The  JSON  Saga Douglas Crockford Yahoo! Inc.
I am a heretic. You have been warned.
I Discovered JSON I do not claim to have invented JSON.  It already existed in nature.  I do not claim to have been the first to discover it.  I gave it a specification and a little website. The rest happened by itself.
2001
State Software 2002
The Very First JSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;,    text:&quot;Hello world&quot;} ); </script></head></html>
The Very First JSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;,    text:&quot;Hello world&quot;} ); </script></head></html>
The Very First JSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;,    text:&quot;Hello world&quot;} ); </script></head></html>
The Very First JSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;,    text:&quot;Hello world&quot;} ); </script></head></html>
The Very First JSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;,    text:&quot;Hello world&quot;} ); </script></head></html>
The Very First JSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;,  do :&quot;test&quot;,    text:&quot;Hello world&quot;} ); </script></head></html>
The unquoted name problem ES3 has a wack reserved word policy. Reserved words must be quoted. I did not want to put the list of reserved words in the JSON spec, so... All keys must be quoted. It significantly simplified JSON. This conforms to Python.
Nested HTML <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {&quot; to &quot;:&quot;session&quot;, &quot; do &quot;:&quot;test&quot;,    &quot; text &quot;:&quot; </script> &quot;} ); </script></head></html>
Nested HTML <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {&quot; to &quot;:&quot;session&quot;, &quot; do &quot;:&quot;test&quot;,    &quot; text &quot;:&quot;< \ /script>&quot;} ); </script></head></html>
JSML JavaScript Message Language
JSON JavaScript Object Notation
JSON was really useful Browser/server communication. Interserver communication. JSON database.
Our customers said “Never heard of it.” “Sorry, our company just committed to XML.” “It is not a standard.”
I bought JSON.org A one-page web site that described JSON. Grammar three ways Simplified BNF Railroad diagrams Informal English A Java reference implementation. And then I retired.
And that’s all I did. A message format in a bottle.
Contributors
Languages ActionScript C C++ C# ColdFusion D Delphi E Eiffel Erlang Fan Flex Haskell haXe Java JavaScript Lasso Lisp LotusScript Lua Objective C Objective CAML OpenLaszlo Perl PHP Pike pl/sql PowerShell Prolog Python R REALbasic Rebol Ruby Scheme Squeak Tcl Visual Basic Visual FoxPro
JSON is the intersection of modern programming languages Simple values number string boolean Sequence of values array, vector, list Collection of named values object, record, struct, hash, property list
Recursive descent value = function () { // Parse a JSON value. It could be an object, an array, // a string, a number, or a word. white(); switch (ch) { case '{': return object(); case '[': return array(); case '&quot;': return string(); case '-': return number(); default: return ch >= '0' && ch <= '9' ? number() : word(); } };
State Machine state = 'go'; stack = []; try { for (;;) { r = tx.exec(source); if (!r) { break; } if (r[1]) { action[r[1]][state](); } else if (r[2]) { value = +r[2]; number[state](); } else { value = debackslashify(r[3]); string[state](); } source = source.slice(r[0].length); } }
Eval if ( /^[\],:{}\s]*$/ .test(text.replace( /\\(?:[&quot;\\\/bfnrt]|u[0-9a-fA-F]{4})/g , '@').replace( /&quot;[^&quot;\\\n\r]*&quot;|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g , ']'). replace( /(?:^|:|,)(?:\s*\[)+/g , ''))) { // In the third stage we use the eval function to compile the  // text into a JavaScript structure. The '{' operator is subject  // to a syntactic ambiguity in JavaScript: it can begin a block  // or an object literal. We wrap the text in parens to eliminate  // the ambiguity. j =  eval ('(' + text + ')');
JSON.parse Part of ECMAScript, Fifth Edition Available now in better browsers everywhere. Very fast. Very reliable.
Languages Arabic  Bulgarian  Chinese  Czech  Dutch  French  German  Greek  Hebrew  Hungarian  Indonesian Italian  Japanese  Korean  Persian  Polish  Portuguese  Russian  Slovenian  Spanish  Turkish  Vietnamese
Ajax! 2005
Improvements Removed comments. Dangerous practices Unnecessary complexity Alignment with YAML Added  e  notation to numbers.
No version number. JSON will not be changed. Stability is more important than any feature we can think of. Perhaps someday it will be replaced.
