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Type system (separate sections below for structural and nominal types)ES4 RITamarin+ESCSpidermonkeyRhinoFutharkMbedthisJSCoreTestsBase documents, tickets, minutesCommentsSpec draftAdobe priMozilla priOpera priGoogle priEmbedthis Ejscript priApple priMicrosoft pri

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 This column will reference the actual spec documents, either speclets that are work in progress or spec parts authored by the Editors.Bright green=essential, light green=useful, white=neutral, red=undesirable, ?=don't understand what feature this is or the polarity of what yes/no would mean

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Type system (separate sections below for structural and nominal types)

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Type definitions (type x = )1100010proposals:type_definitions, #247, #39

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Parameterized type definitions (type x.<T> =)1000000?Iterators

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Subtyping, type compatibility1000010AS3, #328, #122, #127, #262, Note! more here (Cormac's work, sundry discussion pages in the wiki)? (unclear on what this implies)

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DontDelete is not the same as fixture1000010#233??? (don't understand implications of this)

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Type annotations on variables, parameters, and in function return types1000010AS3, #71

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Type annotations on destructuring patterns1000000?

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Type annotations on object and array literals1000010?, #126#370 (new on March 7) proposes semantics for nominal types too

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"is" operator1100010proposals:is_as_to, #309, #103, #73

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"cast" operator0000010proposals:is_as_to, #309, #103rename it to "as"?

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"type" operator1000000proposals:syntax_for_type_expressions, #309, #103

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"wrap" type operator0000000?, #309, #103, #73wrap meta-programming is outside the language (maybe in module system, if there is one)Revised 3/28

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"like" type operator0000000#258, #309, #103, #73, #244Revised 3/28: Now a predicate and function parameter/result syntactic sugarRevised 3/28

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Nullability annotations in type expressions1000000proposals:nullability, #229

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Type conversion between primitive types1100010ES3, proposals:numbers, #246, #345, #346, #113, #38No user-defined conversions

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Wrapping of primitive types0000010ES3, #281
turn off?

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Inferred function types1000000#48

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Reflected type objects implement type meta-object interfaces0000010proposals:meta_objects, #208, #232, #199

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Structural types

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Record types1100000proposals:structural_types_and_typing_of_initializers, #219

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Array types1100010proposals:structural_types_and_typing_of_initializers, #249, #120, #66[...T]Revised 3/28

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Tuple types1100000proposals:structural_types_and_typing_of_initializers, #249, #120, #66eg, [T] or [T,U,V]Revised 3/28

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Function type1000010proposals:structural_types_and_typing_of_initializers, #153

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Union type1000000proposals:switch_class, #218, #308, #300

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"*" ("Any") type1100000AS3

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"undefined" type1000010proposals:syntax_for_type_expressions

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"null" type1000010proposals:syntax_for_type_expressions

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Nominal types

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Classes1100010AS3, #166, #208, #247, #289, #6, #88, #139

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Interfaces1100010AS3, #210, #335, #207if meets DOM use case

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Inheritance1100010AS3

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Non-nullable classes1000010proposals:nullability

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Settings1100010proposals:nullability

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super() call in settings1000010?

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Parameterized classes1000000?

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Parameterized interfaces1000000proposals:type_parameters

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dynamic class Foo1000010AS3

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final class Foo1100010AS3

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<namespace> class Foo1100010AS3not sure what this syntax means)

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parameterized class C.<T> has statics per instantiation not once for all C.<T>1000010Language overview(no given our vote on parameterized types in general, though if they exist this makes sense)

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prototype method1000000proposals:builtin_classes, #75

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get/set method1100010AS3

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static method1000010AS3, #74

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Method overriding1000010#9

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meta::get / meta::set method0000000#214

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meta::has method0000000#214

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meta::delete method0000000#214, #157

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meta::invoke method0000000#214, #173

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static property1100010AS3

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Structure

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Namespaces (namespace foo = ...)1100010AS3, #289

