yamlt - YAML codec using Jsont type descriptions#

Yamlt provides YAML streaming encode/decode that interprets Jsont.t type descriptions, allowing the same codec definitions to work for both JSON and YAML.

Key Features#

• Use the same Jsont.t codec for both JSON and YAML formats
• Streaming encode/decode with configurable depth and node limits
• Support for YAML-specific features (scalars, sequences, mappings)
• Billion laughs protection with configurable limits
• Multiple output formats (block, flow, layout preservation)

Usage#

(* Define a codec once using Jsont *)
module Config = struct
  type t = { name: string; port: int }
  let make name port = { name; port }
  let jsont =
    Jsont.Object.map ~kind:"Config" make
    |> Jsont.Object.mem "name" Jsont.string ~enc:(fun c -> c.name)
    |> Jsont.Object.mem "port" Jsont.int ~enc:(fun c -> c.port)
    |> Jsont.Object.finish
end

(* Use the same codec for both JSON and YAML *)
let from_json = Jsont_bytesrw.decode_string Config.jsont json_str
let from_yaml = Yamlt.decode_string Config.jsont yaml_str

For encoding:

(* Encode to YAML with different formats *)
let config = Config.make "server" 8080

(* Block style (default) *)
let yaml_block = Yamlt.encode_string Config.jsont config

(* Flow style (JSON-like) *)
let yaml_flow = Yamlt.encode_string ~format:Flow Config.jsont config

Installation#

opam install yamlt

Documentation#

API documentation is available at https://tangled.org/@anil.recoil.org/ocaml-yamlt or via:

opam install yamlt
odig doc yamlt

License#

ISC