1.2.108 • Public • Published

    JSOX – JavaScript Object eXchange format.

    Build Status

    100% Compatible reader for JSON. JSOX.stringify cannot generate JSON compatible output; it would lose all the features anyway; use existing JSON.stringify() if required, all JSON(JSON3/JSON5/JSON6) is valid JSOX.

    JSOX adds Map, BigInt, Date, and TypeArray transport support, cyclic objects, and includes keywords (5)'Infinity', (5)'NaN', (6)'undefined'.

    JSOX adds optional processing of typed data. Type names can be applied to Objects, Arrays and Strings. Type names are defined and provided with to/from JSOX handlers by users of this library. The data, decoded as the object '{}', array '[]', or string '""' is passed to the fromJSOX handler, and the resulting value returned as the decoded object.

    Typed-objects may also be emitted as a class-defintition and then class-references. A class-defintition defines the fields in the object, and a class-reference would provide the values for each field respectively.

    A typed-object example: v{ x, y } { a : v{1,2} }, which decodes as { a : {x:1,y:2} }. It defines a template/class of object that has fields 'x', and 'y'. Then defines an object with a field A what is a object of type 'v', with values (1), and (2). This example does not gain any visible savings; savings comes when you have a lot of the same sort of record with the same field names repeated often.

    • adds macro/class support for object field names.
    • adds support for bigint numbers; indicated with an 'n' suffix.
    • adds support for Date parsing and stringification; ISO dates as used are a sub-type of Number.
    • adds support for circular references.
    • typed-strings, typed-arrays, and typed-objects, for user defined types and to and from JSOX methods. more
    • C style commants; // and /* */.
    • string continuations using \ at the end of the line removes the newline; Otherwise strings continue until the next quote.
    • ", ', ``, are all valid quote pairings, with no differnce in meaning, other than the quotes they contain.
    • adds optional underscores in numbers, allowing user formatting of log numbers.
    • fields are canonically ordered, so all objects that have the same field names will have their names in the same order. Keys in Map()s are not ordered.
    • trailing commas are allowed, and silently ignored; however empty comma pairs in arrays will generate empty elements; and (throw an error in objects?).
    • and of course o === JSOX.parse(JSON.stringify(o)) should always be exactly true.

    Example Encoding

    r = JSOX.stringify( o = { 
    	a: "simple object"
    	, b:3
    	, c:new Date()
    	, d:123n
    	, e:null
    	, f:undefined
    	, g:NaN
    	, h:Infinity
    	, i:-Infinity
    	, j:-0.302 
    	, k:new Uint8Array(9)}, null, 3 );
    cnsole.log( "pretty:", o, "=\n", r );
    // -- output --
          a: "simple object",
          b: 3,
          c: 2018-09-14T02:55:27-07:00,
          d: 123n,
          e: null,
          g: NaN,
          h: Infinity,
          i: -Infinity,
          j: -0.302,
          k: u8[AAAAAAAAAAA=]

    JSOX is a proposed replacement to JSON that aims to make it easier for humans to write and maintain by hand, while also transporting the correct type of the data. Humans, for example, wouldn't hand-code a base64 encoding for a TypedArray; however sending a mesh from a server to a client already processed as a typed buffer ready for WebGL consumption may be of use.

    The class/tag support is entirely optional, and while it's goal is to reduce redundancy, which for large datasets of similar records can benefit, it has been argued that gzip could just be used to reduce the size; However, this also reduces the size of the data to be parsed on input, which gzip does not do.

    JSOX is a (super-sub)set of JavaScript, although adds no new data types, and works with all existing JSON content. Some features allowed in JSOX are not directly supported by Javascript; although all javascript parsable features can be used in JSOX, except functions or any other code construct, transporting only data save as JSON. Most ES6 structure can be parsed, with the extension of classes/macro-tags the reverse is not true. It was true for JSON6.

    JSOX is a proprosal for an official successor to JSON, and JSOX stringified content will not work with existing JSON parsers. For this reason, JSOX files use a new .jsox extension. (TODO: new MIME type needed too.)

    The code is a reference JavaScript implementation for both Node.js and all browsers. The code is derrived from JSON-6 sources.


