[Python-ideas] Proposal: New syntax for OrderedDict, maybe built-in

[David Wilson]

On Thu, Sep 04, 2014 at 07:35:06PM +0200, Norman Hooper wrote:

> I work with OrderedDict a lot, because JSON represents an OrderedDict
> and I need to work with JSON a lot.

ECMAScript:

    4.3.3 Object
    An object is a member of the type Object. It is an unordered
    collection of properties each of which contains a primitive value,
    object, or function. A function stored in a property of an object is
    called a method.

JSON:

    1. Introduction
    An object is an unordered collection of zero or more name/value
    pairs, where a name is a string and a value is a string, number,
    boolean, null, object, or array.


> With the ubiquity of JSON, it may also be time to promote OrderedDict
> to a built-in type too.

Neither JSON objects nor JavaScript object properties preserve
enumeration order. This is a common misconception since implementations
tend to preserve order when the number of keys is small, since they may
use a more efficient internal representation in that case, whose
enumeration order depends on order the properties were defined in.


David