Module Yojson

module Yojson: sig .. end

The Yojson library provides runtime functions for reading and writing JSON data from OCaml. It addresses a few shortcomings of its predecessor json-wheel and is about twice as fast (2.7x reading, 1.3x writing; results may vary). The design goals of Yojson are the following:

Reducing inter-package dependencies by the use of polymorphic variants for the JSON tree type.
Allowing type-aware serializers/deserializers to read and write directly without going through a generic JSON tree, for efficiency purposes. Readers and writers of all JSON syntaxic elements are provided but are undocumented and meant to be used by generated OCaml code.
Distinguishing between ints and floats.
Providing optional extensions of the JSON syntax. These extensions include comments, arbitrary strings, optional quotes around field names, tuples and variants.

Author(s): Martin Jambon
See also JSON specification

Shared types and functions

val version : string

exception Json_error of string

val json_error : string -> 'a

type lexer_state = {

`buf : Bi_outbuf.t;`	`(*`	Buffer used to accumulate substrings	`*)`
`mutable lnum : int;`	`(*`	Current line number (counting from 1)	`*)`
`mutable bol : int;`	`(*`	Absolute position of the first character of the current line (counting from 0)	`*)`
`mutable fname : string option;`	`(*`	Name referencing the input file in error messages	`*)`

}

module Lexer_state: sig .. end

val init_lexer : ?buf:Bi_outbuf.t -> ?fname:string -> ?lnum:int -> unit -> lexer_state

Create a fresh lexer_state record.

val write_null : Bi_outbuf.t -> unit -> unit

val write_bool : Bi_outbuf.t -> bool -> unit

val write_int : Bi_outbuf.t -> int -> unit

val write_float : Bi_outbuf.t -> float -> unit

val write_std_float : Bi_outbuf.t -> float -> unit

val write_float_fast : Bi_outbuf.t -> float -> unit

val write_std_float_fast : Bi_outbuf.t -> float -> unit

val write_float_prec : int -> Bi_outbuf.t -> float -> unit

val write_std_float_prec : int -> Bi_outbuf.t -> float -> unit

val write_string : Bi_outbuf.t -> string -> unit

val write_intlit : Bi_outbuf.t -> string -> unit

val write_floatlit : Bi_outbuf.t -> string -> unit

val write_stringlit : Bi_outbuf.t -> string -> unit

val write_assoc : Bi_outbuf.t -> (string * json) list -> unit

val write_list : Bi_outbuf.t -> json list -> unit

val write_tuple : Bi_outbuf.t -> json list -> unit

val write_std_tuple : Bi_outbuf.t -> json list -> unit

val write_variant : Bi_outbuf.t -> string -> json option -> unit

val write_std_variant : Bi_outbuf.t -> string -> json option -> unit

val write_json : Bi_outbuf.t -> json -> unit

val write_std_json : Bi_outbuf.t -> json -> unit

JSON pretty-printing

val pretty_format : ?std:bool -> json -> Easy_format.t

Convert into a pretty-printable tree. See to_string for the role of the optional std argument.
See also Easy-format

val pretty_to_string : ?std:bool -> json -> string

Pretty-print into a string. See to_string for the role of the optional std argument.

val pretty_to_channel : ?std:bool -> Pervasives.out_channel -> json -> unit

Pretty-print to a channel. See to_string for the role of the optional std argument.