I would imagine that it's not very easy if you want to retain the
ability to instantiate objects outside the function.
But I'm no expert :)
Ben
On Tue, Nov 18, 2008 at 2:59 PM, Paul Davis <[EMAIL PROTECTED]> wrote:
> If this is easy and you see an implementation, I think it'd be a great
> addition to force the sand boxing of individual functions.
>
> That said, I don't know much about the JS internals so I'm not sure
> how hard it would be to auto detect what might cause side effects
> outside the function and what wouldn't. I've stuck largish objects
> outside the function itself on the assumption that they'll only be
> instantiated once as opposed to once per document.
>
> I have absolutely no idea if that's even necessary though.
>
> Paul
>
> On Tue, Nov 18, 2008 at 9:51 AM, Benjamin Nortier <[EMAIL PROTECTED]> wrote:
>> Should CouchDB not restrict defining state outside the map function?
>> I.e. you should not be able to declare a counter outside the function?
>>
>> On Tue, Nov 18, 2008 at 1:42 PM, Jedediah Smith
>> <[EMAIL PROTECTED]> wrote:
>>>
>>> You can't maintain a state across calls to map functions in this way. Map
>>> functions can be called in any order or in parallel, any number of times on
>>> a particular document and in completely separate environments. They should
>>> not have any side effects or depend on any outside state.
>>>
>>> You should read up on Google's MapReduce and maybe functional programming in
>>> general in order to understand how CouchDB works.
>>>
>>> If you just want to number the results of your view, that can be easily done
>>> by the calling code.
>>>
>>> Adam Groves wrote:
>>>>
>>>> Hi,
>>>>
>>>> I've got the following view:
>>>>
>>>> count = 0;
>>>> function(doc) {
>>>> if(doc.type == "document") {
>>>> count = count + 1
>>>> emit(doc._id, count);
>>>> }
>>>> }
>>>>
>>>> The idea is that I get a list of documents, each having a counter
>>>> value which is incremental. I expected the count values to come out in
>>>> order, but that isn't the case: my first few documents have values of
>>>> 62, 61, 22, 19. I'm not quite sure what's going on here - any ideas
>>>> how the order is being set here?
>>>>
>>>> Regards
>>>>
>>>> Adam Groves
>>>>
>>>
>>
>>
>>
>> --
>> Benjamin Nortier
>> e: [EMAIL PROTECTED]
>> c: +44 (0)778 946 1959
>> msn: [EMAIL PROTECTED]
>> gtalk: [EMAIL PROTECTED]
>>
>
--
Benjamin Nortier
e: [EMAIL PROTECTED]
c: +44 (0)778 946 1959
msn: [EMAIL PROTECTED]
gtalk: [EMAIL PROTECTED]
