strict-yaml-rust

A StrictYAML implementation for Rust obtained by savagely chopping off code from yaml-rust.

This crate was originally started as feature-gated (#[cfg(feature)]) fork of the original.

Making it standalone allows to use both implementations (full and strict) from the same app, with confidence that the documents expected to be StrictYAML compliant will not be parsed as full YAML by mistake.

Mad props going to the original crate author, Chen Yuheng.

What is StrictYAML?

StrictYAML is a subset of the YAML format, removing troublesome parts of the specification:

• No typing. StrictYAML only knows Strings, Arrays and Dicts (Maps)
• No duplicate keys
• No tags
• No anchors or refs
• No "flow" style (embedded JSON)

In short, keeping only the parts of YAML that we all know and love.

For more details, see the original documentation and implementation:

• http://hitchdev.com/strictyaml/
• https://github.com/crdoconnor/strictyaml

Caveats

Missing from this implementation is a programmatic schema, which would enable document validation and typed value parsing. Seems that you'll still have to parse integers and dates from strings, or send a PR!

Quick Start

Add the following to the Cargo.toml of your project:

toml [dependencies] strict-yaml-rust = "0.1"

or

toml [dependencies.yaml-rust] git = "https://github.com/fralalonde/strict-yaml-rust.git"

and import:

rust extern crate yaml_rust;

Use yaml::StrictYamlLoader to load the YAML documents and access it as Vec/HashMap:

```rust extern crate strictyamlrust; use strictyamlrust::{StrictYamlLoader, StrictYamlEmitter};

fn main() { let s = " foo: - list1 - list2 bar: - 1 - 2.0 "; let docs = StrictYamlLoader::loadfromstr(s).unwrap();

// Multi document support, doc is a yaml::Yaml
let doc = &docs[0];

// Debug support
println!("{:?}", doc);

// Index access for map & array
assert_eq!(doc["foo"][0].as_str().unwrap(), "list1");
assert_eq!(doc["bar"][1].as_str().unwrap(), "2.0");

// Chained key/array access is checked and won't panic,
// return BadValue if they are not exist.
assert!(doc["INVALID_KEY"][100].is_badvalue());

// Dump the YAML object
let mut out_str = String::new();
{
    let mut emitter = StrictYamlEmitter::new(&mut out_str);
    emitter.dump(doc).unwrap(); // dump the YAML object to a String
}
println!("{}", out_str);

} ```

Note that yaml_rust::Yaml implements Index<&'a str> & Index<usize>:

• Index<usize> assumes the container is an Array
• Index<&'a str> assumes the container is a string to value Map
• otherwise, Yaml::BadValue is returned

If your document does not conform to this convention (e.g. map with complex type key), you can use the Yaml::as_XXX family API to access your documents.

Features

• Pure Rust
• Ruby-like Array/Hash access API
• Low-level YAML events emission

Specification Compliance

This implementation aims to provide StrictYAML parser fully compatible with the StrictYAML specification.

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Fork & PR on Github.

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.