Minimalism It can fit on the back of a business card.
Influences
Lisp S-expressions 1958
Rebol
JavaScript Python NewtonScript
NeXT OpenStep Property Lists 1993
XML The High Priced Spread
HTML Always bet on angle brackets.
Ask not if it is good enough. Ask if it can be popular enough.
Maybe only something  this simple could work. John Seely Brown, April 2002
Maybe only something this complicated could work. 2002
XMLsucks.org Why XML is technologically terrible, but you have to use it anyway
XML is the standard so shut up. SHUT UP!
XML Alternatives JSON config YAML CanonML HDF SSYN OGDL SDL DL Boulder ONX SMEL Property lists ConfigObj GroovyMarkup ATerms LNML GODDAG JITTs Esis/Pyxie ConciseXML SML TexMecs A specification language Waterken doc UBF Xqueeze Ool atx Grutatxt APT txt2docbook txt2tags AsciiDoc reStructuredText Epytext EtText AFT txt2html Setext Latte Confluence Markdown SmartyPants Textile Atox CDuce MarkupMatrix WikiMl IWML SEXP sfsexp Lambda markup language SXML Better markup tXML SOX SLiP ezex Tanga (NBML) XSLScript & TerseXML Lx NiceXSL PXSL ShoXS XSCS SML MIN MINML ESPX PXML GMarkup ASN BLOB SDXF CTX ASDL WDDX REBOL http://www.pault.com/pault/pxml/xmlalternatives.html
Disruption Threats
It’s not even XML! Who did this travesty?  Let’s find a tree and string them up. Now.  Dave Winer, 2006-12-20
any damn fool could produce a better data format than XML James Clark, 2007-04-06
Use the right tool  for the right job. When your only tool is a wrench, every problem looks like a nail.
Where did the idea come from that data should be represented by a document format?
RUNOFF .SK 1 Text processing and word processing systems typically require additional information to be interspersed among the natural text of the document being processed.  This added information, called &quot;markup&quot;, serves two purposes: .TB 4 .OF 4 .SK 1 1.#Separating the logical elements of the document; and .OF 4 .SK 1 2.#Specifying the processing functions to be performed on those elements. .OF 0 .SK 1
GML :h1.Chapter 1:  Introduction :p.GML supported hierarchical containers, such as :ol :li.Ordered lists (like this one), :li.Unordered lists, and :li.Definition lists :eol. as well as simple structures. :p.Markup minimization (later generalized and  formalized in SGML), allowed the end-tags to be omitted for the &quot;h1&quot;  and &quot;p&quot; elements.
:eol. ::ol. </ol>
Brian Reid’s Scribe @Quote(Any damn fool) ( )  [ ]  { }  < >  &quot; &quot;  ' ' @Begin(Quote) Any damn fool @End(Quote) 1980
Scribe @techreport(PUB, key=&quot;Tesler&quot;, author=&quot;Tesler, Larry&quot;,  title=&quot;PUB: The Document Compiler&quot;,  year=1972, number=&quot;ON-72&quot;, month=&quot;Sep&quot;,  institution=&quot;Stanford University Artificial Intelligence Project&quot;) @book(Volume3, key=&quot;Knuth&quot;,  author=&quot;Knuth, Donald E.&quot;,  title=&quot;Sorting and Searching&quot;, publisher=&quot;Addison-Wesley&quot;, year=1973, volume=3, series=&quot;The Art of Computer Programming&quot;,  address=&quot;Reading, Mass.&quot;)
License The Software shall be used  for Good, not Evil.
I give permission to IBM,  its customers, partners, and minions, to use JSLint for evil.  Thanks very much, Douglas!  Staff Attorney, IP Law IBM Corporation
The JSON Logo
The Impossible Torus
Ambihelical Hexnut
 
 
 
 
www.JSON.org

The JSON Saga

  • 1.
    The JSON Saga Douglas Crockford Yahoo! Inc.
  • 2.
    I am aheretic. You have been warned.
  • 3.
    I Discovered JSONI do not claim to have invented JSON. It already existed in nature. I do not claim to have been the first to discover it. I gave it a specification and a little website. The rest happened by itself.
  • 4.
  • 5.
  • 6.
    The Very FirstJSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;, text:&quot;Hello world&quot;} ); </script></head></html>
  • 7.
