Re: [whatwg] native ordered dictionary data type in web storage draft
On Tue, 14 Apr 2009, Patrick Mueller wrote: The last paragraph in section 4.6 of the Web Storage draft (10 April 2009), mentions a native ordered dictionary data type. The URL to the section in the draft is here: http://dev.w3.org/html5/webstorage/#database-query-results This is the first time I've seen the requirement for such a beast. You can understand the desire for it, given the context, but still. Does anything else in JavaScript make use of such a data structure? It's not clear to me how you would even use it, without something like a list comprehension, or some other functional construct. It's hard to imagine how someone might make use of the ordered-ness in a plain old for/in loop, for instance. It would also be impossible, in the JavaScript in use today, AFAIK, to emulate this with user-land JavaScript. On Tue, 14 Apr 2009, Aryeh Gregor wrote: It says that JavaScript should just use Object. Isn't that, essentially, an ordered dictionary? On Tue, 14 Apr 2009, James Graham wrote: Yes. Indeed there are compatibility requirements for the ordering of ordinary user-created Object Objects in web browser implementations; the order of enumeration must be the same as the order of insertion of the properties. On Tue, 14 Apr 2009, Patrick Mueller wrote: Interesting. I guess this is a JavaScript in web browser implementation difference from the JavaScript spec. Following the links in jresig's blog post http://ejohn.org/blog/javascript-in-chrome/ in the for loop order section. Still doesn't seem like it makes sense to go ahead and build dependencies on this (unfortunate, IMO) behavior. On Tue, 14 Apr 2009, Aryeh Gregor wrote: Isn't HTML5 all about mandating and building dependencies on unfortunate but entrenched behavior? On Tue, 14 Apr 2009, Patrick Mueller wrote: This seems slightly different because it's making a dependency on (unspec'd) JavaScript behavior. Though I'd guess there are other examples. This one may also be significant in that, as we start to see JS usage in other environments, like servers, folks may want to reuse something like the sql access defined in here in those environments. Who wants two different ways to talk to sql? It would be nice for this bit to be as clean as it can be. On Tue, 14 Apr 2009, Maciej Stachowiak wrote: FWIW I believe the next version of the ECMAScript spec will specify the order of for..in enumeration. On Tue, 14 Apr 2009, Patrick Mueller wrote: Checking some EcmaScript spec pages, like this one: http://wiki.ecmascript.org/doku.php?id=es3.1:es3.1_proposal_working_draft it appears that current versions of the spec have basically removed the description that the properties are unordered, without specifying that they're ordered, or how their ordered. But a step in the 'right' direction, I suppose. On Tue, 14 Apr 2009, Jonas Sicking wrote: As I understand it, the web already depends on this behavior. IIRC EcmaScript 3.1 is going to mandate this behavior, so it'll be specced behavior soon. Based on the comments above, I have not changed anything in the spec. -- Ian Hickson U+1047E)\._.,--,'``.fL http://ln.hixie.ch/ U+263A/, _.. \ _\ ;`._ ,. Things that are impossible just take longer. `._.-(,_..'--(,_..'`-.;.'
[whatwg] native ordered dictionary data type in web storage draft
The last paragraph in section 4.6 of the Web Storage draft (10 April 2009), mentions a native ordered dictionary data type. The URL to the section in the draft is here: http://dev.w3.org/html5/webstorage/#database-query-results This is the first time I've seen the requirement for such a beast. You can understand the desire for it, given the context, but still. Does anything else in JavaScript make use of such a data structure? It's not clear to me how you would even use it, without something like a list comprehension, or some other functional construct. It's hard to imagine how someone might make use of the ordered-ness in a plain old for/in loop, for instance. It would also be impossible, in the JavaScript in use today, AFAIK, to emulate this with user-land JavaScript. -- Patrick Mueller
Re: [whatwg] native ordered dictionary data type in web storage draft
On Tue, Apr 14, 2009 at 10:18 AM, Patrick Mueller pmue...@muellerware.org wrote: This is the first time I've seen the requirement for such a beast. You can understand the desire for it, given the context, but still. Does anything else in JavaScript make use of such a data structure? It says that JavaScript should just use Object. Isn't that, essentially, an ordered dictionary? (My knowledge of PHP is better than my JavaScript -- in PHP, the *only* native array type is an ordered dictionary.)
