0 @@
-= Serde SJSON
-:idprefix:
-:idseparator:
-:toc: macro
-:toclevels: 1
-:!toc-title:
-:caution-caption: :fire:
-:important-caption: :exclamtion:
-:note-caption: :paperclip:
-:tip-caption: :bulb:
-:warning-caption: :warning:
-
-A __ser__ialization/__de__serialization library for __Simplified JSON__, specifically, the Bitsquid/Stingray flavor.

README.md

@@ -0,0 +1,69 @@
+# serde_sjson
+
+A **ser**ialization/**de**serialization library for Simplified JSON,
+the Bitsquid/Stingray flavor of JSON.
+
+## Usage
+
+### Serializing
+
+```rust
+use serde::Serialize;
+use serde_sjson::Result;
+
+#[derive(Serialize)]
+struct Person {
+    name: String,
+    age: u8,
+    friends: Vec<String>,
+}
+
+fn main() -> Result<()> {
+    let data = Person {
+        name: String::from("Marc"),
+        age: 21,
+        friends: vec![String::from("Jessica"), String::from("Paul")],
+    };
+
+    let s = serde_sjson::to_string(&data)?;
+
+    println!("{}", s);
+
+    Ok(())
+}
+```
+
+### Deserializing
+
+```rust
+use serde::Deserialize;
+use serde_sjson::Result;
+
+#[derive(Deserialize)]
+struct Person {
+    name: String,
+    age: u8,
+    friends: Vec<String>,
+}
+
+fn main() -> Result<()> {
+    let sjson = r#"
+    name = Marc
+    age = 21
+    friends = [
+        Jessica
+        Paul
+    ]"#;
+
+    let data: Person = serde_sjson::from_str(sjson)?;
+
+    println!(
+        "{} is {} years old and has {} friends.",
+        data.name,
+        data.age,
+        data.friends.len()
+    );
+
+    Ok(())
+}
+```

README.tpl

@@ -0,0 +1,3 @@
+# {{crate}}
+
+{{readme}}

release.toml

@@ -0,0 +1,5 @@
+pre-release-replacements = [
+    {file="CHANGELOG.md", search="Unreleased", replace="{{version}}"},
+    {file="CHANGELOG.md", search="ReleaseDate", replace="{{date}}"},
+    {file="CHANGELOG.md", search="<!-- next-header -->", replace="<!-- next-header -->\n\n## [Unreleased] - ReleaseDate", exactly=1},
+]

src/de.rs

@@ -5,6 +5,7 @@ use serde::Deserialize;
 use crate::error::{Error, ErrorCode, Result};
 use crate::parser::*;
 
+/// A container for deserializing Rust values from SJSON.
 pub struct Deserializer<'de> {
     input: Span<'de>,
     is_top_level: bool,
@@ -12,7 +13,7 @@ pub struct Deserializer<'de> {
 
 impl<'de> Deserializer<'de> {
     #![allow(clippy::should_implement_trait)]
-    pub fn from_str(input: &'de str) -> Self {
+    pub(crate) fn from_str(input: &'de str) -> Self {
         Self {
             input: Span::from(input),
             is_top_level: true,
@@ -65,6 +66,8 @@ impl<'de> Deserializer<'de> {
     }
 }
 
+/// Deserializes an SJSON string to a Rust value.
+#[inline]
 pub fn from_str<'a, T>(input: &'a str) -> Result<T>
 where
     T: Deserialize<'a>,

src/error.rs

@@ -1,9 +1,12 @@
-use std::fmt;
+use std::{fmt, io};
 
 use crate::parser::Token;
 
+/// An alias for a `Result` with `serde_sjson::Error`.
 pub type Result<T> = std::result::Result<T, Error>;
 
