My read of the spec is that thi\u0073 is a ReservedWord and should not be allowed as an Identifer. So the following part of the examples quoted below should be an early error:
var thi\u0073 = 42; The text in 7.6 seems to address this with: "All interpretations of identifiers within this specification are based upon their actual characters regardless of whether or not an escape sequence was used to contribute any particular characters." Luke -----Original Message----- From: es-discuss-boun...@mozilla.org [mailto:es-discuss-boun...@mozilla.org] On Behalf Of Mike Samuel Sent: Monday, June 20, 2011 2:18 PM To: Oliver Hunt Cc: es-discuss Subject: Re: this vs thi\u0073 2011/6/20 Oliver Hunt <oli...@apple.com>: > Without looking at the spec but just based on what I know our lexer (JSC) > does, we won't consider any identifier with escaped characters to be a > keyword, so yes you could make identifiers that technically match language > keywords, but you'd never be able to use them directly (without escaping). You can due to global object aliasing. var thi\u0073 = 42; alert([this.this === 42, // Look ma, no escaping! this["this"] === 42]); // Look ma, still no escaping! works in Firefox. The first is legal because MemberExpression is defined as MemberExpression . IdentifierName not MemberExpression . Identifier and it is only Identifier that is not allowed to be a reserved word Identifier :: IdentifierName but not ReservedWord IdentifierName :: IdentifierStart | IdentifierName IdentifierPart _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss _______________________________________________ es-discuss mailing list es-discuss@mozilla.org https://mail.mozilla.org/listinfo/es-discuss
