Draft Specification for ES.next (Ecma-262 Edition 6)
This page contains a historical record of working draft of the ES.next specification prepared by the project editor.
Errors in the current draft should be reported as bugs at bugs.ecmascript.org. Report the version you are reading, and an appropriate “component” (editorial issues, technical issues, etc.). Such bug reports are particularly useful for specific bugs such as misspellings or errors in algorithms.
An unofficial HTML version of the Edition 6 working draft is usually available at http://people.mozilla.org/~jorendorff/es6-draft.html]. Note that this HTML version may not always be up to date with the current working draft below.
Some Guidelines for Reading these Drafts
For now, all draft found here are snapshots taken of the project editor’s working draft. Snapshots are taken at fairly arbitrary points in time. The drafts are still far from being complete, often have incomplete treatment of new features, and sometimes are captured in the middle of some major refactoring. Many features that are intended for the next edition may not yet be included in any particular draft. Incomplete material and undecided issues are often marked with marginal notes within the document.
It is reasonable to assume that the editor is aware of the major inconsistencies or missing material, but you can’t over report. So if you see something that you think is important to capture, file a bug.
The rationale for design decisions, are not generally part of the specification. You can find background information on this wiki and in the archives of the es-discuss mailing list. If you want to discuss why certain decisions were made or want to argue for an alternative then you should post messages about specific issues to es-discuss.
The primary target audience of this specification is implementors who must create highly interoperable ECMAScript implementations. In one sense, the specification is all about the edge cases that implementors must get exactly right in order to be completely interoperable. Next comes the authors of interoperability and conformance test suites, such as test262. They need to write tests that help implementors conform to the specification. Third in priority, are sophisticated authors and educator. These are the people who will teach the language to the world, and like implementors, they need to know (or at least lookup) edge case behavior.
This is not intended as a document for everyday ECMAScript coders (although some will use it). It is also not a tutorial on either language design in general, language theory, or the design process behind its creation. The spec. also isn’t particularly targeted towards academics. We certainly want to have a sound language and where necessary TC39 members may prove characteristics of certain features. But such material is not necessarily included in the specification.
We generally within the specification try to minimize tutorial material (eg examples) and redundancy between normative prose descriptions and normative algorithms. Redundant descriptions has historically resulted in internal inconsistencies. We have also seen cases where implementors follow incomplete prose descriptions without referring to the more complete algorithm. For these reasons, much of the redundant prose from previous editions is being converted into non-normative notes. In general, examples are only used if they seem necessary to clarify some difficult to understand normative point. Sometimes an example is used in order to make it clear that some unusual design point is intentional and not a bug in the specification. The spec. generally does not discuss what a feature is good for or how to use it. Having said all that, the spec. doesn’t always follow these guidelines. We working on the 6th edition of a fifteen year old document and sometimes older material doesn’t follow newer conventions. Cleaning this up is mostly a “if time is available” task.
We generally don’t include non-normative rationale material. It would be great for somebody to create a document explaining all of the design rationales for the language. But I the editor doesn’t have the time to do both that and to also produce the actual specification. Rationale material can be mined from es-discuss threads, on wiki.ecmascript.org, and in TC39 minutes.
Current Working Draft
May 14, 2013 Draft doc
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Changes marked as “Rev 15”
Changes include:
Made Symbols a primitive type
Added semantics for generator function and generator method definitions
Added semantics for array comprehensions and generator comprehensions
Added semantics for yield and yield*
Replaced StopIteration exception with nextResult objects
Updated for-in/of semantics to use new generator protocol
Made Arrow function and concise method formal parameters “strict”
Added Object.setPrototypeOf function
Made Function constructor subclassable
Added Array.prototype.find and findIndex
Added Math.imul
Added ArrayBuffer.isView to check for ArrayBuffer view objects
Added Clause 15.19 defining the content of the build-in iteration module. Contains built-ins needed to support generators
Disallow Unicode escapes as RegularExpressionFlags
Moved Object.prototype.__proto__ back to Annex B. It’s a simple access or that is not Realm specific.
Added in Annex B __proto__ property keys in object literals
Added placeholder in Annex B for defining syntax of html-like comments
In Annex B, first cut at block-level function declaration legacy semantics
Added RegExp.prototype.compile to Annexs B
Fixed handling of negative integer indices for typed arrays. Elimiante ToPositiveInteger abstract operation
Typed Arrays are allowed to store values using native endianess.