+/// A type encapsulating the different errors that might occurr
+/// during serialization or deserialization.
 #[derive(PartialEq)]
 pub struct Error {
     inner: Box<ErrorImpl>,
@@ -38,6 +41,7 @@ pub(crate) enum ErrorCode {
     ExpectedTopLevelObject,
     ExpectedValue,
     TrailingCharacters,
+    NonFiniteFloat,
 }
 
 impl fmt::Display for ErrorCode {
@@ -64,6 +68,7 @@ impl fmt::Display for ErrorCode {
             ErrorCode::ExpectedTopLevelObject => f.write_str("expected object at the top level"),
             ErrorCode::ExpectedValue => f.write_str("expected a value"),
             ErrorCode::TrailingCharacters => f.write_str("unexpected trailing characters"),
+            ErrorCode::NonFiniteFloat => f.write_str("got infinite floating point number"),
         }
     }
 }
@@ -166,3 +171,9 @@ impl Error {
         }
     }
 }
+
+impl From<io::Error> for Error {
+    fn from(err: io::Error) -> Self {
+        Self::new(ErrorCode::Message(format!("{}", err)), 0, 0, None)
+    }
+}

src/lib.rs

@@ -1,3 +1,71 @@
+//! A **ser**ialization/**de**serialization library for Simplified JSON,
+//! the Bitsquid/Stingray flavor of JSON.
+//!
+//! # Usage
+//!
+//! ## Serializing
+//!
+//! ```
+//! use serde::Serialize;
+//! use serde_sjson::Result;
+//!
+//! #[derive(Serialize)]
+//! struct Person {
+//!     name: String,
+//!     age: u8,
+//!     friends: Vec<String>,
+//! }
+//!
+//! fn main() -> Result<()> {
+//!     let data = Person {
+//!         name: String::from("Marc"),
+//!         age: 21,
+//!         friends: vec![String::from("Jessica"), String::from("Paul")],
+//!     };
+//!
+//!     let s = serde_sjson::to_string(&data)?;
+//!
+//!     println!("{}", s);
+//!
+//!     Ok(())
+//! }
+//! ```
+//!
+//! ## Deserializing
+//!
+//! ```
+//! use serde::Deserialize;
+//! use serde_sjson::Result;
+//!
+//! #[derive(Deserialize)]
+//! struct Person {
+//!     name: String,
+//!     age: u8,
+//!     friends: Vec<String>,
+//! }
+//!
+//! fn main() -> Result<()> {
+//!     let sjson = r#"
+//!     name = Marc
+//!     age = 21
+//!     friends = [
+//!         Jessica
+//!         Paul
+//!     ]"#;
+//!
+//!     let data: Person = serde_sjson::from_str(sjson)?;
+//!
+//!     println!(
+//!         "{} is {} years old and has {} friends.",
+//!         data.name,
+//!         data.age,
+//!         data.friends.len()
+//!     );
+//!
+//!     Ok(())
+//! }
+//! ```
+
 mod de;
 mod error;
 mod parser;
@@ -5,4 +73,4 @@ mod ser;
 
 pub use de::{from_str, Deserializer};
 pub use error::{Error, Result};
-pub use ser::{to_string, Serializer};
+pub use ser::{to_string, to_vec, to_writer, Serializer};

src/parser.rs

@@ -39,7 +39,9 @@ fn null(input: Span) -> IResult<Span, ()> {
 }
 
 fn separator(input: Span) -> IResult<Span, &str> {
-    map(alt((tag(","), tag("\n"))), |val: Span| *val.fragment())(input)
+    map(alt((tag(","), tag("\n"), tag("\r\n"))), |val: Span| {
+        *val.fragment()
+    })(input)
 }
 
 fn bool(input: Span) -> IResult<Span, bool> {
@@ -436,4 +438,21 @@ packages = [
         let sjson = format!(r#""{}""#, text);
         check_parse_result(sjson, [Token::String(String::from(text))]);
     }
+
+    // Regression test for #10
+    #[test]
+    fn parse_crlf_separator() {
+        let sjson = "foo = 1\r\nbar = 2";
+        check_parse_result(
+            sjson,
+            [
+                Token::String(String::from("foo")),
+                Token::Equals,
+                Token::Integer(1),
+                Token::String(String::from("bar")),
+                Token::Equals,
+                Token::Integer(2),
+            ],
+        );
+    }
 }

src/ser.rs

@@ -1,36 +1,80 @@
+use std::io;
+
 use serde::Serialize;
 
 use crate::error::{Error, ErrorCode, Result};
 