    Beyond the existing reasons for JSON5/JSON6 for their modifications; this addresses the biggest shortcoming of JSON, which is the repetitive and redundant specification of field names; especially when lots of the same sort of object is represented.

    This also aims to provide support for BigInt and Date format for less work at the application layer. A method for handling typed array object members should also be impelemented

    (Historic Why below)

    JSON isn’t the friendliest to write. Keys need to be quoted, objects and arrays can’t have trailing commas, and comments aren’t allowed — even though none of these are the case with regular JavaScript today.

    That was fine when JSON’s goal was to be a great data format, but JSON’s usage has expanded beyond machines. JSON is now used for writing configs, manifests, even tests — all by humans.

    There are other formats that are human-friendlier, like YAML, but changing from JSON to a completely different format is undesirable in many cases. JSON6’s aim is to remain close to JSON and JavaScript.


    The following is the exact list of additions to JSON’s syntax introduced by JSOX. All of these are optional.

    • Concise representation of dates and times including as much information as is available for the timestamp(timezone).

    • Supports encode and decode of BigInt numbers with no application overhead.

    • reduces overhead from none-requires quotes for identifiers.

    • can further reduce overall output size by using macro tags.


    JSOX.stringify will produce output that JSON.parse cannot handle; JSOX.parse can always handle JSON.stringify.

    Summary of Changes from JSON6

    • BigInt encoding
    • ISO date/time Encoding/decoding (as part of Number format)
    • Adds classes(revive user types) and macro tags to reduce redundant information.

    Summary of Changes from JSON6/JSON

    • Keyword undefined
    • Objects/Strings back-tick quoted strings (no template support, just quotes); Object key names can be unquoted.
    • Strings - generous multiline string definition; all javascript character escapes work. (\x##, \0###, \u####, \u{} )
    • Numbers - underscore digit separation in numbers, octal and binary formats; all javascript number notations. Addtionally support leading 0 to interpret as octal as C, C++ and other languages support.
    • Arrays - empty members
    • Streaming reader interface
    • (Twice the speed of JSON5; subjective)
    • interprets non-breaking space as a space.

    Additional support above JSON base

    All items listed below are JSON5 additions if not specifed as JSON6.


    • (JSOX) Support transporting ArrayBuffer and TypedArray fields. This is implemented with constants as class user types applied prefixing and opening brace '[' and encoding the binary data as a base64 string(without quotes) before the closing ']'.
      • these are prefix tags that can be applied. u8, u16, cu8, u32, s8,s16, s32, f32, f64, ab; the array is a base64 string without quotes.
      • Base64 is as dense as is feasible; it's a 33% loss; where utf8 encoding of random bytes is 50% loss. Something like base127 would be 7 bytes to 8 encoded bytes; and potential length penalty of 5 bytes.


    • Object keys can be unquoted if they do not have ':', ']', '[', '{', '}', ',', any quote or whitespace (including non-breaking space, which on the human side of things looks the same), and do not begin like a number.

    • Object keys can be single-quoted, (JSON6) or back-tick quoted; any valid string

    • Object keys can be double-quoted (original JSON).

    • Objects can have a single trailing comma. Excessive commas in objects will cause an exception. '{ a:123,,b:456 }' is invalid.


    • Arrays can have trailing commas. If more than 1 is found, additional empty elements will be added.

    • (JSON6) Arrays can have comma ( ['test',,,'one'] ), which will result with empty values in the empty places.


    • Strings can be double-quoted (as per original JSON).

    • Strings can be single-quoted.

    • Strings can be back-tick (`) (grave accent) -quoted.

    • Strings can be split across multiple lines; just prefix each newline with a backslash. [ES5 §7.8.4]

    • (JSON6) all strings will continue keeping every character between the start and end, this allows multi-line strings and keep the newlines in the string; if you do not want the newlines they can be escaped as previously mentioned.


    • (JSOX) BitInt numbers are stringified with suffix of 'n' as in ES(?), and implemented in V8(google/chrome/node) 2018/09/12. BigInt number parsed with 'n' suffix.

    • (JSON6) Numbers can have underscores separating digits '_' these are treated as zero-width-non-breaking-space. (Proposal with the exception that _ can preceed or follow . and may be trailing.)