Fixed various bugs in class declaration semantics
Dates never expose -0 as a time value
Resolved Bugs: 1469, 1461-1460, 1458, 1452-1451, 1449, 1446, 1442-1435, 1433, 1432-1414, 1411-1407, 1404, 1403-1401, 1399-1397, 1395-1392, 1389-1376, 1374-1366, 1363-1361, 1359, 1357-1355, 1352-1348, 1346, 1344-1342, 1340-1338, 1336-1318, 1316, 1314-1301, 1299-1296, 1294-1291, 1289-1288, 1286-1285, 1284, 1282, 1280-1277, 1272, 1253, 1117, 387
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Older Drafts
March 8, 2013 Draft doc
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Changes marked as “Rev 14”
Changes include:
Class bodies are now always strict
static methods may now be defined in ClassBody
Updated comprehension syntax to use left-to-right order
Eliminated is and isnt operators
added grammar productions to allow unqualified super to be used after new operator
expression to the right of of in for-of now restricted to being AssignmentExpression
Almost all Chapter 15 constructors are now specified to have an @@create method and are initialized in a manner that supports subclassing. (still need to work on Function)
Added Object.getOwnPropertyKeys function
Added Object.is function
Tentatively added Object.mixin function
Array.from now takes an optional map function
Added String.prototype.normalize method
All String.prototype methods that accept RegExp arguments will now work with subclasses of RegExp
Renamed Number.prototype.toInt to Number.prototype.toInteger
RegExp global, ignoreCase, multiline, source, sticky are now prototype accessor properties rather than instance own data properties. This is needed to support adding web compatible compile method.
Added new RegExp.prototype methods that allow string methods to work with RegExp subclasses: match, replace, search, split, @@isRegExp
Map and Set constructors now accept a =n optional comparator parameter. Only value currently allowed is “is”
ArrayBuffer and TypedArray object length no long restricted to 232 limit
Eliminated all remaining references to [[Class]] and [[NativeBrand]] (except for in some DataView code that needs rewritting anyway)
Added SameValueZero abstraction operation that considers -0 and +0 to be the same value.
Rename [[GetP]] to [[Get]] and [[SetP]] to [[Set]]
Specified that unless otherwise indicated, internal data properties are created when an object is allocated. Internal data properties are now explicitly listed in ObjectCreate abstract operation calls.
internally consolidated [[IsExtensible]]/[[IsSealed]/[[IsFrozen]] and [[PreventExtensions]]/[[Seal]]/[[Freeze]] into two MOP operations [[HasIntegrity]] and [[SetIntegrity]]. However, no public APIs (Proxy traps and Reflect functions) changed.
Numerous editorial and technical corrections, clarifications, and bug fixes
Resolved Bugs: 1252-1251, 1249-1246, 1243-1241, 1239-1238, 1236, 1234-1233, 1231-1229, 1227, 1225-1224, 1222-1220, 1218-1214, 1212-1209, 1207, 1206, 1205, 1203-1197, 1195-1194, 1190, 1188-1187, 1185, 1182-1176, 1174-1166, 1164-1163, 1157, 1144, 1123, 1110, 1108, 1089, 1081, 1063, 1060, 1051, 1045, 1019, 981, 979, 969, 497, 21, 20
December 21, 2012 Draft doc
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Changes marked as “Rev 13”
This revision generalizing object allocation in order to make it easier to subclass built-ins and other objects with private instance state. TypedArrays are now better integrated into the spec. Cleaned up many typos and issues introduced with the major refactoring in Rev 12.
Changes include:
Well-known Symbols and Intrinsics added as 8.1.6.3
[[HasProperty]] reintroduced as an internal method
Elimianted [[Key]] and updated [[OwnPropertyKeys]] to return an iterator. Object.keys and Object.getOwnProertyNames now uses [[OwnPropertyKeys]].
Restructured ordinary [[Construct]] to looks for and call a @@create method on the constructor. This permits the separate definition of the allocation and initialization actions of constructors. This makes built-ins and other objects that require special allocation to be subclassable but corrects the problem of a single instance be initialized as an instance of multiple such classes. See
https://mail.mozilla.org/pipermail/es-discuss/2012-November/026753.html Added default @@create method for Function.prototype. Restructued Date, Map, WeakMap, Set to use @@create based instance allocation.