 // TODO: Make configurable
-const INDENT: &str = "  ";
+const INDENT: [u8; 2] = [0x20, 0x20];
 
-pub struct Serializer {
+/// A container for serializing Rust values into SJSON.
+pub struct Serializer<W> {
     // The current indentation level
     level: usize,
-    // The output string
+    writer: W,
-    output: String,
 }
 
+/// Serializes a value into a generic `io::Write`.
+#[inline]
+pub fn to_writer<T, W>(writer: &mut W, value: &T) -> Result<()>
+where
+    W: io::Write,
+    T: Serialize,
+{
+    let mut serializer = Serializer::new(writer);
+    value.serialize(&mut serializer)
+}
+
+/// Serializes a value into a byte vector.
+#[inline]
+pub fn to_vec<T>(value: &T) -> Result<Vec<u8>>
+where
+    T: Serialize,
+{
+    let mut vec = Vec::with_capacity(128);
+    to_writer(&mut vec, value)?;
+    Ok(vec)
+}
+
+/// Serializes a value into a string.
+#[inline]
 pub fn to_string<T>(value: &T) -> Result<String>
 where
     T: Serialize,
 {
-    let mut serializer = Serializer {
+    let vec = to_vec(value)?;
-        level: 0,
+    let string = if cfg!(debug_assertions) {
-        output: String::new(),
+        String::from_utf8(vec).expect("We do not emit invalid UTF-8")
+    } else {
+        unsafe { String::from_utf8_unchecked(vec) }
     };
-    value.serialize(&mut serializer)?;
+    Ok(string)
-    Ok(serializer.output)
 }
 
-impl Serializer {
+impl<W> Serializer<W>
-    fn add_indent(&mut self) {
+where
-        for _ in 0..self.level.saturating_sub(1) {
+    W: io::Write,
-            self.output += INDENT;
+{
-        }
+    /// Creates a new `Serializer`.
+    pub fn new(writer: W) -> Self {
+        Self { level: 0, writer }
     }
 
+    #[inline]
+    fn write(&mut self, bytes: impl AsRef<[u8]>) -> Result<()> {
+        self.writer.write_all(bytes.as_ref()).map_err(Error::from)
+    }
+
+    #[inline]
+    fn add_indent(&mut self) -> Result<()> {
+        for _ in 0..self.level.saturating_sub(1) {
+            self.write(INDENT)?;
+        }
+
+        Ok(())
+    }
+
+    #[inline]
     fn ensure_top_level_struct(&self) -> Result<()> {
         if self.level == 0 {
             return Err(Error::new(ErrorCode::ExpectedTopLevelObject, 0, 0, None));
@@ -40,7 +84,10 @@ impl Serializer {
     }
 }
 
-impl<'a> serde::ser::Serializer for &'a mut Serializer {
+impl<'a, W> serde::ser::Serializer for &'a mut Serializer<W>
+where
+    W: io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -54,7 +101,7 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
 
     fn serialize_bool(self, v: bool) -> Result<Self::Ok> {
         self.ensure_top_level_struct()?;
-        self.output += if v { "true" } else { "false" };
+        self.write(if v { "true" } else { "false" })?;
         Ok(())
     }
 
@@ -72,8 +119,7 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
 
     fn serialize_i64(self, v: i64) -> Result<Self::Ok> {
         self.ensure_top_level_struct()?;
-        self.output += &v.to_string();
+        self.serialize_str(&format!("{}", v))
-        Ok(())
     }
 
     fn serialize_u8(self, v: u8) -> Result<Self::Ok> {
@@ -90,33 +136,25 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
 
     fn serialize_u64(self, v: u64) -> Result<Self::Ok> {
         self.ensure_top_level_struct()?;
-        self.output += &v.to_string();
+        self.serialize_str(&format!("{}", v))
-        Ok(())
     }
 
