add: Counter

[metaist]

I generally like the way that CSS Counter Styles 3 works, but I don't think I need most of that functionality.

• name: yes
• system: no; just give me a .render function instead
• negative: no; I only have non-zero positive numbering
• prefix / suffix: maybe; for now I just need .value or (value)
• pad: no; just change your .render
• range / fallback: no; I don't have limited range
• symbols / additive-symbols: no; I don't support this style
• speak-as: interesting, but not relevant for my use case

[metaist]

So... mostly I'll borrow the naming and meaning from the Predefined Counter Styles.

[metaist]

When registering a Style, I should probably raise an exception if it's already been registered. (And then I need an override=True to let me do it anyway.)

[metaist]

So .up() increments the current level. What if there are no levels? Should that raise an exception?

Probably not for now, but something to consider.

[metaist]

So it looks like I have two different kinds of "styles": numeral systems and formatting. And for "formatting" there are two kinds of display: the full citation (when making a reference) and the definition format.

[metaist]

After much back-and-forth, I think I finally have it in a basic form I like. Levels and References are both Ref objects with slightly different purposes. The former manages which kind of section we're in an how things get formatted (via .push()) while the latter controls how we reference this specific location (via .up()).

This is definitely different that the CSS 3 Counter Styles in many ways.

[metaist]

I'm reading the W3C spec for Counters to see if there's anything from there worth implementing.