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Predefined namespaces (__ES4__, intrinsic, iterator, meta, reflect)1000010proposals:intrinsic_namespace, #149, #248, #91, #62, #67(only the ones it makes sense to have in light of other votes)

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Name lookup algorithm0000010#233, #141, #33, #142? (do not understand this but if it slows down untyped code then no)

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use namespace foo1100010AS3, proposals:namespace_shadowing

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use default namespace foo1000010?, #242

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pragma syntax and restrictions on same0000010proposals:syntax_for_pragmas, #282

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Blocks {...}1111110AS3This item refers to the ability to have top-level blocks that boil away during parsing, they are useful in expressing eg program units? (unclear on how/whether this differs from ES3)

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packages, import1100000AS3, #283, #335, #116out of time, needs too much workNeed to solve isolation / inadvertent name capture problems among packagesNo on current design but purely URI-based statically detectable import is essential

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private package0000000proposals:local_packages

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internal / public variables1100010AS3, #33, #81

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private, protected, public: how they can be used0000010#90, #33, #81?

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Program units0000010proposals:program_units, #271, #333, #272, #273next timeProbably better done in HTML. Also need to solve asynchronous loading problem.No on current design but purely URI-based statically detectable import is essential

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Declarations

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const1111110JS1.5, AS3, #112

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let1011010proposals:block_expressions, #280, #253, #347Revised 3/27

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let const1000010proposals:block_expressions, #253

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let function0000000proposals:block_expressions, #253

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let expressions1000000proposals:block_expressionsRevised 3/28

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Destructuring Assignment1011100proposals:destructuring_assignment

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Statements

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let statements1011010proposals:block_expressions, #240, #85

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"for each" statement0100010E4X; AS3

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for .. in order0111010proposals:bug_fixes [FOR.IN.LOOP.CREATION.ORDER]

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for .. in loops on null, undefined0111010proposals:bug_fixes

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hide fixtures and namespaced properties in for .. in operations1000010#55hide

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"switch type" statement0000010proposals:switch_class, #163, #41, #252

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Typed "try-catch" statement0100010AS3

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reformed with statement0000000proposals:reformed_with, #252

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Operators

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Comparison Order1111010proposals:bug_fixes

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"eval"0000000ES3, proposals:resurrected_eval, #226, #235, #297intention is good, not done yet?yes to eval operator / function distinction, no to strict mode weirdness or other changes

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&&=0000010AS3

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||=0000010AS3

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"in"0000000#241

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typeof0000010#251, #250Leaves typeof alone

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Operator Overloading0000010proposals:generic_functions; proposals:operators, #140No accepted proposalsNext time

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Iteration

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interator namespace1000010proposals:iterators_and_generators

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InterableType0000010proposals:iterators_and_generators

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iterator::get1000010proposals:iterators_and_generators

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iterator::next1000010proposals:iterators_and_generators

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iterator::close0000000proposals:iterators_and_generators

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iterator::StopIteration1000010proposals:iterators_and_generators

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ItemizableType0000000proposals:iterators_and_generators

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iterator::getKeys0000010proposals:iterators_and_generators

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iterator::getValues0000010proposals:iterators_and_generators

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iterator::getItems0000010proposals:iterators_and_generators

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Tail calls1000000proposals:proper_tail_calls, #215, #323deferdefer

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Generators1010000proposals:iterators_and_generatorsneeds syntactic work

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Array Comprehensions1010000proposals:iterators_and_generators

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"this generator"0000000proposals:remove_the_arguments_object

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Function

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Nullability0000000proposals:nullability, #73, #71, #1

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Function.bind1000000proposals:static_generics

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Function.call1000000proposals:static_generics

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Function.apply1000000proposals:static_genericsresolve this vs. splat

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Rest arguments1100010AS3, #96

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Generic Functions0000000proposals:generic_functions, #245Next time

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Default argument values1100010AS3, #2

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"let function"0000000proposals:block_expressions

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"this function"0000000proposals:remove_the_arguments_object

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arguments object1000000proposals:bug_fixes, #27, #26

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avoid propagating the global object as 'this' when functions are not invoked as method1000010proposals:bug_fixes, #348, #276strict mode onlydoes not seem safe for compat

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type annotations on this1000000proposals:builtin_classesEssential for modeling prototype properties in the language

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Splat operator1000010#357

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Function constructor1000000ES3, #172minor syntax issues?

