Yojson: low-level JSON library for OCaml

This library is for manipulating the json AST directly. For mapping between OCaml types and json, we recommend atdgen.

Library documentation

Currently at https://ocaml-community.github.io/yojson/

Design goals

• reducing inter-package dependencies by the use of polymorphic variants for the JSON tree type

• allowing variants of the JSON tree type to be shipped by the library itself or to be easily created as extensions of the library

• allowing type-aware serializers/deserializers such as json-static to read and write directly without going through a JSON tree, for efficiency purposes. This requires making readers and writers of JSON atoms (int, string, etc.) to be exported and composable.

• providing a few non-standard, optional extensions of JSON. These extensions will include:

  • optional quotes around "simple" field/constructor names
  • a syntax for tuples (at least 2 elements): (x, y)
  • a syntax for variants (0 or 1 arg only): <Foo> <Bar:"abc">

Other choices already in json-wheel

• distinction between ints and floats (optional)

• Getting rid of the UTF-X encoding constraint that prevents from exchanging binary data:

  • encoding is ASCII except for the contents of string literals
  • string literals may represent arbitrary sequence of bytes
  • \uABCD escapes in string literals expand to UTF-8

Miscellaneous

• no dependency on ocamlnet for UTF-8