    • Numbers can be hexadecimal (base 16). ( 0x prefix )

    • (JSON6) Numbers can be binary (base 2). (0b prefix)

    • (JSON6) Numbers can be octal (base 8). (0o prefix)

    • (JSON6) Decimal numbers can have leading zeros. (0 prefix followed by more numbers, without a decimal)

    • Numbers can begin or end with a (leading or trailing) decimal point.

    • Numbers can include Infinity, -Infinity, NaN.

    • Numbers can begin with an explicit plus sign.

    • Numbers can begin with multiple minus signs. For example '----123' === 123.


    • (JSOX) Encodes date time with local timestamp information to recover as much information as the original date contained. Is treated as a subtype of Number parsing; and are stored without quotes.

    Keyword Values

    • (JSON6) supports 'undefined' in addition to 'true', 'false', 'null'.


    • Both inline (single-line using '//' (todo:or '#'?) ) and block (multi-line using /* */ ) comments are allowed.
    • (JSOX) single line comments using '#'; imposes required quoting for '#' as a field name.
    // simple example, array buffer with 8 bytes
    var ab = new ArrayBuffer([0,1,2,3,4,5,6,7]);
    console.log( JSOX.stringify( {ab:new Float32Array(ab)} ) );
    // example output

    Base64 Character Set

    The following defines the characters used for base64 encoding and decoding.

    	const encodings = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789$_'
       // previous to 1.2.106
    	//const encodings = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
    	const decodings = { '~':-1

    The high value characters have multiple possible variations based on evaluation of what was used in wikipedia; forming the most inclusive subset. ~ or = may be used for string termination, or early string length.

    Base64 vs UTF-8 Encoding

    UTF-8, for character 0-127 requires 1 byte; 128-255 requires 2 bytes. For random data 0-255, 1.5 bytes will, on average, bt used to represent the string. So this is 150% larger than the original string. Even if like a base 2^40 bits, which would encode 5 bytes into a single (very extended) utf8 encoding, each byte has the prefix of 2 bits 10xx xxxx, which gives 6 bits per byte used.

    Base64 is 6 bits per byte used, so instead of having a complex encoder, base64 is the optimal of 3:4 byte expasion (133%) which is the ideal that extra-long UTF8 encoding coule reach.

    An alternative might be a base128 encoding, which would be close to utf-8, but would actually require 129 characters, one to indicate the bytes that are unused. 7 bytes expand to 8, gathering the top bit of each of the 7 bytes of each one into one more byte; it could be an optimal encoding using code points 0-128 (128 being the end terminator like '=' in base64). But, this also mean that up to 5 bytes of waste may be included. That is incomplete values at the end of the string have to be marked as unused.

    Pretty Images

    Image produced by EBNF Visualizer (Windows) from jsox.ebnf JSOX Value BNF JSOX Value BNF JSOX Parser BNF

    Example conversion

    The following is a contrived example, but it illustrates most of the features:

        foo: 'bar',
        while: true,
        nothing : undefined, // why not?
        this: 'is a \
    multi-line string',
        thisAlso: 'is a
    multi-line string; but keeps newline',
        // this is an inline comment
        here: 'is another', // inline comment
        /* this is a block comment
           that continues on another line */
        hex: 0xDEAD_beef,
        binary: 0b0110_1001,
        decimal: 123_456_789,
        octal: 0o123,
        decimal: 001234, // with lead 0
        half: .5,
        delta: +10,
        negative : ---123,
        to: Infinity,   // and beyond!
        ,,,,,,  // some empty fields...
        finally: 'a trailing comma',
        oh: [
            "we shouldn't forget",
            'arrays can have',
            'trailing commas too',

    This implementation’s own package.jsox is more realistic:

    // This file is written in JSOX syntax, naturally, but npm needs a regular
    // JSON file, so compile via `npm run build`. Be sure to keep both in sync!
        name: 'JSOX',
        version: '0.1.105',
        description: 'JSON for the ES6 era.',
        keywords: ['json', 'es6'],
        author: 'd3x0r <d3x0r@github.com>',
        contributors: [
            // TODO: Should we remove this section in favor of GitHub's list?
            // https://github.com/d3x0r/JSOX/contributors
        main: 'lib/JSOX.js',
        bin: 'lib/cli.js',
        files: ["lib/"],
        dependencies: {},
        devDependencies: {
            gulp: "^3.9.1",
            'gulp-jshint': "^2.0.0",
            jshint: "^2.9.1",
            'jshint-stylish': "^2.1.0",
            mocha: "^2.4.5"
        scripts: {
            build: 'node ./lib/cli.js -c package.JSOX',
            test: 'mocha --ui exports --reporter spec',
                // TODO: Would it be better to define these in a mocha.opts file?
        homepage: 'http://github.com/d3x0r/JSOX/',
        license: 'MIT',
        repository: {
            type: 'git',
            url: 'https://github.com/d3x0r/JSOX',