Added Indexed Delegation Exotic objects to support array-like indexing of TypedArray objects.
Renamed “items” interator methods to “entires”
Complete reworked ArrayBuffer and TypedArray sections. They now use @@create pattern for allocation and are subclassable. Still not integrated with Binary Data proposal but this is the foundation for doing so.
Resolved bugs: 1161, 1156, 1154, 1152, 1151, 1149-1147, 1145, 1143, 1141-1138, 1135, 1130, 1127, 1122, 1120-1118, 1112, 1107-1099, 1097-1090, 1088, 1086, 1084-1077, 1074-1064, 1062, 1061, 1058, 1056-1052, 1050-1024, 1022-982, 922
November 22, 2012 Draft doc
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Changes marked as “Rev 12”
This is a major revision that takes the first step at reforming the internal Meta-Object Protocol (the “internal methods”) and extending it to support Proxies. Quite a bit of material has moved within the document. The overall document organization is in a state of flux and some sections will be moved in the future. For now, somethings have been temporarily left in their old locations to preserve change markup relative to ES 5.1 that might otherwise get lost.
Changes include:
Reorganized Chapter 8 into separate language type and specification type sub sections
Added Symbol property keys to the definition of the Object Type. terminology migration from talking about “property names” to “property keys”.
Restructured 8.6.2 (now 8.1.6.2) as the abstract interface definition of the internal object MOP. eliminated Table 9 (Internal props of only some objects) and distribute related material to definitions of specific object forms. Moved discussion of internal method invariants plus invariant enforced by proxies into separate place order subsection. This needs a complete rewrite to clearly define the actual internal methods invariants.
MOP changes: Added [[GetInheritance]]/[[SetInheritance]] as internal methods for accessing [[Prototype]] internal prototype chain. Added [[[IsExtensible]]/[[PreventExtensions]]. Replaced [[Get]]/[[Put]] with [[GetP]]/[[SetP]]. At some point we may be able to rename these as [[Get]]/[[Set]]. Eliminated [[GetProperty]], [[CanPut]], [[HasProperty]], [[DefaultValue]]. Added
Keys, [[OwnPropertyKeys]], [[Freeze]], [[Seal]], [[IsFrozen]], [[IsSealed]].
[[DefaultValue]] now part of ToPrimitive with a possible dispatch through a @@ToPrimitive symbol keyed method on objects. Define a @@ToPrimitive method on Date.prototype to take care of special date [[DefaultValue]] rules.
As part of “proto climbing” reform refactored GetValue and PutValue to directly incorporate the logic for property references on primitive values. Eliminated special [[Put]] and [[Get]] for primitive bases.
Eliminated all “strict” arguments to internal methods that were used to request trapping in strict mode”. All such methods now always return true/false success status. It’s up to the called (usually via a convenience function) to throw on failure.
Section 8.3-8.5 now provided the concrete implementation of the MOP interface for all ordinary and exotic object forms defined in the specification. this will eventually move into a new top level section following the current section 10.
Defined Symbol objects as a kind of exotic object. Its internal methods make it stateless and immutable.
In 9.3 added a number of convenience functions that operate at the level of the generic object MOP. These can be thought of as generic “derived” operations that will work with any kind of object. They are now used throughout the specification.
Added Table 25 (incomplete) in 10.3 to define the “intrinsic objects” of a code realm
instanceof operator no longer uses an internal method. Instead, extensible via a @@hasInstance symbol-keyed regular method.
Restated most Object.* reflection functions to delegate to corresponding MOP internal method.
Defined all of the functions in the @Reflect module corresponding to MOP internal operations.
Resolved bugs: 982, 979, 978, 973, 971-969, 966, 960, 958-956, 954-952, 950, 948-945, 943-936, 934-925, 923, 920-914, 912-904, 902-883, 881-873, 870-853, 851-839, 837-818, 808, 785, 672, 591, 400, 150, 100
October 26, 2012 Draft doc
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Changes marked as “Rev 11”
Changes include:
Changed the name of the Program grammar production to Script. Updated the syntax, static and runtime semantics of Script in 14.1
In 10.1, defined the terms “module code” and “generator code”.
Specified semantics of global environment records and and global declaration instantiation semantics in line with the Sept. 2012 TC39 meeting decisions.