Re: [whatwg] native ordered dictionary data type in web storage draft
Aryeh Gregor wrote: On Tue, Apr 14, 2009 at 10:18 AM, Patrick Mueller pmue...@muellerware.org wrote: This is the first time I've seen the requirement for such a beast. You can understand the desire for it, given the context, but still. Does anything else in JavaScript make use of such a data structure? It says that JavaScript should just use Object. Isn't that, essentially, an ordered dictionary? Yes. Indeed there are compatibility requirements for the ordering of ordinary user-created Object Objects in web browser implementations; the order of enumeration must be the same as the order of insertion of the properties.
Re: [whatwg] native ordered dictionary data type in web storage draft
On Tue, Apr 14, 2009 at 1:54 PM, Patrick Mueller pmue...@muellerware.org wrote: Still doesn't seem like it makes sense to go ahead and build dependencies on this (unfortunate, IMO) behavior. Isn't HTML5 all about mandating and building dependencies on unfortunate but entrenched behavior?
Re: [whatwg] native ordered dictionary data type in web storage draft
Aryeh Gregor wrote: On Tue, Apr 14, 2009 at 1:54 PM, Patrick Mueller pmue...@muellerware.org wrote: Still doesn't seem like it makes sense to go ahead and build dependencies on this (unfortunate, IMO) behavior. Isn't HTML5 all about mandating and building dependencies on unfortunate but entrenched behavior? web storage is not yet entrenched. Unless you count Safari :-) This seems slightly different because it's making a dependency on (unspec'd) JavaScript behavior. Though I'd guess there are other examples. This one may also be significant in that, as we start to see JS usage in other environments, like servers, folks may want to reuse something like the sql access defined in here in those environments. Who wants two different ways to talk to sql? It would be nice for this bit to be as clean as it can be. -- Patrick Mueller
Re: [whatwg] native ordered dictionary data type in web storage draft
On Tue, Apr 14, 2009 at 10:54 AM, Patrick Mueller pmue...@muellerware.org wrote: James Graham wrote: Aryeh Gregor wrote: On Tue, Apr 14, 2009 at 10:18 AM, Patrick Mueller pmue...@muellerware.org wrote: This is the first time I've seen the requirement for such a beast. You can understand the desire for it, given the context, but still. Does anything else in JavaScript make use of such a data structure? It says that JavaScript should just use Object. Isn't that, essentially, an ordered dictionary? Yes. Indeed there are compatibility requirements for the ordering of ordinary user-created Object Objects in web browser implementations; the order of enumeration must be the same as the order of insertion of the properties. Interesting. I guess this is a JavaScript in web browser implementation difference from the JavaScript spec. Following the links in jresig's blog post http://ejohn.org/blog/javascript-in-chrome/ in the for loop order section. Still doesn't seem like it makes sense to go ahead and build dependencies on this (unfortunate, IMO) behavior. As I understand it, the web already depends on this behavior. IIRC EcmaScript 3.1 is going to mandate this behavior, so it'll be specced behavior soon. / Jonas
Re: [whatwg] native ordered dictionary data type in web storage draft
On Apr 14, 2009, at 1:03 PM, Patrick Mueller wrote: Aryeh Gregor wrote: On Tue, Apr 14, 2009 at 1:54 PM, Patrick Mueller pmue...@muellerware.org wrote: Still doesn't seem like it makes sense to go ahead and build dependencies on this (unfortunate, IMO) behavior. Isn't HTML5 all about mandating and building dependencies on unfortunate but entrenched behavior? web storage is not yet entrenched. Unless you count Safari :-) This seems slightly different because it's making a dependency on (unspec'd) JavaScript behavior. Though I'd guess there are other examples. FWIW I believe the next version of the ECMAScript spec will specify the order of for..in enumeration. Regards, Maciej
Re: [whatwg] native ordered dictionary data type in web storage draft
Maciej Stachowiak wrote: On Apr 14, 2009, at 1:03 PM, Patrick Mueller wrote: This seems slightly different because it's making a dependency on (unspec'd) JavaScript behavior. Though I'd guess there are other examples. FWIW I believe the next version of the ECMAScript spec will specify the order of for..in enumeration. And that's another way to resolve the issue! :-) Checking some EcmaScript spec pages, like this one: http://wiki.ecmascript.org/doku.php?id=es3.1:es3.1_proposal_working_draft it appears that current versions of the spec have basically removed the description that the properties are unordered, without specifying that they're ordered, or how their ordered. But a step in the 'right' direction, I suppose. -- Patrick Mueller