    Join the Google Group if you’re interested in JSOX news, updates, and general discussion. Don’t worry, it’s very low-traffic.

    The GitHub wiki (will be) a good place to track JSOX support and usage. Contribute freely there!

    GitHub Issues is the place to formally propose feature requests and report bugs. Questions and general feedback are better directed at the Google Group.


    This JavaScript implementation of JSOX simply provides a JSOX object just like the native ES5 JSON object.

    To use from Node:

    npm install jsox
    var JSOX = require('jsox');

    To use in the browser (adds the JSOX object to the global namespace):

    <script src="node_modules/jsonx/lib/jsox.js"></script>

    Then in both cases, you can simply replace native JSON calls with JSOX:

    var obj = JSOX.parse('{unquoted:"key",trailing:"comma",}');
    var str = JSOX.stringify(obj); /* uses JSON stringify, so don't have to replace */
    JSOX Methods return parameters Description
    parse the first value (string [,reviver]) supports all of the JSOX features listed above, as well as the native [reviver argument][json-parse].
    stringify string ( value[,replacer[,space]] ) converts object to JSOX. [stringify][json-stringify]
    stringifier Stringifier(methods below) () Gets a utility object that can stringify. The object can have classes defined on it for stringification
    escape string ( string ) substitutes ", , ', and ` with backslashed sequences. (prevent 'JSON injection')
    begin Parser(methods below) (cb [,reviver] ) create a JSOX stream processor. cb is called with (value) for each value decoded from input given with write(). Optional reviver is called with each object before being passed to callback.
    toJSOX none (name,Function/Class,toCb) For each object that matches the prototype, the name is used to prefix the type; and the cb is called to get toJSOX.
    fromJSOX none (name,Function/Class,fromCb) fromCb is called whenever the type 'name' is revived. The type of object following the name is passd as 'this'. Will throw an exception if duplicate set happens.
    registerToFrom none (name,Function/Class,toCb, fromCb) register both to and from for the same name
    Stringifier method return parameters Description
    stringify string (value[,replacer[,space]] ) converts object to JSOX attempting to match objects to classes defined in stringifier. [stringify][json-stringify]
    toJSOX none (name,Function/Class,toCb) For each object that matches the prototype, the name is used to prefix the type; and the cb is called to get toJSOX.
    setQuote none ( quote ) the argument passed is used as the default quote for strings and identifiers as required.
    defineClass none ( name, object ) Defines a class using name 'name' and the fields in 'object'. This allows defining for some pre-existing object; it also uses the prototype to test (if not Object), otherwise it matches based on they Object.keys() array.
    Parser Methods parameters Description
    write (buffer) add data to the parser stream
    fromJSOX (name,Function/Class,fromCb) fromCb is called whenever the type 'name' is revived. The type of object following the name is passd as 'this'. Will throw an exception if duplicate set happens.

    Registering toJSOX : JSOX.toJSOX() or stringifier.toJSOX()

    function toJSOX( name, Type, customEmitterCallback )

    • name is a string
    • Type is the type which should be encoded as this name.
    • customEmitterCallback is called when one of these types is encountered. The callback should return a string to emit.

    toJSOX() registers a handler to convert a type to JSOX. This method is used to avoid modification of prototypes; would require instead that ojects that have a toJSOX know of the JSOX module instead. The result of the callback should be a string, and is up to the toJSOX method to include quotes if it is a string value. Any string may result that is valid JSOX.

