serde_hashkey/
lib.rs

Help
1//! [<img alt="github" src="https://img.shields.io/badge/github-udoprog/serde--hashkey-8da0cb?style=for-the-badge&logo=github" height="20">](https://github.com/udoprog/serde-hashkey)
2//! [<img alt="crates.io" src="https://img.shields.io/crates/v/serde-hashkey.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/serde-hashkey)
3//! [<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-serde--hashkey-66c2a5?style=for-the-badge&logoColor=white&logo=data:image/svg+xml;base64,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" height="20">](https://docs.rs/serde-hashkey)
4//! [<img alt="build status" src="https://img.shields.io/github/actions/workflow/status/udoprog/serde-hashkey/ci.yml?branch=main&style=for-the-badge" height="20">](https://github.com/udoprog/serde-hashkey/actions?query=branch%3Amain)
5//!
6//! Serde-based in-memory key serialization which supports hashing.
7//!
8//! This allows any serde-serializable type to be converted into a value which
9//! implements `PartialEq`, `Eq`, `ParialOrd`, `Ord`, and `Hash`.
10//!
11//! [Key] is useful because it allows for a form of type-erasure. Let's say you
12//! want to build a generic in-memory key-value store where you want to store
13//! arbitrary serde-serializable keys. This is useful for things like caches or
14//! dependency injection frameworks.
15//!
16//! <br>
17//!
18//! ## Usage
19//!
20//! Add the following to your Cargo.toml:
21//!
22//! ```toml
23//! [dependencies]
24//! serde-hashkey = "0.4.5"
25//! ```
26//!
27//! <br>
28//!
29//! ## Float policies
30//!
31//! By default, [Key] can't include floating point types such as `f32` and
32//! `f64`. Neither of these are [totally ordered nor hashable].
33//!
34//! To enable the [Key] type to use `f32` and `f64` it can be constructed with a
35//! specific float policy.
36//!
37//! Available float policies are:
38//! * [RejectFloatPolicy] - the default behavior when using [to_key].
39//! * [OrderedFloat] - the behavior when using [to_key_with_ordered_float]. The
40//!   `ordered-float` feature must be enabled to use this. The behavior is
41//!   derived from the [`ordered-float` crate].
42//!
43//! <br>
44//!
45//! ## Features
46//!
47//! * `ordered-float` - Enables serializing floating point numbers through
48//!   behavior derived from the [`ordered-float` crate]
49//!
50//! <br>
51//!
52//! ## Examples
53//!
54//! > You can run this example with `cargo run --example book`
55//!
56//! ```
57//! use std::collections::HashMap;
58//!
59//! use serde_derive::{Deserialize, Serialize};
60//! use serde_hashkey::{from_key, to_key, Error, Key};
61//!
62//! #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
63//! struct Author {
64//!     name: String,
65//!     age: u32,
66//! }
67//!
68//! #[derive(Debug, PartialEq, Eq, Serialize, Deserialize)]
69//! struct Book {
70//!     title: String,
71//!     author: Author,
72//! }
73//!
74//! let book = Book {
75//!     title: String::from("Birds of a feather"),
76//!     author: Author {
77//!         name: String::from("Noah"),
78//!         age: 42,
79//!     },
80//! };
81//!
82//! let key = to_key(&book)?;
83//!
84//! let mut ratings = HashMap::new();
85//! ratings.insert(key.clone(), 5);
86//!
87//! println!("ratings: {:?}", ratings);
88//!
89//! println!(
90//!     "book as json (through key): {}",
91//!     serde_json::to_string_pretty(&key)?
92//! );
93//!
94//! println!(
95//!     "book as json (through original object): {}",
96//!     serde_json::to_string_pretty(&book)?
97//! );
98//!
99//! # Ok::<_, Box<dyn std::error::Error>>(())
100//! ```
101//!
102//! [totally ordered nor hashable]: https://internals.rust-lang.org/t/f32-f64-should-implement-hash/5436
103//! [Key]: https://docs.rs/serde-hashkey/latest/serde_hashkey/enum.Key.html
104//! [to_key]: https://docs.rs/serde-hashkey/latest/serde_hashkey/fn.to_key.html
105//! [RejectFloatPolicy]: https://docs.rs/serde-hashkey/latest/serde_hashkey/struct.RejectFloatPolicy.html
106//! [OrderedFloat]: https://docs.rs/serde-hashkey/latest/serde_hashkey/struct.OrderedFloat.html
107//! [to_key_with_ordered_float]: https://docs.rs/serde-hashkey/latest/serde_hashkey/fn.to_key_with_ordered_float.html
108//! [`ordered-float` crate]: https://docs.rs/ordered-float/2/ordered_float/
109
110#![deny(missing_docs)]
111#![cfg_attr(docsrs, feature(doc_cfg))]
112
113macro_rules! cfg_ordered_float {
114    ($($item:item)*) => {
115        $(
116            #[cfg(feature = "ordered-float")]
117            #[cfg_attr(docsrs, doc(cfg(feature = "ordered-float")))]
118            $item
119        )*
120    }
121}
122
123mod de;
124mod error;
125mod float;
126mod key;
127mod ser;
128
129#[doc(inline)]
130pub use crate::de::from_key;
131#[doc(inline)]
132pub use crate::error::{Error, Result};
133
134cfg_ordered_float! {
135    pub use crate::float::{to_key_with_ordered_float, OrderedFloat, OrderedFloatPolicy};
136}
137
138pub use crate::float::{FloatPolicy, FloatRepr, NeverFloat, RejectFloatPolicy};
139
140#[doc(inline)]
141pub use crate::key::{Float, Integer, Key};
142#[doc(inline)]
143pub use crate::ser::to_key;
serde_hashkey/lib.rs

serde_hashkey/
lib.rs
