serde-query

Welcome to serde-query, a Rust library that lets you write jq-like queries for your data.

Why serde-query?

  1. Efficiency: With serde-query, you can efficiently extract exactly what you need without wasting the memory.
  2. Helpful error messages: When queries fail, you'll get clear, concise error messages that tell you where and why the failure happens.
  3. Flexibility: serde-query supports any serde-compatible data formats.

Getting started

To get started with serde-query, add it to your Rust project using Cargo:

bash cargo add serde-query

Or, add it to your Cargo.toml:

toml [dependencies] serde-query = "0.2.0"

Example

Array queries

```rust use serde_query::{DeserializeQuery, Query};

[derive(DeserializeQuery)]

struct Data { #[query(".commits.[].author")] authors: Vec, #[query(".count")] count: usize, }

let document = serdejson::json!({ "commits": [ { "author": "Kou", "hash": 0x0202 }, { "author": "Kasumi", "hash": 0x1013 }, { "author": "Masaru", "hash": 0x0809 }, ], "count": 3, }).tostring();

// You can use Query<T> as a Deserialize type for any Deserializer // and convert the result to the desired type using From/Into. let data: Data = serdejson::fromstr::>(&document)?.into();

asserteq!(data.authors, vec!["Kou", "Kasumi", "Masaru"]); asserteq!(data.count, 3); ```

Errors

```rust use serde_query::Deserialize;

[derive(Debug, Deserialize)]

struct Data { // missing field #[query(".author.name")] authorname: String, // typo #[query(".commit.commiter.name")] committername: String, // type error #[query(".author.id")] id: String, }

let error = serdejson::fromstr::(INPUT).unwraperr(); asserteq!( error.tostring(), r#" Queries failed for fields: 'authorname', 'committername', 'id' 1. Query for field 'authorname' failed at '.author': missing field 'name' 2. Query for field 'committername' failed at '.commit': missing field 'commiter' 3. Query for field 'id' failed at '.author.id': invalid type: integer 5635139, expected a string at line 34 column 17 "# .trimstart() ); ```

Note

This library generates Rust types for each query segment (e.g., .commit, .commit.message, etc.), which may lead to binary bloat and longer compile time.

License

Licensed under either of

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.