    Regsitering the same name more than once throws an error.

    function stringTest() {
    	this.a = 3;
    	this.b = 4;
    stringifierTest.prototype.toString = function(stringifier) {
    	return `a is ${this.a} b is ${this.b}`;
    JSOX.toJSOX( "stringTest", stringTest, function(stringifier) { return '"' + this.toString() + '"' } );

    The callback specified is passed the current value to stringify as this, and the current stringifier is passed as the first argument. If the structure contains cyclic references, the provided stringifier is required to be used instead of JSOX.stringify() or a new instance of a stringifier when encoding the sub-members of this object; otherwise, the references do not properly refer to the root of the object.

    Registering fromJSOX : JSOX.fromJSOX() or parser.fromJSOX()

    fromJSOX( name, type, callback )

    • name is the tag text which triggers reviving this type.
    • type is the class or function used to create a new type(). The instance is always created with empty parameters.
    • callback(field,val) is called with this set to the object of the type specified, and field set as the current field name being revived, val is the value being set into the field. If field is undefined then this is the end of all fields being added to the object, and the this object may be changed to a different object; usually if( field === undefined ) return this;.

    Registers a handler to convert recovered string, array or object from JSOX. The converted data from the JSOX stream is passed as 'this'. The result of the callback may be any type of value; the resulting value is used instead of the data converted from JSOX.

    Regsitering the same name more than once throws an error.

    // this epects a string, as indicated by the above toJSOX output.
    function stringTest() {
    // if a field callback is specified, the function must either result with
    // undefined, which prevents setting the value internally, or return the same
    // or a new value for the value.
    // if the field is 'undefined' then must instead return 'this' or a new object 
    // to take the place of this one.
    stringTest.fromJSOX = function(field,val) {
    	if( field ) {
    		console.log( "Resuurect from String:[%s]", this /*string*/ );
    	} else
    		return new stringTest( this );
    JSOX.fromJSOX( "stringTest", stringTest, stringTest.fromJSOX );

    Register toJSOX and fromJSOX for the same type

    Registers both to and from methods or a spsecified name, using the specified prototype to match during stringify. Internally, calls the above functions with the parameters split as appropriate.

    Regsitering the same name more than once for From or To throws an error.

    JSOX.registerToFrom( "stringTest", stringTest
    	, function() { return '"' + this.toString() + '"' }
    	, function() {
    		console.log( "Resuurect from String:[%s]", this /*string*/ );
    		return new stringTest( this );  // some stringTest class with string initializer

    JSOX typed-objects, typed-arrays, and typed-strings

    typed-data is represented in the JSOX stream as <identifier>[data]. For objects, this is a document compression technique, which reduces the size of data to process. For arrays, internally, fixed types represent ES6 TypedArray types (u8,s8, u16,f32,etc); Another internal type is 'ref' which uses the array to have a list of element identifiers that define the path to the original object reference. Another, simple variation is to implement typed-strings, which allows color"0x1234568" to have a fromJSOX method that is passed the string, and can result with a color object.

    In each case, in the following example JSOX, the same 'color' fromJSOX method will be called. It will be invoked with a string, with an array, with an object, with an object, and with an object respectively.

    var JSOX= require( "JSOX" );
    function Color() {
    	this.r = 100;
            this.g = 150;
            this.b = 20;
    // notice that the literal quotes to result as output are returned here.
    // this allows the encoder to use an object {}, an array [] or a string ""
    // to pass to the reviver function. 
    sack.JSOX.registerToFrom( "color", Color.prototype, function() { return '"#'+this.r.toString(16)+this.g.toString(16)+this.b.toString(16)+ '"'; }
               , function() { return '"#'+this.r.toString(16)+this.g.toString(16)+this.b.toString(16)+ '"'; }
    var c = new Color();
    JSOX.stringify( c ) ); // result is 'color"#649614"'
    JSOX.parse( JSOX.stringify( c ) ); // result is   'Color { r: 100, g: 150, b: 20 }'  (console.log)
    // this are all variations which may be used to revive a color object
    color"0x12345678"                   // typed-string
    color[0x12,0x34,0x56,0x78]          // typed-array
    // at a root level, the first 'color' definition encountered
    // is used to create a field-name map.  Then later usages
    // sould only specify the values.
    color{r,g,b,a}            // typed-object definition
    color{0x12,34,0x56,0x78}  // typed-object subsequent usage
    // if no typed-object definition is rquired, then 
    // the typed-object must never be used at a root level.
    { a : color{r:0x12,g:0x34,b:0x56,a:0x78} } // object containing typed-object fromJSOX only, no pre-field-definition
    [ color{r:0x12,g:0x34,b:0x56,a:0x78} ]     // array containing typed-object fromJSOX only, no pre-field-definition

    Typed strings have a caveat; at a root level, strings which are typed, MUST have unquoted-identifier strings indicating their type. Because the closing quote is a definitive end-of-data marker, quoted strings at a root level always emit as a completed string; This also requires no space between the unquoted-identifier string and the quoted data string.