     fn serialize_f32(self, v: f32) -> Result<Self::Ok> {
-        if v.is_finite() {
+        self.serialize_f64(v.into())
-            self.serialize_f64(v.into())
-        } else {
-            self.ensure_top_level_struct()?;
-            self.output += "null";
-            Ok(())
-        }
     }
 
     fn serialize_f64(self, v: f64) -> Result<Self::Ok> {
         self.ensure_top_level_struct()?;
-        if v.is_finite() {
+        if !v.is_finite() {
-            self.output += &v.to_string();
+            return Err(Error::new(ErrorCode::NonFiniteFloat, 0, 0, None));
-        } else {
-            self.output += "null";
         }
-        Ok(())
+
+        self.serialize_str(&format!("{}", v))
     }
 
     fn serialize_char(self, v: char) -> Result<Self::Ok> {
         let mut buf = [0; 4];
-        self.serialize_str(v.encode_utf8(&mut buf))
+        self.serialize_bytes(v.encode_utf8(&mut buf).as_bytes())
     }
 
     fn serialize_str(self, v: &str) -> Result<Self::Ok> {
@@ -126,45 +164,52 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
             v.is_empty() || v.contains([' ', '\n', '\r', '\t', '=', '\'', '"', '\\', ':']);
 
         if needs_quotes {
-            self.output += "\"";
+            self.write(b"\"")?;
 
+            // Since we've added a layer of quotes, we now need to escape
+            // certain characters.
             for c in v.chars() {
                 match c {
                     '\t' => {
-                        self.output.push('\\');
+                        self.write(b"\\")?;
-                        self.output.push('t');
+                        self.write(b"t")?;
                     }
                     '\n' => {
-                        self.output.push('\\');
+                        self.write(b"\\")?;
-                        self.output.push('n');
+                        self.write(b"n")?;
                     }
                     '\r' => {
-                        self.output.push('\\');
+                        self.write(b"\\")?;
-                        self.output.push('r');
+                        self.write(b"r")?;
                     }
                     '"' => {
-                        self.output.push('\\');
+                        self.write(b"\\")?;
-                        self.output.push('"');
+                        self.write(b"\"")?;
                     }
                     '\\' => {
-                        self.output.push('\\');
+                        self.write(b"\\")?;
-                        self.output.push('\\');
+                        self.write(b"\\")?;
                     }
                     c => {
-                        self.output.push(c);
+                        self.serialize_char(c)?;
                     }
                 };
             }
 
-            self.output += "\"";
+            self.write(b"\"")?;
         } else {
-            self.output += v;
+            self.write(v.as_bytes())?;
         }
+
         Ok(())
     }
 
-    fn serialize_bytes(self, _v: &[u8]) -> Result<Self::Ok> {
+    fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok> {
-        todo!()
+        self.ensure_top_level_struct()?;
+        // For now we assume that the byte array contains
+        // valid SJSON.
+        // TODO: Turn this into an actual array of encoded bytes.
+        self.write(v)
     }
 
     fn serialize_none(self) -> Result<Self::Ok> {
@@ -184,8 +229,7 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
 
     fn serialize_unit(self) -> Result<Self::Ok> {
         self.ensure_top_level_struct()?;
-        self.output += "null";
+        self.write(b"null")
-        Ok(())
     }
 
     fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok> {
@@ -223,19 +267,18 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
     {
         self.ensure_top_level_struct()?;
 
-        self.output += "{ ";
+        self.write(b"{ ")?;
         variant.serialize(&mut *self)?;
-        self.output += " = ";
+        self.write(b" = ")?;
         value.serialize(&mut *self)?;
-        self.output += " }\n";
+        self.write(b" }")
-        Ok(())
     }
 
     // Serialize the start of a sequence.
     fn serialize_seq(self, _len: Option<usize>) -> Result<Self::SerializeSeq> {
         self.ensure_top_level_struct()?;
 
-        self.output += "[\n";
+        self.write(b"[\n")?;
         self.level += 1;
         Ok(self)
     }
@@ -266,7 +309,7 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
 
         variant.serialize(&mut *self)?;
 
-        self.output += " = [\n";
+        self.write(b" = [\n")?;
         self.level += 1;
 