Specified WeakMap and Set
Added iterator functions and iterator objects for Array
Added Map clear method
Made Map size an accessor property
Updated function declaration instantiation semantics to reflect Sept. 2012 TC39 discussion of function parameters. However, there are likely to be more changes following the next meeting.
Some refactoring of early errors associated with places that use cover grammars.
Work on semantics of var/function declarations at top levels of functions and scripts.
Updated early error rules for formal function parameters based upon recent es-discuss thread.
Chapter 15 functions now get poison pills for “arguments” and “caller”.
Changed Object.defineProperties to defer exceptions until all property updates are completed.
Stubbed in a place holder for Object.assign.
Made it explicit that Function.prototype does not have a prototype property.
Resolved bugs: 817-813, 812, 810, 805, 804-799, 796, 795, 792, 790-787, 784, 783, 780-777, 761-757, 755-751, 748, 747, 745-735, 733, 732, 726-716, 714, 712, 710, 706-700, 694, 690-683, 681-679, 674, 671-664, 658, 636, 627, 626, 614, 591, 570, 504, 496-494, 414, 401, 357, 312, 265, 260, 247, 214, 182, 153
September 27, 2012 Draft doc
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Changes marked as “Rev 10”
Changes include:
Significant reworking of the use of cover grammars for unambiguously defining assignment restructuring patterns and for arrow function formal parameters.
Renaming of Quasis to Template Strings
Incorporated Class definition semantic decisions from July TC39 meeting
Make concise methods enumerable, as per Sept. TC39 meeting.
A first cut at making Object.prototype.toString extensible via a Unique Symbol extension point.
Started to rough in binary data and typed arrays into Section 15. At this point it is mostly just material copied directly from wiki proposals. Lots of integration and detailed specification work remains.
Fully specified Map builtin as 15.14. This also serves as model for how other new built-in collections will be specified.
Roughed in section 15 places holders for Set, Weakmap, Proxy, and the Reflect module. Feedback on overall organization of this material is welcome.
Many fixes of both unreported and reported bugs, including:256, 464-468,470-479, 482-484,486,488,490-497,499,502,506,506-510,514, 515, 520, 521, 527, 529-537,539-559, 561-564, 566-569, 571, 572, 576, 579-587, 589, 592, 597-599, 601-609,612, 614-616, 618, 620-623, 626, 628-630, 633,635,639-644,650,653
July 8, 2012 Draft doc
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Changes marked as “Rev 9”
Changes include:
Quasi literal added to specification
Initial work at defining tail call semantics (still need to define tail positions in 13.7)
Initial pass at replacing native/host object terminology with ordinary/exotic objects
Clause 6 and others updated to clarify processing of full Unicode source code. Revised usage of “code unit” and “code point”
Specification of Identifiers updated to use current Unicode specification devices
\u{nnnnnn} Unicode code point escapes added
UTF-16 encoding for non-BMP characters in string literals now fully specified
Added functions: String.fromCodePoint, String.raw (a quasi tag function), String.prototype.codePointAt
ECMAScript now requires use of Unicode 5.1.0, normative references updated
A syntactic grammar notation was added for indicating when alternative lexical goals are required
Fixed ES5 missing explicitly setting length in several array functions
Fixed bugs: 368, 388-399, 402-405, 410-413, 415-416,418, 420-428, 430-439, 445-456,458-461
June 15, 2012 Draft doc
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Changes marked as “Rev 8”
Changes from May TC39 Review
Tentative addition of Class Definitions Syntax and Semantics in 13.5 based upon Maximally Minimal Strawman. NOTE-Classes do not yet have full consensus within TC39 and may not survive.