    Typed-object and typed-arrays also require the identifer or string used for their type information not be followed by a space before the opening '{', '[' or quoted string.

    More on Classes/Macro Tags - typed-object and typed-array

    Macro Tags are similar to class names, but define a set of field names to use for each subsequent use of the same number. The names used for class names and for Macro tags may overlap, and then the macro objects are also revived as specified user types. If only a Macro Tag is used, then all objects revived with that tag have the same prototype, which may be extended in-place for all such objects.

    The definition of a Macro Tag is an identifer at the top level (before the JSOX data) followed immediately by an open brace ('{'), whitespace is not allowed. Within the open brace '{' until the close brace '}' is a list of names separated by commas. If a colon(:) is encountered before the first comma(,) , then instead of behaving as a Macro definition, the object is revived as a named user type class instead.

    All subsequent references to the defined tag are <identifier> followed by '{' until the close '}', is a list of comma separated values.
    Each value is assign the name in the order it was defined at the definition. This is effectively a 'zip' operation between the names specfied at the start, and the values specified later.

    All objects created with a class/tag definition shares the same prototype.

    tagdef : identifier '{' identifier [ ',' identifier ] ... '}'

    A class revival is similar, but includes both the identifer and value for each entry.

    userType : identifier '{' identifier ':' value [ ',' identifier ':' value ] ... '}'

    Usage of tags is done by specifing their identifer followed by an open brace '{' in the value field of an object definition; or at a top level referencing the same tag name already defined. For each field defined in the class, a value is expected. If a value is not found, the field will not be added, as if receiving field:undefined.

    tag usage : ':' identifier '{' value [ ',' value ]... '}' 
    //-- the following...
    a{ firstField, secondField }
    a{ 1, 2 }
    //-- results as
    { firstField : 1, secondField : 2 }
    //-- the following...
    a { firstField, secondField }
    [ a { 1, 2 }, a(5,6), a("val1","val2") ]
    //-- results as
    [ { firstField : 1, secondField : 2 }, { firstField : 5, secondField : 6 }, { firstField : "val1", secondField : "val2" } ]

    Implementation of tags allows apply a class to arrays. Arrays have a class of ArrayBuffer, or other TypedArray type. The representation path in an array and a reference type for the array. This allows circular encoding.

    // this is a string with a reference.
    // The above 'ref[]' gets resolved into the same employee object...
    OUT: ./file6.jsox { company:
       { name: 'Example.com',
         employees: [ /*a*/{ name: 'bob' }, { name: 'tom' } ],
         manager: /*a*/{ name: 'bob' } } }

    JSOX Streaming

    A Parser that returns objects as they are encountered in a stream can be created. JSON.begin( dataCallback, reviver ); The callback is called for each complete object in a stream of data that is passed.

    JSOX.begin( cb, reviver ) returns an object with a few methods.