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toString fixes1000000#174

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Expression closures1010000proposals:expression_closures

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Object literals

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Object literal syntax1000010ES3, proposals:bug_fixes, #164, #165, #219, #319

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Trailing commas1111110proposals:bug_fixes

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const before id0000000?Draft circulated on es4-discuss on 20 March, "Object initializers"

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var before id0000000(Email discussion, analogous with const annotations but just DontDelete, not ReadOnly)Same as for const?

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get and set special forms0000000JS1.5, #12, #13

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namespace qualification0000010#30Iterators, catchalls

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Object

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Destructuring1011100proposals:destructuring_assignment, #111

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field names0000000#29, #313namespaces only

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Global object

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Constant bound types1000000#123 (Note, versioning implications need to be recorded here)

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undefined, NaN, Infinity are constant1011010proposals:bug_fixes

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Math object0000000#220, #171, #8, #83

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encodeURI/decodeURI fixes0000000#148

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hashcode0000010proposals:hashcodes, #152, #52

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global (Global object)0000010proposals:globals, #152, #230

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parseInt0000000ES3, #274

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parseFloat0000000ES3, #274

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isIntegral0000000#161follows isFinite precedent

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copysign0000000#161in double and decimalput in double classPut it into double classPut it into double class

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sign0000000#161in double and decimalput in double classPut it into double classPut it into double class

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__MAX_ECMASCRIPT_VERSION__10000100proposals:versioningProblem needs to get solved somehow

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RegExp

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RegExp Reconstruction1000000proposals:bug_fixes [REGEXP.CONSTRUCTION]

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Readable RegExps (/x)0000000proposals:extend_regexps, #254, #194

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Comment subpatterns1000000proposals:extend_regexps

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Lexer RegExp (/y)0000000proposals:extend_regexpsRevised 4/21

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Named Regexp Submatches (and via backreferences)0000000proposals:extend_regexps, #255, #256, #268

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RegExp Unicode character classes0000000proposals:extend_regexps, #14

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RegExp Character Set Subtraction and Intersection0000000proposals:extend_regexps

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/regexp/('test')0010100proposals:extend_regexpsagainst based on experience

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typeof /regexp/ == 'object'1100100#251ES3 mandates this

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match and nCapturingParens0000000#56

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lastIndex behavior0000000#195

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More permissive charsets0000000#261

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String

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Single-Character Substrings1111110proposals:bug_fixes [STRING.CHARAT.BRACKETS]

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Triple-quoted strings0000000proposals:triple_quotesBigger fish to fry

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Backslash-newline in strings1111110proposals:bug_fixes [BACKSLASH.NEWLINE.IN.STRINGS]? (why not just allow multiline strings w/o special delimeter?)

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Slicing [5:2:-1]0000000proposals:slice_syntax

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String Generics1010000proposals:static_generics

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trim method1000010proposals:string.prototype.trim

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replace named submatches0000000#286

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Array

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Destructuring1011100proposals:destructuring_assignment

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Operations on arrays with structural type0000000#320Slicing a tuple returns an array, but what about the types? Needs a coherent proposal. Probably the most reasonable is to just return an Array, this is really an edge case.