11.1.5 make super references illegal in method definitions within object literals
removed <| and TriangleLiterals
reverted methods to only have bracketed function bodies rather than concise bodies
Removed Object.isObject
Removed String.prototype.toArray
Eliminated requirement for buggy daylight savings time adjustment
Other changes
5.1.1 , 5.2 Defined “chain production” and implicit algorithm pass through for chain productions. Eliminated unnecessary pass through algorithms
Eliminate final remnants of ES1 line number references within algorithm conventions
Moved Literal from lexical to syntactic grammar
Updated keywords list
10.1.2 /10.4 introduce concept of non-ECMAScript functions and execution contexts for them
11.1.4.2 tweaks to Array Comprehension syntax
made it an early error to use a reserved word as a single identifier property definition shorthand
added default value initializers to internal elements and properties of destructuring assignment patterns
corrected major case statement semantic bug from ES5.1
made YieldExpressions illegal in parameter default value initializers
made home object binding of methods contingent upon them actually referencing super
added [[ThisMode]] internal property to functions via FunctionCreate to deal with lexical this binding in arrow functions
made super references and yield expressions early errors in ProgramBody
In Math.sign clarified handling of -0
Added String.prototype
HTML wrapping functions to Annex B
Merged ES5.2 Annex F into Annex D&E
Made Annex F an Informative Summary of Static Semantic algorithms
Fixed bugs 281,340,343,346-349,351-356,358-367,369-376,378-380,382,384-386
May 4 , 2012 Draft doc pdf with change markuppdf without markup
Changes marked as “Rev 7”
Changes include:
Clarified that IdentifierNames can include escape sequences
Added syntax and semantics for Binary and Octal integers
Extended Reference to support super references
Added semantics for super in MemberExpressions and CallExpressions
Added abstract operations for Object and Array creations
Added arrow functions (13.2) and concise methods (13.3)
Preliminary introduction of code “Realms” (contexts with their own globals, intrinsics, etc.) (incomplete)
Added Method Environment Records as part of super support
Extensions to execution contexts needed to support generators, super, and code realms
Eliminated “enter execution context” algorithms by merging them with [[Call]], eval, Program etc.
General migration of most material related to functions and their execution into Chapter 13.
Added additional explicit checks of completion values.
made yield illegal outside of generators
additional work/cleanup on for-in/for-of (prep for array comprehensions)
Started tracking Annex D and E additions
refactored “Creating Function Objects” into separate function and constructor creation abstract operations.
added Object.isObject
added Array.of and Array.from and cleanup Array constructor specification
added String.prototype repeat, startsWith, endsWith, contains, toArray
clarification of Number.MIN_Value for Arm processors (that don’t support denormalized numbers)
added Number.EPSILON,MAX_INTEGER,parseInt, parseFloat,isNaN,isFinite, isInteger, toInt
added Number.prototype.clz
added Math.log10, log2, log1p, expm1, cosh, sinh, tanh, acosh, asinh, atanh, hypot, trunc, sign, cbrt
February 27, 2012 Draft doc pdf with change markuppdf without markup
Changes marked as “Rev 6”
This is an intermediate draft containing incomplete changes.
Changes include:
Eliminated “extended mode” in support of “one JavaScript” plan, all new features are generally available in all modes.
Eliminated various static semantic rules that would be breaking changes in “one JavaScript”
Added support for for-in, for-of, and first cut at lexically scoped for(;;).
Added section B.3.1 with specifies __proto__ feature.
Did spec. changes to implement “completion reform”.
Did most of the work to pervasively use completion results for expressions as well as statements. Still some work to do in sections 10 and 15 but all of expressions and the Array methods have all been updated to handle completion records as general results. See 8.8 for enhance completion record internal
API. Note that observable occurrence points are more precisely specified for many exception that had been informally “thrown” by various specification algorithms.
Added [[Enumerate]] and [[Iterate]] internal methods for normal objects.
Generalized the List special type to also include a Record specification type.
Added an Invoke abstract operation that is used to internally “call methods”
Added syntactic productions for array comprehensions, generators and Generator comprehensions. No semantics yet.
Converted prose specification of labelled statements into algorithmic spec. Added BreakableStatement production that includes IterationStatement and SwitchStatement.
Refactored let/const into a single set of productions and semantics rules.
Many minor edits and typo/bug corrections, see bugs.ecmascript.org for details.
Preliminary work in support of super references and super calls is still incomplete
January 16, 2012 Draft doc pdf with change markuppdf without markup
Changes marked as “Rev 5”
This is an intermediate draft containing incomplete changes.
Changes include:
Various proses descriptions and introductions have been converted into non-normative notes.
Some preliminary work was done in support of super references and super calls (incomplete)
Various editorial minor corrections
Updates to function declaration instantiation in support of extend mode formal parameter scoping decisions made at Nov 2011 TC39 meeting.
Changes to spread in destructing assignment in ArrayLiteral to conform to decisions made at Nov. 2011 TC39 meeting.
Added static and runtime semantics for concise method properties in object literals.
