hcl-rs

This repository contains the following rust crates around the Hashicorp Configuration Language (HCL):

• hcl-rs: HCL library with serde and expression evaluation support.
• hcl-edit: Parse and modify HCL documents while preserving whitespace and comments.
• hcl-primitives: Primitives used by the HCL sub-languages.

Feature parity with the go-hcl implementation

The crates in this repository try to closely follow these specifications that are part of the Hashicorp's HCL Go implementation:

• HCL Syntax-Agnostic Information Model
• HCL Native Syntax Specification
• HCL JSON Syntax Specification

At the parser level it should support all features that go-hcl does today. However, the implementations for formatting and expression evaluation in hcl-rs are relatively basic at the moment. There are plans to move formatting and expression evaluation capabilities into hcl-edit (which is used by hcl-rs under the hood and also contains the parser implementation) and to make them more powerful.

Another thing that is not included (yet), is the support for HCL schemas in order to validate that a parsed HCL document only contains an allowed set of blocks with expected attributes (e.g. to enable validation that a given terraform configuration only contains well-formed resource and data blocks etc.).

Additionally, schema support can help to make it easier to encode more complex configurations using custom types. These configurations are currently cumbersome to assemble because of limitations of the serde model.

Contributing

Contributions are welcome! Please read CONTRIBUTING.md before creating a PR.

License

If not stated otherwise, the source code inside this repository is licensed under either of Apache License, Version 2.0 or MIT license at your option.