    Method Arguments Description
    write (string) Parse string passed and as objects are found, invoke the callback passed to begin() Objects are passed through optional reviver function passed to begin().
    _write (string,completeAtEnd) Low level routine used internally. This does the work of parsing the passed string. Returns 0 if no object completed, 1 if there is no more data, and an object was completd, returns 2 if there is more data and a parsed object is found. if completedAtEnd is true, dangling values are returned, for example "1234" isn't known to be completed, more of the number might follow in another buffer; if completeAtEnd is passed, this iwll return as number 1234. Passing empty arguments steps to the next buffered input value.
    value () Returns the currently completed object. Used to get the completed object after calling _write.
    reset () If write() or _write() throws an exception, no further objects will be parsed becuase internal status is false, this resets the internal status to allow continuing using the existing parser. ( May require some work to actually work for complex cases)
    usePrototype (className,protoType) configure what prototypes to use for class recovery
       // This is (basically) the internal loop that write() uses.
       var result
       for( result = this._write(msg,false); result > 0; result = this._write() ) {
          var obj = this.value();
          // call reviver with (obj)
          // call callback with (obj)
    // Example code using write
    function dataCallback( value ) {
    	console.log( "Value from stream:", value );
    var parser = JSON.begin( dataCallback );
    parser.write( '"Hello ' );   // a broken simple value string, results as 'Hello World!' 
    parser.write( 'World!"' );
    parser.write( '{ first: 1,' );   // a broken structure
    parser.write( ' second : 2 }' );
    parser.write( '[1234,12');  // a broken array across a value
    parser.write( '34,1234]'); 
    parser.write( '1234 456 789 123 523');  // multiple single simple values that are numbers
    parser.write( '{a:1} {b:2} {c:3}');  // multiple objects
    parser.write( '1234' );  // this won't return immediately, there might be more numeric data.
    parser.write( '' ); // flush any pending numbers; if an object or array or string was split, throws an error; missing close.
    parser.write( '1234' ); 
    parser.write( '5678 ' );  // at this point, the space will flush the number value '12345678' 


    If you’re running this on Node, you can also register a JSOX require() hook to let you require() .jsox files just like you can .json files:

    require('./path/to/foo');   // tries foo.jsox after foo.js, foo.json, etc.

    This module also provides a jsox executable (requires Node) for converting JSOX files to JSON:

    jsox -c path/to/foo.jsox    # generates path/to/foo.json

    Other Implementations

    This is also implemented as part of npm sack.vfs as a native code node.js addon. This native javascript version allows usage in browsers.

    C/C++ Amalgam version jsox-wasm

    Possible release of amagamated source, native Node Addon (standalone). (Amalagmanted source is for now in jsox-wasm repository).

    Working on a WebAssembly version. jsox-wasm The overhead of the string exchange between WASM and JS (strings, key names of objects), defeats any benefit from 0 garbage collected/managed parsing.


    This is as fast as the javascript version of Douglas Crockford's reference implementation [JSON implementation][json_parse.js] for JSON parsing.

    This is nearly double the speed of JSON5 implementation that inspired this (which is half the speed of Crockford's reference implementation).

    This is half the speed of the sack.vfs native C++ node addon implementation (which itself is half the speed of V8's native code implementation, but they can cheat and build strings directly).


    git clone https://github.com/d3x0r/jsox
    cd jsox
    npm install
    npm test

    As the package.jsox file states, be sure to run npm run build on changes to package.jsox, since npm requires package.json.

    Feel free to file issues and submit pull requests — contributions are welcome. If you do submit a pull request, please be sure to add or update the tests, and ensure that npm test continues to pass.

    Continuous Integration Testing

    Travis CI is used to automatically test the package when pushed to github. Recently .mjs tests have been added, and rather than build a switch to test mocha/test/*.js instead of just *, and depending on node version switch the test command which is run, the older platforms were removed from testing.

    The product of this should run on very old platforms also, especially node_modules/jsox/lib/jsox.min.js.