         Ok(self)
@@ -274,7 +317,7 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
 
     fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
         if self.level > 0 {
-            self.output += "{\n";
+            self.write(b"{\n")?;
         }
         self.level += 1;
         Ok(self)
@@ -296,7 +339,7 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
 
         variant.serialize(&mut *self)?;
 
-        self.output += " = {\n";
+        self.write(b" = {\n")?;
         self.level += 1;
 
         Ok(self)
@@ -310,7 +353,10 @@ impl<'a> serde::ser::Serializer for &'a mut Serializer {
     }
 }
 
-impl<'a> serde::ser::SerializeSeq for &'a mut Serializer {
+impl<'a, W> serde::ser::SerializeSeq for &'a mut Serializer<W>
+where
+    W: io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -318,23 +364,22 @@ impl<'a> serde::ser::SerializeSeq for &'a mut Serializer {
     where
         T: Serialize,
     {
-        self.add_indent();
+        self.add_indent()?;
         value.serialize(&mut **self)?;
-        if !self.output.ends_with('\n') {
+        self.write(b"\n")
-            self.output += "\n";
-        }
-        Ok(())
     }
 
     fn end(self) -> Result<Self::Ok> {
         self.level -= 1;
-        self.add_indent();
+        self.add_indent()?;
-        self.output += "]\n";
+        self.write(b"]")
-        Ok(())
     }
 }
 
-impl<'a> serde::ser::SerializeTuple for &'a mut Serializer {
+impl<'a, W> serde::ser::SerializeTuple for &'a mut Serializer<W>
+where
+    W: io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -342,23 +387,22 @@ impl<'a> serde::ser::SerializeTuple for &'a mut Serializer {
     where
         T: Serialize,
     {
-        self.add_indent();
+        self.add_indent()?;
         value.serialize(&mut **self)?;
-        if !self.output.ends_with('\n') {
+        self.write(b"\n")
-            self.output += "\n";
-        }
-        Ok(())
     }
 
     fn end(self) -> Result<Self::Ok> {
         self.level -= 1;
-        self.add_indent();
+        self.add_indent()?;
-        self.output += "]\n";
+        self.write(b"]")
-        Ok(())
     }
 }
 
-impl<'a> serde::ser::SerializeTupleStruct for &'a mut Serializer {
+impl<'a, W> serde::ser::SerializeTupleStruct for &'a mut Serializer<W>
+where
+    W: io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -366,23 +410,22 @@ impl<'a> serde::ser::SerializeTupleStruct for &'a mut Serializer {
     where
         T: Serialize,
     {
-        self.add_indent();
+        self.add_indent()?;
         value.serialize(&mut **self)?;
-        if !self.output.ends_with('\n') {
+        self.write(b"\n")
-            self.output += "\n";
-        }
-        Ok(())
     }
 
     fn end(self) -> Result<Self::Ok> {
         self.level -= 1;
-        self.add_indent();
+        self.add_indent()?;
-        self.output += "]\n";
+        self.write(b"]")
-        Ok(())
     }
 }
 
-impl<'a> serde::ser::SerializeTupleVariant for &'a mut Serializer {
+impl<'a, W> serde::ser::SerializeTupleVariant for &'a mut Serializer<W>
+where
+    W: io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -390,28 +433,31 @@ impl<'a> serde::ser::SerializeTupleVariant for &'a mut Serializer {
     where
         T: Serialize,
     {
-        self.add_indent();
+        self.add_indent()?;
         value.serialize(&mut **self)?;
-        if !self.output.ends_with('\n') {
+        self.write(b"\n")
-            self.output += "\n";
-        }
-        Ok(())
     }
 
     fn end(self) -> Result<Self::Ok> {
         self.level -= 1;
-        self.add_indent();
+        self.add_indent()?;
-        self.output += "]\n";
+        self.write(b"]\n")?;
+
         self.level -= 1;
+
         if self.level > 0 {
-            self.add_indent();
+            self.add_indent()?;
-            self.output += "}\n";
+            self.write(b"}")?;
         }
+
         Ok(())
     }
 }
 
