Plan for comment nodes

short term

filter nodes passed to functions

long term

1. move all constructor args to be {}

a) do not use the constructor.. use
Element.create(args)
and
this.clone(newArgs)

where the implementations might look like

create: function(args) {
    foreach(var arg in args) {
        this[arg] = args[arg];
    }
    this.setup();
}
clone: function(args) {
    foreach(var arg in this) {
        this[arg] = args[arg];
    }
    this.create(args);
}

move code from the constructor that sets default properties e.g. isn't just this.a = a; into setup.

E.g.

function constructor() {
}
constructor.prototype.setup = function() {
    this.a = this.a === undefined ? true : this.a;
}

main point and benefit is that we can add properties to a node without breaking things and we can start to push location and whitespace information in at the base class level.

Alternative would be to make all nodes non prototypal objects - actually by moving functions to be static on the type I think we could move to this as a stage after this if we wanted..

b)
This allows us to implement in parser a function to create nodes.

createNode: function(type, args) {
    return type.create(args);
}

c)

This allows us to attach whitespace/comment/location information for each node

d)

We need a way for our Node base class to output comments automatically ? So one way would be rename genCSS to genCSSX and have genCSS implemented in Node, calling genCSSX after having output all pre-comments and post-comments

Alternatives

• add preComments / postComments to every constructor that needs it - problem is node constructors are unwieldy
• keep comments as nodes and keep solution to filter for functions. - problem is that visitors have to work-around having comments anywhere, is a bit hacky
• absorb comments and do not output them - how many css hacks will this effect?

Any more ideas welcome. Also need to decide if I/we do this if it constitutes a breaking change such that we need less v3

The issue names parser node construction, the Node base class, createNode, and genCSS, but no files or tests. Review those entry points and the listed alternatives first; the work is only done once a decided approach supports comment, whitespace, and location information without requiring visitors to filter comment nodes.