    The Very FirstJSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;, text:&quot;Hello world&quot;} ); </script></head></html>
  • 8.
    The Very FirstJSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;, text:&quot;Hello world&quot;} ); </script></head></html>
  • 9.
    The Very FirstJSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;, text:&quot;Hello world&quot;} ); </script></head></html>
  • 10.
    The Very FirstJSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do:&quot;test&quot;, text:&quot;Hello world&quot;} ); </script></head></html>
  • 11.
    The Very FirstJSON Message April 2001 <html><head><script> document.domain = 'fudco.com'; parent.session.receive( {to:&quot;session&quot;, do :&quot;test&quot;, text:&quot;Hello world&quot;} ); </script></head></html>
  • 12.
    The unquoted nameproblem ES3 has a wack reserved word policy. Reserved words must be quoted. I did not want to put the list of reserved words in the JSON spec, so... All keys must be quoted. It significantly simplified JSON. This conforms to Python.
  • 13.
    Nested HTML <html><head><script>document.domain = 'fudco.com'; parent.session.receive( {&quot; to &quot;:&quot;session&quot;, &quot; do &quot;:&quot;test&quot;, &quot; text &quot;:&quot; </script> &quot;} ); </script></head></html>
  • 14.
    Nested HTML <html><head><script>document.domain = 'fudco.com'; parent.session.receive( {&quot; to &quot;:&quot;session&quot;, &quot; do &quot;:&quot;test&quot;, &quot; text &quot;:&quot;< \ /script>&quot;} ); </script></head></html>
  • 15.
  • 16.
  • 17.
    JSON was reallyuseful Browser/server communication. Interserver communication. JSON database.
  • 18.
    Our customers said“Never heard of it.” “Sorry, our company just committed to XML.” “It is not a standard.”
  • 19.
    I bought JSON.orgA one-page web site that described JSON. Grammar three ways Simplified BNF Railroad diagrams Informal English A Java reference implementation. And then I retired.
  • 20.
    And that’s allI did. A message format in a bottle.
  • 21.
  • 22.
    Languages ActionScript CC++ C# ColdFusion D Delphi E Eiffel Erlang Fan Flex Haskell haXe Java JavaScript Lasso Lisp LotusScript Lua Objective C Objective CAML OpenLaszlo Perl PHP Pike pl/sql PowerShell Prolog Python R REALbasic Rebol Ruby Scheme Squeak Tcl Visual Basic Visual FoxPro
  • 23.
    JSON is theintersection of modern programming languages Simple values number string boolean Sequence of values array, vector, list Collection of named values object, record, struct, hash, property list
  • 24.
    Recursive descent value= function () { // Parse a JSON value. It could be an object, an array, // a string, a number, or a word. white(); switch (ch) { case '{': return object(); case '[': return array(); case '&quot;': return string(); case '-': return number(); default: return ch >= '0' && ch <= '9' ? number() : word(); } };
  • 25.
    State Machine state= 'go'; stack = []; try { for (;;) { r = tx.exec(source); if (!r) { break; } if (r[1]) { action[r[1]][state](); } else if (r[2]) { value = +r[2]; number[state](); } else { value = debackslashify(r[3]); string[state](); } source = source.slice(r[0].length); } }
  • 26.
    Eval if (/^[\],:{}\s]*$/ .test(text.replace( /\\(?:[&quot;\\\/bfnrt]|u[0-9a-fA-F]{4})/g , '@').replace( /&quot;[^&quot;\\\n\r]*&quot;|true|false|null|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?/g , ']'). replace( /(?:^|:|,)(?:\s*\[)+/g , ''))) { // In the third stage we use the eval function to compile the // text into a JavaScript structure. The '{' operator is subject // to a syntactic ambiguity in JavaScript: it can begin a block // or an object literal. We wrap the text in parens to eliminate // the ambiguity. j = eval ('(' + text + ')');
  • 27.
    JSON.parse Part ofECMAScript, Fifth Edition Available now in better browsers everywhere. Very fast. Very reliable.
  • 28.
    Languages Arabic Bulgarian Chinese Czech Dutch French German Greek Hebrew Hungarian Indonesian Italian Japanese Korean Persian Polish Portuguese Russian Slovenian Spanish Turkish Vietnamese
  • 29.
