Module `Ezjsonm`Source

An easy interface on top of the Jsonm library.

This version provides more convenient (but far less flexible) input and output functions that go to and from string values. This avoids the need to write signal code, which is useful for quick scripts that manipulate JSON.

More advanced users should go straight to the Jsonm library and use it directly, rather than be saddled with the Ezjsonm interface below.

Basic types

Sourcetype value = [

| `Null
| `Bool of bool
| `Float of float
| `String of string
| `A of value list
| `O of (string * value) list

]

JSON fragments.

Sourcetype t = [

| `A of value list
| `O of (string * value) list

]

Well-formed JSON documents.

Sourceval value : t -> value

Cast a JSON well-formed document into a JSON fragment.

Sourceval wrap : value -> [> t ]

wrap v wraps the value v into a JSON array. To use when it is not possible to statically know that v is a value JSON value.

Sourceval unwrap : t -> value

unwrap t is the reverse of wrap. It expects t to be a singleton JSON object and it return the unique element.

Sourceval from_channel : in_channel -> [> t ]

Reading JSON documents and values

Read a JSON document from an input channel.

Sourceval from_string : string -> [> t ]

Read a JSON document from a string.

Sourceval value_from_channel : in_channel -> value

Read a JSON value from an input channel.

Sourceval value_from_string : string -> value

Read a JSON value from a string.

Sourceval value_from_src : Jsonm.src -> value

Low-level function to read directly from a Jsonm source.

Reading JSON documents and values -- with proper errors

Sourcetype error_location = (int * int) * (int * int)

Error locations in a source document follow the Jsonm representation of pairs of pairs ((start_line, start_col), (end_line, end_col)) with 0-indexed lines and 1-indexed columns.

Sourcetype read_value_error = [

| `Error of error_location * Jsonm.error
| `Unexpected of [ `Lexeme of error_location * Jsonm.lexeme * string | `End_of_input ]

]

Sourcetype read_error = [

| read_value_error
| `Not_a_t of value

]

Sourceval read_error_description : [< read_error ] -> string

A human-readable description of an error -- without using the error location.

Sourceval read_error_location : [< read_error ] -> error_location option

If the error is attached to a specific location in the buffer, return this location.

Sourceval from_channel_result : in_channel -> ([> t ], [> read_error ]) result

See from_channel.

Sourceval from_string_result : string -> ([> t ], [> read_error ]) result

See from_string.

Source

val value_from_channel_result : 
  in_channel ->
  (value, [> read_value_error ]) result

See value_from_channel.

Sourceval value_from_string_result : string -> (value, [> read_value_error ]) result

See value_from_string.

Sourceval value_from_src_result : Jsonm.src -> (value, [> read_value_error ]) result

See value_from_src.

Writing JSON documents and values

Sourceval to_channel : ?minify:bool -> out_channel -> t -> unit

Write a JSON document to an output channel.

Sourceval to_buffer : ?minify:bool -> Buffer.t -> t -> unit

Write a JSON document to a buffer.

Sourceval to_string : ?minify:bool -> t -> string

Write a JSON document to a string. This goes via an intermediate buffer and so may be slow on large documents.

Sourceval value_to_channel : ?minify:bool -> out_channel -> value -> unit

Write a JSON value to an output channel.

Sourceval value_to_buffer : ?minify:bool -> Buffer.t -> value -> unit

Write a JSON value to a buffer.

Sourceval value_to_string : ?minify:bool -> value -> string

Write a JSON value to a string. This goes via an intermediate buffer and so may be slow on large documents.

Sourceval value_to_dst : ?minify:bool -> Jsonm.dst -> value -> unit

Low-level function to write directly to a Jsonm destination.

Constructors

Sourceval unit : unit -> value

Same as `Null.

Sourceval bool : bool -> value

Same as `Bool b.

Sourceval string : string -> value

Same as `String s.

Sourceval strings : string list -> [> t ]

Same as `A [`String s1; ..; `String sn].

Sourceval int : int -> value

Same as `Float (float_of_int i).

