perf: Allow writing json without serde

crates/json-write/CHANGELOG.md

@@ -0,0 +1,13 @@
+# Changelog
+
+The format is based on [Keep a Changelog].
+
+[Keep a Changelog]: http://keepachangelog.com/en/1.0.0/
+
+<!-- next-header -->
+## [Unreleased] - ReleaseDate
+
+Initial release
+
+<!-- next-url -->
+[Unreleased]: https://github.com/toml-rs/toml/compare/06332279463f17447e1218c834078535b5ed9ebd...HEAD

crates/json-write/Cargo.toml

@@ -0,0 +1,42 @@
+[package]
+name = "json-write"
+version = "0.0.1"
+description = """
+A low-level interface for writing out JSON
+"""
+categories = ["encoding"]
+keywords = ["encoding", "json", "no_std"]
+repository.workspace = true
+license.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+include.workspace = true
+
+[package.metadata.docs.rs]
+all-features = true
+rustdoc-args = ["--cfg", "docsrs", "--generate-link-to-definition"]
+
+[package.metadata.release]
+pre-release-replacements = [
+  {file="CHANGELOG.md", search="Unreleased", replace="{{version}}", min=1},
+  {file="CHANGELOG.md", search="\\.\\.\\.HEAD", replace="...{{tag_name}}", exactly=1},
+  {file="CHANGELOG.md", search="ReleaseDate", replace="{{date}}", min=1},
+  {file="CHANGELOG.md", search="<!-- next-header -->", replace="<!-- next-header -->\n## [Unreleased] - ReleaseDate\n", exactly=1},
+  {file="CHANGELOG.md", search="<!-- next-url -->", replace="<!-- next-url -->\n[Unreleased]: https://github.com/assert-rs/libtest2/compare/{{tag_name}}...HEAD", exactly=1},
+]
+
+[features]
+default = ["std"]
+std = ["alloc"]
+alloc = []
+
+[dependencies]
+
+[dev-dependencies]
+proptest = "1.6.0"
+serde = { version = "1.0.160", features = ["derive"] }
+serde_json = { version = "1.0.96" }
+snapbox = "0.6.0"
+
+[lints]
+workspace = true

crates/json-write/LICENSE-APACHE

@@ -0,0 +1 @@
+../../LICENSE-APACHE

crates/json-write/LICENSE-MIT

@@ -0,0 +1 @@
+../../LICENSE-MIT

crates/json-write/README.md

@@ -0,0 +1,22 @@
+# toml_writer
+
+[![Latest Version](https://img.shields.io/crates/v/toml.svg)](https://crates.io/crates/toml)
+[![Documentation](https://docs.rs/toml/badge.svg)](https://docs.rs/toml)
+
+A low-level interface for writing out TOML
+
+## License
+
+Licensed under either of
+
+* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or <http://www.apache.org/licenses/LICENSE-2.0>)
+* MIT license ([LICENSE-MIT](LICENSE-MIT) or <http://opensource.org/licenses/MIT>)
+
+at your option.
+
+### Contribution
+
+Unless you explicitly state otherwise, any contribution intentionally
+submitted for inclusion in the work by you, as defined in the Apache-2.0
+license, shall be dual-licensed as above, without any additional terms or
+conditions.

crates/json-write/src/key.rs

@@ -0,0 +1,53 @@
+#[cfg(feature = "alloc")]
+use alloc::borrow::Cow;
+#[cfg(feature = "alloc")]
+use alloc::string::String;
+
+use crate::JsonWrite;
+
+#[cfg(feature = "alloc")]
+pub trait ToJsonKey {
+    fn to_json_key(&self) -> String;
+}
+
+#[cfg(feature = "alloc")]
+impl<T> ToJsonKey for T
+where
+    T: WriteJsonKey + ?Sized,
+{
+    fn to_json_key(&self) -> String {
+        let mut result = String::new();
+        let _ = self.write_json_key(&mut result);
+        result
+    }
+}
+
+pub trait WriteJsonKey {
+    fn write_json_key<W: JsonWrite + ?Sized>(&self, writer: &mut W) -> core::fmt::Result;
+}
+
+impl WriteJsonKey for str {
+    fn write_json_key<W: JsonWrite + ?Sized>(&self, writer: &mut W) -> core::fmt::Result {
+        crate::value::write_json_str(self, writer)
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl WriteJsonKey for String {
+    fn write_json_key<W: JsonWrite + ?Sized>(&self, writer: &mut W) -> core::fmt::Result {
+        self.as_str().write_json_key(writer)
+    }
+}
+
+#[cfg(feature = "alloc")]
+impl WriteJsonKey for Cow<'_, str> {
+    fn write_json_key<W: JsonWrite + ?Sized>(&self, writer: &mut W) -> core::fmt::Result {
+        self.as_ref().write_json_key(writer)
+    }
+}
+
+impl<V: WriteJsonKey + ?Sized> WriteJsonKey for &V {
+    fn write_json_key<W: JsonWrite + ?Sized>(&self, writer: &mut W) -> core::fmt::Result {
+        (*self).write_json_key(writer)
+    }
+}

crates/json-write/src/lib.rs

@@ -0,0 +1,56 @@
+//! A low-level interface for writing out JSON
+//!
+//! # Example
+//!
+//! ```rust
+//! use json_write::JsonWrite as _;
+//!
+//! # fn main() -> std::fmt::Result {
+//! let mut output = String::new();
+//! output.open_object()?;
+//! output.newline()?;
+//!
+//! output.space()?;
+//! output.space()?;
+//! output.key("key")?;
+//! output.keyval_sep()?;
+//! output.space()?;
+//! output.value("value")?;
+//! output.newline()?;
+//!
+//! output.close_object()?;
+//! output.newline()?;
+//!
+//! assert_eq!(output, r#"{
+//!   "key": "value"
+//! }
+//! "#);
+//! #   Ok(())
+//! # }
+//! ```
+
+#![cfg_attr(all(not(feature = "std"), not(test)), no_std)]
+#![cfg_attr(docsrs, feature(doc_auto_cfg))]
+#![warn(clippy::std_instead_of_core)]
+#![warn(clippy::std_instead_of_alloc)]
+#![warn(clippy::print_stderr)]
+#![warn(clippy::print_stdout)]
+
+#[cfg(feature = "alloc")]
+extern crate alloc;
+
+mod key;
+mod value;
+mod write;
+
+#[cfg(feature = "alloc")]
+pub use key::ToJsonKey;
+pub use key::WriteJsonKey;
+#[cfg(feature = "alloc")]
+pub use value::ToJsonValue;
+pub use value::WriteJsonValue;
+pub use write::JsonWrite;
+
+#[doc = include_str!("../README.md")]
+#[cfg(doctest)]
+pub struct ReadmeDoctests;