bson (by spec?) orders elements; this implementation doesn't define order of elements

[tcoram]

trafficstars

Need to look closer at spec and see what it takes to order elements.

[dptole]

What order the elements is the binary string itself but, in my opinion, the order don't matter because some languages just force a specific sorting of the elements of an array, leaving no option to the developer.

Lua does but JavaScript don't, so I think it's up to the community to take care of that, even though I think it is not an important issue.

[LinusU]

@dptole I cannot possibly think of any language that forces a specific sorting of arrays, mind elaborating a bit?

a = {}

a[1] = "a"
a[2] = "b"
a[3] = "c"

"b" will always be at position 2, the language doesn't force any sorting here?

[dptole]

@LinusU sorry, I didn't express myself well In Lua we don't have arrays or objects as in JavaScript or others, there is just tables which maps any value to any value. If you have a table that looks like an array you can change the values of the already defined indexes and the language will not reorder the array for you.

> a = {1,2,3}
> for k, v in pairs(a) do print(k,v) end
1    1
2    2
3    3
> a[2] = 'foo'
> for k, v in pairs(a) do print(k,v) end
1    1
2    'foo'
3    3

But if you have a table that looks like an object then we start getting strange behaviours.

> a = {lua = 'moon', terra = 'earth', marte = 'mars'}
> for k, v in pairs(a) do print(k,v) end
marte   mars
lua     moon
terra   earth -- It was not displayed the way I defined
> a[1] = 'pluto' -- Strange but possible
> for k, v in pairs(a) do print(k,v) end
marte   mars
1       pluto -- I think this item should not appear here
lua     moon
terra   earth

-- Now let's insert them one by one

> a={lua = 'moon'}
> for k, v in pairs(a) do print(k,v) end
lua     moon -- OK
> a['terra'] = 'earth'
> for k, v in pairs(a) do print(k,v) end
lua     moon
terra   earth -- Nice
> a['marte'] = 'mars'
> for k, v in pairs(a) do print(k,v) end
marte   mars
lua     moon
terra   earth -- Lost the order

If we have an issue about the order of the elements and the language has this behaviour we would have to do a little more work to implement something that, in my opinion again, it is not important at all. At least not now.