  • 30.
    Improvements Removed comments.Dangerous practices Unnecessary complexity Alignment with YAML Added e notation to numbers.
  • 31.
    No version number.JSON will not be changed. Stability is more important than any feature we can think of. Perhaps someday it will be replaced.
  • 32.
    Minimalism It canfit on the back of a business card.
  • 33.
  • 34.
  • 35.
  • 36.
  • 37.
  • 38.
    XML The HighPriced Spread
  • 39.
    HTML Always beton angle brackets.
  • 40.
    Ask not ifit is good enough. Ask if it can be popular enough.
  • 41.
    Maybe only something this simple could work. John Seely Brown, April 2002
  • 42.
    Maybe only somethingthis complicated could work. 2002
  • 43.
    XMLsucks.org Why XMLis technologically terrible, but you have to use it anyway
  • 44.
    XML is thestandard so shut up. SHUT UP!
  • 45.
    XML Alternatives JSONconfig YAML CanonML HDF SSYN OGDL SDL DL Boulder ONX SMEL Property lists ConfigObj GroovyMarkup ATerms LNML GODDAG JITTs Esis/Pyxie ConciseXML SML TexMecs A specification language Waterken doc UBF Xqueeze Ool atx Grutatxt APT txt2docbook txt2tags AsciiDoc reStructuredText Epytext EtText AFT txt2html Setext Latte Confluence Markdown SmartyPants Textile Atox CDuce MarkupMatrix WikiMl IWML SEXP sfsexp Lambda markup language SXML Better markup tXML SOX SLiP ezex Tanga (NBML) XSLScript & TerseXML Lx NiceXSL PXSL ShoXS XSCS SML MIN MINML ESPX PXML GMarkup ASN BLOB SDXF CTX ASDL WDDX REBOL http://www.pault.com/pault/pxml/xmlalternatives.html
  • 46.
  • 47.
    It’s not evenXML! Who did this travesty? Let’s find a tree and string them up. Now. Dave Winer, 2006-12-20
  • 48.
    any damn foolcould produce a better data format than XML James Clark, 2007-04-06
  • 49.
    Use the righttool for the right job. When your only tool is a wrench, every problem looks like a nail.
  • 50.
    Where did theidea come from that data should be represented by a document format?
  • 51.
    RUNOFF .SK 1Text processing and word processing systems typically require additional information to be interspersed among the natural text of the document being processed. This added information, called &quot;markup&quot;, serves two purposes: .TB 4 .OF 4 .SK 1 1.#Separating the logical elements of the document; and .OF 4 .SK 1 2.#Specifying the processing functions to be performed on those elements. .OF 0 .SK 1
  • 52.
    GML :h1.Chapter 1: Introduction :p.GML supported hierarchical containers, such as :ol :li.Ordered lists (like this one), :li.Unordered lists, and :li.Definition lists :eol. as well as simple structures. :p.Markup minimization (later generalized and formalized in SGML), allowed the end-tags to be omitted for the &quot;h1&quot; and &quot;p&quot; elements.
  • 53.
  • 54.
    Brian Reid’s Scribe@Quote(Any damn fool) ( ) [ ] { } < > &quot; &quot; ' ' @Begin(Quote) Any damn fool @End(Quote) 1980
  • 55.
    Scribe @techreport(PUB, key=&quot;Tesler&quot;,author=&quot;Tesler, Larry&quot;, title=&quot;PUB: The Document Compiler&quot;, year=1972, number=&quot;ON-72&quot;, month=&quot;Sep&quot;, institution=&quot;Stanford University Artificial Intelligence Project&quot;) @book(Volume3, key=&quot;Knuth&quot;, author=&quot;Knuth, Donald E.&quot;, title=&quot;Sorting and Searching&quot;, publisher=&quot;Addison-Wesley&quot;, year=1973, volume=3, series=&quot;The Art of Computer Programming&quot;, address=&quot;Reading, Mass.&quot;)
  • 56.
    License The Softwareshall be used for Good, not Evil.
  • 57.
    I give permissionto IBM, its customers, partners, and minions, to use JSLint for evil. Thanks very much, Douglas! Staff Attorney, IP Law IBM Corporation
  • 58.
  • 59.
  • 60.
  • 61.
  • 62.
  • 63.
  • 64.
  • 65.