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Array literal1000010ES3, proposals:bug_fixes, #164, #165, #68

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Slicing [5:2:-1]0000000proposals:slice_syntax

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Array Generics1010000proposals:static_genericslibrary.pdf

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indexOf()1111010proposals:static_genericslibrary.pfd

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lastIndexOf()1111010proposals:static_genericslibrary.pdf

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every()1111010proposals:static_genericslibrary.pdf

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filter()1111010proposals:static_genericslibrary.pdf

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forEach()1111010proposals:static_genericslibrary.pdf

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map()1111010proposals:static_genericslibrary.pdf

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some()1111010proposals:static_genericslibrary.pdf

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reduce()0010000proposals:static_generics, #156library.pdf

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reduceRight()0010000proposals:static_generics, #156library.pdf

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New builtins

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int1100010AS3; proposals:numbers, #203, #182, #4, #3#371 proposes removallibrary.pdf(with machine int math semantics, not double math semantics)

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uint1100000AS3; proposals:numbers, #203, #183, #4, #3, #51#371 proposes removallibrary.pdf(with machine uint math semantics, not double math semantics)

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double1100010proposals:numbers, #203, #3library.pdf

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decimal1100110proposals:decimal, #222, #203, #187, #3library.pdf

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Number literal suffixes1000100proposals:numbersm

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string1100010ES3, #203library.pdf

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byte1000000#234, #203Not accepted

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boolean1000010?, #203

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AnyNumber, AnyString, AnyBoolean1000010proposals:numbers, #181, #223library.pdf

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DecimalContext0000000#222, #203quantize and round methods instead

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JSON0000000proposals:json_encoding_and_decoding, #212, #201, #203, #202(not current proposal but JSON API is essential)

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Map1000000proposals:dictionary, #203, #146library.pdf(but not parametric)

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Vector1000000proposals:vector, #196, #197, #203, #198library.pdf

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Name1000000proposals:name_objects, #203library.pdf

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Namespace0000010?, #204, #203library.pdf

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NamespaceSet0000000proposals:name_objects, #205, #203

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NamespaceSetList0000000proposals:name_objects, #205, #203

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ControlInspector0000000proposals:stack_inspection, #203library.pdfoptional is bad for the Web

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Type meta-objects0000010proposals:meta_objects, #200, #205

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Numbers and arithmetic

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uint32ops (add, sub mul, div, mod, neg, and, or, xor, not, sll, srl, sra, ror, rol)1000000#216

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Number.parse0000000#275

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int.parse, uint.parse, double.parse, decimal.parse0000000#317ok if those types are presentok where the type is presentok if those types are presentok if those types are present

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double.explode, double.implode, decimal.explode, decimal.implode0000000#160double.explode returns pair of unsigned integer values

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use decimal <context>0000110#222, #221Not as defined in proposals:numbersnot a pragma

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Date

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Date ISO-86010000000proposals:date_and_time, #147(prefer web-compatible definition)

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Date nanoAge method0000000proposals:date_and_time

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Overridable defaults?0000000#193

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Date.parse1000000#134, #135, #136

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(more changes here)0#129, #191?

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Misc

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use strict0000010proposals:strict_and_standard_modesonly as "good taste" modemay want more runtime semantic changesconcept ok, details differ(don't like modes or optional features)

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use standard0000010proposals:strict_and_standard_modesTalking about the specific pragma, not the notion of a standard modeill-defined idea in general

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do-while semicolon insertion0000010proposals:bug_fixes

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Keywords in safe contexts0000010proposals:reserved_words

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Unicode updates0000000proposals:update_unicode, #213, #179, #37, #170Current proposal is unsoundNeed sound proposal

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Line terminator normalization100000proposals:line_terminator_normalization

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ES4 RITamarinSpidermonkeyRhinoFutharkMbedthis

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Types1074429211291

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Classes15700012

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Structure7511110

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Declarations513323

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Statements243307

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Operators452588348

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Iteration702008

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Functions1221004

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Objects201103

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RegExp311020

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String323222

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Array10711818

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Builtins400013

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Misc000004

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Tickets that may be important but are unaccounted for above#11, #167