Allow specifying custom clause numbers

[nicolo-ribaudo]

Some proposal authors prefer writing proposals using the same section numbers as ecma262, but it requires hacks.

This PR allows specifying a custom number="..." attribute for emu-clause nodes.

• for nested clauses, you can only specify the last number segment: the first ones are always inherited from the parent clause
• after a custom number, automatic numbering continues from that number and not from where it left. This means that <emu-clause /> <emu-clause number="8" /> <emu-clause /> gives 1, 8, 9 and not 1, 8, 2 or 1, 8, 3.

cc @ljharb

[ljharb]

Yay!

[bakkot]

Thanks! I pushed a commit adding support for nested numbers, as in number="1.1", as well as a few more warnings for error cases.

[bakkot]

Released in 14.1.0.

[nicolo-ribaudo]

Thank you!

[ljharb]

This is great, and works perfectly! I’ve cleaned up 3 proposals so far.