User:Waldo/ES6 testing

Things to be tested:

• The ordinary/exotic object distinction (relevant to proxies, arrays, and the exotic objects mentioned in 8.4/8.5)
• proper parsing of template literals, wrt the InputElementTemplateTail goal symbol -- ASI
• Unicode format-control characters within template literals -- line terminators as well
• identifier goal symbols seem to have changed some -- to use the Unicode properties ID_Start and ID_Continue (and also _/$/<ZWJ>/<ZWNJ>) -- may need testing
• new keywords: class, continue, const, export, import, super (possibly all reserved before, tests needed for their new semantics, and places that still forbid them)
• likely-new keyword yield
• regular expression literals syntax rules appear different -- maybe something to do here, maybe not
• "8.1.6.4 Well-Known Symbols and Intrinsics": are these directly observable, or only indirectly through spec algorithms' uses of them?
• 8.2.4.3 GetThisValue(V): how is this used, where, maybe needs tests (if not just some sort of refactoring of |this| keyword handling, not sure yet)
• the Property Descriptor type now has an optional Origin field -- possibly/likely used for property descriptors returned from proxy hooks -- needs testing
• new HasOwnProperty hook -- previously this was simply derived from GetOwnProperty
• new Enumerate and OwnPropertyKeys hooks with well-defined semantics for for(var i in o) and Object.getOwnPropertyNames/keys -- visible in proxies
• functions (ordinary function objects, 8.3.15.1) have a bunch more internal data properties to track -- affecting semantics in various ways; realms are perhaps the most important one (corresponding to the multiple-globals problem in web browsers)
• |new| on a function whose Prototype has been changed to null/undefined -- semantics of this are still partially up in the air
• there seems to be a requirement that |(function() { "use strict"; }).caller === null| per 8.3.15.3 which might be a change from ES5 -- needs investigation, testing
• BuiltinBrand is new, may affect every place that currently does exact-class checks (or exact-class-modulo-other-globals checks)
• String exotic objects: new internal ops defined for them, may require more testing for out-of-range -- also for negative indexes, which in the current spec seem to be passed through abs() (!)

New features:

• template literals (nee quasis)
  • templates with zero or more substitution parts
• binary integer literals
• floating point hex literals (maybe? not added yet, might be)
  • \u{} Unicode escape sequences* \u{HexDigits} is a syntax error if HexDigits > 1114111 (0x10FFFF)
  • \u{} with a surrogate-pair number, other reserved code points
• Binary Data proposal (8.2.1)
  • data block type
• super
  • implicates Super References (8.2.4), and the super keyword -- something to do with calling superclass methods, and similar things; haven't grokked details yet
• ToPrimitive is now explicitly hookable in objects (doesn't use toString/valueOf properties), using a well-known symbol/intrinsic
• scriptable Proxy objects (8.5) (direct proxies)