-impl<'a> serde::ser::SerializeMap for &'a mut Serializer {
+impl<'a, W> serde::ser::SerializeMap for &'a mut Serializer<W>
+where
+    W: io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -419,7 +465,7 @@ impl<'a> serde::ser::SerializeMap for &'a mut Serializer {
     where
         T: Serialize,
     {
-        self.add_indent();
+        self.add_indent()?;
         key.serialize(&mut **self)
     }
 
@@ -430,25 +476,25 @@ impl<'a> serde::ser::SerializeMap for &'a mut Serializer {
         // It doesn't make a difference where the `=` is added. But doing it here
         // means `serialize_key` is only a call to a different function, which should
         // have greater optimization potential for the compiler.
-        self.output += " = ";
+        self.write(b" = ")?;
         value.serialize(&mut **self)?;
-        if !self.output.ends_with('\n') {
+        self.write(b"\n")
-            self.output += "\n";
-        }
-        Ok(())
     }
 
     fn end(self) -> Result<Self::Ok> {
         if self.level > 1 {
             self.level -= 1;
-            self.add_indent();
+            self.add_indent()?;
-            self.output += "}\n";
+            self.write(b"}")?;
         }
         Ok(())
     }
 }
 
-impl<'a> serde::ser::SerializeStruct for &'a mut Serializer {
+impl<'a, W> serde::ser::SerializeStruct for &'a mut Serializer<W>
+where
+    W: io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -456,29 +502,29 @@ impl<'a> serde::ser::SerializeStruct for &'a mut Serializer {
     where
         T: Serialize,
     {
-        self.add_indent();
+        self.add_indent()?;
         key.serialize(&mut **self)?;
 
-        self.output += " = ";
+        self.write(b" = ")?;
 
         value.serialize(&mut **self)?;
-        if !self.output.ends_with('\n') {
+        self.write(b"\n")
-            self.output += "\n";
-        }
-        Ok(())
     }
 
     fn end(self) -> Result<Self::Ok> {
         if self.level > 1 {
             self.level -= 1;
-            self.add_indent();
+            self.add_indent()?;
-            self.output += "}\n";
+            self.write(b"}")?;
         }
         Ok(())
     }
 }
 
-impl<'a> serde::ser::SerializeStructVariant for &'a mut Serializer {
+impl<'a, W> serde::ser::SerializeStructVariant for &'a mut Serializer<W>
+where
+    W: std::io::Write,
+{
     type Ok = ();
     type Error = Error;
 
@@ -486,21 +532,18 @@ impl<'a> serde::ser::SerializeStructVariant for &'a mut Serializer {
     where
         T: Serialize,
     {
-        self.add_indent();
+        self.add_indent()?;
         key.serialize(&mut **self)?;
-        self.output += " = ";
+        self.write(b" = ")?;
         value.serialize(&mut **self)?;
-        if !self.output.ends_with('\n') {
+        self.write(b"\n")
-            self.output += "\n";
-        }
-        Ok(())
     }
 
     fn end(self) -> Result<Self::Ok> {
         if self.level > 0 {
             self.level -= 1;
-            self.add_indent();
+            self.add_indent()?;
-            self.output += "}\n";
+            self.write(b"}")?;
         }
         Ok(())
     }

tests/serialize.rs

@@ -81,17 +81,14 @@ fn serialize_non_representable_floats() {
     }
 
     let tests = [std::f64::NAN, std::f64::INFINITY, std::f64::NEG_INFINITY];
-    let expected = String::from("value = null\n");
     for value in tests {
         let value = Value64 { value };
-        let actual = to_string(&value).unwrap();
+        assert!(to_string(&value).is_err());
-        assert_eq!(actual, expected);
     }
     let tests = [std::f32::NAN, std::f32::INFINITY, std::f32::NEG_INFINITY];
     for value in tests {
         let value = Value32 { value };
-        let actual = to_string(&value).unwrap();
+        assert!(to_string(&value).is_err());
-        assert_eq!(actual, expected);
     }
 }