= The `JSON` structure
:Author: John Reppy
:Date: {release-date}
:stem: latexmath
:source-highlighter: pygments
:VERSION: {smlnj-version}

== Synopsis

[source,sml]
------------
structure JSON
------------

== Interface

[source,sml]
------------
datatype value
  = OBJECT of (string * value) list
  | ARRAY of value list
  | NULL
  | BOOL of bool
  | INT of IntInf.int
  | INTLIT of string
  | FLOAT of real
  | STRING of string
------------

== Description

`[.kw]#datatype# value = ...`::
  [[type:value]]
  This datatype represents *JSON* values as trees.  The constructors
  are
+
--
    `OBJECT [.kw]#of# (string * value) list`::
      represents a *JSON* object value; _i.e._, a list of key-value pairs.
      Note that the keys should be unique.

    `ARRAY [.kw]#of# value list`::
      represents a *JSON* array value.

    `NULL`::
      represents the *JSON* value `"null"`.

    `BOOL [.kw]#of# bool`::
      represents the *JSON* values `"true"` and `"false"`.

    `INT [.kw]#of# IntInf.int`::
      represents *JSON* integer numbers.

    `INTLIT [.kw]#of# string`::
      represents *JSON* integer numbers that have a large number of digits.

    `FLOAT [.kw]#of# real`::
      represents *JSON* floating-point numbers.

    `STRING [.kw]#of# string`::
      represents *JSON* strings, which are assumed to be UTF-8 encoded.
--

== Example

The *JSON* value

[source,json]
-------------
{ "a" : 23,
  "b" : [ false, true ],
  "c" : "hello world"
}
-------------

has the following representation using the *value* datatype:

[source,sml]
------------
OBJECT[
  ("a", INT 23),
  ("b", ARRAY[BOOL false, BOOL true]),
  ("c", STRING "hello world")
]
------------


== See Also

xref:../JSON/json-lib.adoc[__The JSON Library__]
