On Jun 1, 2011, at 5:16 PM, Mike Samuel wrote: > The semantics of all of these are specified in terms of expression > semantics. Every statement or expression is specified in terms of a > triple of (one of (normal, throw, break, continue), value, label).
Alas, only statements have Completion results. Expressions are modeled as having normal completion with a value, and there's a bit of a gap in the spec where a thrown exception unwinds from within an expression to the statement layer. For a deferred proposal to allow statements to be turned into expresisons explicitly, see http://wiki.ecmascript.org/doku.php?id=strawman:let_expressions Implicitly treating statements in expression context as expressions could be done but I think it smells bad on account of turning erronous programs into working programs, and possibly as a WTF teaching moment. These may not be fatal objections, though. TC39 has not really considered making statements into expressions. See also http://wiki.ecmascript.org/doku.php?id=harmony:completion_reform (note: in Harmony for ES.next). /be _______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