Sourceval int32 : int32 -> value

Same as `Float (Int32.to_float i)

Sourceval int64 : int64 -> value

Same as `Float (Int64.to_float i)

Sourceval float : float -> value

Some as `Float f.

Sourceval list : ('a -> value) -> 'a list -> [> t ]

Build a list of values.

Sourceval option : ('a -> value) -> 'a option -> value

Either `Null or a JSON value.

Sourceval dict : (string * value) list -> [> t ]

Build a dictionnary.

Sourceval pair : ('a -> value) -> ('b -> value) -> ('a * 'b) -> [> t ]

Build a pair.

Source

val triple : 
  ('a -> value) ->
  ('b -> value) ->
  ('c -> value) ->
  ('a * 'b * 'c) ->
  [> t ]

Build a triple.

Accessors

Sourceexception Parse_error of value * string

All the following accessor functions expect the provided JSON document to be of a certain kind. In case this is not the case, Parse_error is raised.

Sourceval get_unit : value -> unit

Check that the JSON document is `Null.

Sourceval get_bool : value -> bool

Extract b from `Bool b.

Sourceval get_string : value -> string

Extract s from `String s.

Sourceval get_strings : value -> string list

Extract s1;..;sn from `A [`String s1; ...; `String sn].

Sourceval get_int : value -> int

Extract an integer.

Sourceval get_int32 : value -> int32

Extract a 32-bits integer.

Sourceval get_int64 : value -> int64

Extract a 64-bits integer.

Sourceval get_float : value -> float

Extract a float.

Sourceval get_list : (value -> 'a) -> value -> 'a list

Extract elements from a JSON array.

Sourceval get_option : (value -> 'a) -> value -> 'a option

Extract an optional document.

Sourceval get_dict : value -> (string * value) list

Extract the elements from a dictionnary document.

Sourceval get_pair : (value -> 'a) -> (value -> 'b) -> value -> 'a * 'b

Extract the pair.

Source

val get_triple : 
  (value -> 'a) ->
  (value -> 'b) ->
  (value -> 'c) ->
  value ->
  'a * 'b * 'c

Extract the triple.

High-level functions

Sourceval mem : value -> string list -> bool

mem v path is true if the given path is valid for the JSON document v.

Sourceval find : value -> string list -> value

Find the sub-document addressed by the given path. Raise Not_found if the path is invalid.

Sourceval find_opt : value -> string list -> value option

Find the sub-document addressed by the given path. Returns None if the path is invalid.

Sourceval update : value -> string list -> value option -> value

Update the sub-document addressed by the given path. If the provided value is None, then removes the sub-document.

Sourceval map : (value -> value option) -> value -> string list -> value

Apply a given function to a subdocument.

Sourceval encode_string : string -> value

Convert a (possibly non-valid UTF8) string to a JSON object.

Sourceval decode_string : value -> string option

Convert a JSON object to a (possibly non-valid UTF8) string. Return None if the JSON object is not a valid string.

Sourceval decode_string_exn : value -> string

Convert a JSON object to a (possibly non-valid UTF8) string.

Sourceval to_sexp : value -> Sexplib0.Sexp.t

Convert a JSON fragment to an S-expression.

Sourceval sexp_of_value : value -> Sexplib0.Sexp.t

An alias of to_sexp

Sourceval sexp_of_t : t -> Sexplib0.Sexp.t

Convert a JSON object to an S-expression

Sourceval of_sexp : Sexplib0.Sexp.t -> value

Convert an S-expression to a JSON fragment

Sourceval value_of_sexp : Sexplib0.Sexp.t -> value

AN alias of of_sexp

Sourceval t_of_sexp : Sexplib0.Sexp.t -> t

Convert an S-expression to a JSON object

Error handling

Sourceval parse_error : value -> ('a, unit, string, 'b) format4 -> 'a

Raise Parse_error

package ezjsonm

Module EzjsonmSource

Basic types

Reading JSON documents and values -- with proper errors

Writing JSON documents and values

Constructors

Accessors

High-level functions

Error handling

Module `Ezjsonm`Source