Converted ES5 algorithmic strict mode errors into declarative early errors for Unary and Postfix expressions
Added is and isnt operators
Eliminated “augments” as a possible formal parameter name for extended code
November 7, 2011 Draft doc pdf with change markuppdf without markup
Changes marked as “Rev 4”
Changes include:
New issue bugs: 221,222
Introduced the term “base code” to mean code that is neither strict or extended.
Changed organization and presentation conventions for static and runtime semantics, Note that some parts of the spec. have not yet been switched to the new conventions.
Refactors Literal production to make it easier to talk about non-null literals
Added a [[Strict]] internal property for functions to make it easier to talk about strict mode code. Changed the definition of the [[Code]] and [[FormalParameters]] internal properties of function objects.
Moved function parameter initialization into 10.4.3 “Entering Function Code”
Added semantics for new function parameter forms in extended code.
Refactored Declaration Binding Instantiations into separate subsections for different situations
Added declaration instantiation for extended code functions.
Refactored argument object creation into separate algorithms for strict and non-strict functions.
Made FunctionExpression a PrimaryExpression
Started grammar modifications to support #[ ] and #{ } as agreed to at Sept. TC39 meeting. Incomplete
Added grammar productions for concise methods in object literals. Semantics still to come
First cut at grammar productions for super property access and <| operator
Started migrating some expository text into informative notes.
Added static semantic algorithms for processing lexical scoped declarations
Finished semantics for binding destructuring patterns in declarations, catch parameter, and function formal parameters
Made sure exceptions during processing of default parameter initializes are handled
Major record for semantics of function declaration in section 13
September 23, 2011 Draft doc pdf
Changes marked as “Rev 3”
Changes include:
Resolved as fixed bugs 137, 140,167, 177, 183,184,185,186,187,188,189,190,191,193,196,196
Merged multiple built-in “class” branding internal properties into a single [[NativeBrand]] internal property
In 10.2, change environment records so that both mutable and immutable bindings may be in an initialized state and must be initialized before use via InitializeBinding
In 10.5 added separate algorithm for Block declaration instantiation. Block level declaration instantiations now specified. Function and global level still need to be updated to support let and const
Added a Declaration production to the grammar and changed StatementList to include both Statement and Declaration
Added let and const declarations. var declarations still hoist to function level and must not conflict with a let or const.
Hoisting and temporal dead zone for all block scoped declarations
Added semantics for destructuring binding pattern.
Added appropriate lexical scoping for declarations in bodies of switch and try statements. Note that for statements still need work for declarations in for head.
Added initializers for individual property level bindings in destructure bindings
July 25, 2011 Draft doc pdf
Mostly typo corrections (thanks for all the reports) and corrections to problems that have been reported against ES5.1. See closed 6th edition bugs at bugs.ecmascript.org.
July 12, 2011 Draft doc pdf This is the first working draft of the ES.next specification. Notable changes from the ES5.1 spec include:
5.1.4 Introduction of the concept of supplemental grammars.
5.3 Introduction of concept of Static Semantic Rules
8.6.2 and various places. Eliminated [[Class]] internal property. Added various internal trademark properties as a replacement.
10.1.2 defined the concept of “extended code” that means code that may use new Es.next syntax. Also redefined “strict code” to mean either ES5 strict mode code or extended code.
11.1.4 added syntax and semantics for use of spread operator in array literals
11.1.5 added syntax and semantics for property value shorthand and various semantic helper abstract operations.
11.2, 11.2.4 added syntax and semantics for spread operator in argument lists
11.13 Add syntax and semantics for destructuring assignment operator.
12.2 Added BindingPattern syntax and partial semantics to support destructuring in declarations and formal parameter lists.
13 Added syntax to support rest parameter, parameter default values, and destructuring patterns in formal parameter lists. Also static semantics for them. However, instantiation of such parameters is not yet done. Defined the argument list “length” for such enhanced parameter lists.
15 Clarified that clause 15 function specifications are in effect the definition of [[Call]] internal methods.
15.2.4.2 Respecified toString to not use [[Class]]. Note that adding an explicit extension mechanism is still a to-do.
Annex B Retitled as normative optional features of Web Browser ES implementations
fixed bugs:
Initial Baseline document: doc
This is the starting point for the ES.next spec. It is just the ES5.1 specification with a ES6 draft cover and copyright notice.working_draft_ecma-262_edition_6_10-26-12.docworking_draft_ecma-262_edition_6_03-08-13-nomarkup.pdf
