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Low-level JSON parsing and pretty-printing library for OCaml
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NathanReb Revert "Release 1.7.1"
This reverts commit 5c4627a.
Latest commit 6f8ed3f May 20, 2019

Yojson: low-level JSON library for OCaml

Build Status

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

Library documentation

Currently at

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


  • no dependency on ocamlnet for UTF-8
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