    • 1.2.108
      • Refix base64, which failed to quote strings that looked like numbers.
      • Clear array buffer typed variable when resolving the typed array; leaked to next parse.
    • 1.2.107
      • Updated document about CI tests.
      • Enable Travis CI integration.
      • Reference arrays don't result with the same object; reduce frequency of warning message.
      • Remove automatic guess promoting numbers to bigints, floats can also be pretty big.
    • 1.2.106
      • fix regression in stringifying binary array objects; removing the quotes caused the '/' to be interpreted as a comment.
      • update documentation about base64 encoding
      • replace '+/' with '$_' as the high value strings emitted. Older versions will already accept this encoding.
    • 1.2.105
      • Fix losing array containing typed objects.
      • Pass stringifier to toJSOX method.
      • Added compatibility tests between sack.vfs node plugin and JS version.
      • Fixed issues reviving references (new test), and replacing/providing values.
    • 1.2.104
      • Throw error while parser is in error state and new writes() are called.
      • allow '+' prefix to numbers
      • Fix fromJSOX class revival handling; call per-field.
      • Added beginning of stringify tests (coverage).
    • 1.2.103
      • additional reference path revival fix.
    • 1.2.102
      • added automated test notes
      • Added formal reference revival test; a different recursive variation of reference which failed.
      • refactored to remove 'element_array' special case tracking variable; standardize on just 'elements' instead.
    • 1.1.123 (published as 1.2.101)
      • Added automated mocha tests; (ported from JSON6).
      • Fixed some parsing issues exposed by tests around unicode whitespace handling and more.
      • Throw an error when a invalid date is created.
      • Most fixes were in handling badly formatted data either with exceptions, or accepting more badly formatted input as valid.
    • 1.1.122
      • Remove option SUPPORT_LEAD_ZERO_OCTAL; JS "strict" errors on lead zeros; and Number() converts lead zeros as decimal; removes custom decoding.
    • 1.1.121
      • fix parsing {op:f,}. Generalize unquoted string recovery.
    • 1.1.120
      • revert UTC time change; keep accuracy.
    • 1.1.119
      • missed the toFullYear -> toUTCFullYear of the date.
    • 1.1.118
      • treat \u00A0 the same as a ' ' (space). Visually they are the same, so in the interst of being human readable, it would make sense the machine should read it the same way.
      • fix failure to encode millisecond into timestamp.
    • 1.1.117
      • Fixes reviving a class in a class in a map referencing the class in the map, and then finishsing map.class.class before finishing map.class
      • Fixes reviving references after another prototype revival. (map followed by a key with a reference).
      • restore handling empty object arguments {,,a:3,,,,,b:4,,,} results in {a;3,b:4}.
      • Added some tests which caused the above failures; updated ancient tests to account for
      • top level <string><object> in a stream to seprate with <string><ws><object> which is valid for the test.
    • 1.1.116
      • Provides 'browser', and 'module' entry points. Improves module support.
      • Fixes an issue with references in arrays after other objects.
      • Fixes unclosed ref array state, for ref[], [].
      • Resolves an internal state meaning that overlapped meaning of default and pushed.
    • 1.1.115
      • publish minor doc updates
    • 1.1.114
      • Cricial Fix - clear arrayType when opening a new object or array (circular object decode)
      • Reference fix when referencing the root node.
    • 1.1.113
      • fix leftover test code in require.js.
    • 1.1.111
      • fix packaging.
    • 1.1.101
      • Minor patch to get a long miner version
      • fixed base64 decoding to handle terminations better.
    • 1.1.1
      • added Map() builtin type for JS which is type 'map'.
      • Fixed expression which quoted words with 'S' or 's' in them.
      • Fixed Known array types.
    • 1.1.0
      • Added stringifier/parser instance specific registrations for ToJSOX and FromJSOX handlers.
      • removed unicode non-identifier check, prefering instead just the set of structure characters (basically anything which is not caught before the end begins an identifier). This simplifies testing field names for encoding/stringification.
    • 1.0.8 - Sort object fields case insensitively; standardize field ordering.
    • 1.0.7 - Fixed some stream parsing issues with identifiers.
    • 1.0.6 - just updated build products
    • 1.0.5
      • Fix streaming ability
      • consequtive strings only have whitespace to separate them, so identifiers for defining typed-objects cannot have whitespace between them and '{'.
      • (reverted)implement test for non-identifier characters to quote field strings (or not). Implement reading non-identifier characters, and fault if identifier is unquoted and has such a character.
      • implement typed-strings, which can be used to trigger constructors which accept single strings.
      • update readme with typed-strings, typed-arrays, and typed-objects.
      • performance fix; was keeping parser objects forever.
    • 1.0.4 - Be more forgiving about platforms not having BigInt native support.
    • 1.0.3 - Add ability to register prototypes to use for decoding.
    • 1.0.2 - Issue with mutiple leading and trailing spaces. Fix collecting streams of numbers. Fix an issue with nested classes. Add circular reference support.
    • 1.0.1 - Removed modification of object prototypes; instead track object prototype to formatting function in a WeakMap(). Fixed class expansion. Make objects of a class share the same prototype.
    • 1.0.0 - Intial Release.


    MIT. See LICENSE.md for details.


    http://github.com/json5/json5 Inspiring this JSON6 and subsequently this project.


    npm i jsox

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