enh(asciidoc) Support level 5 sections

[il3ven]

Resolves #2868

Changes

Updated regexp for sections in src/languages/asciidoc.js

Before

begin: '^(={1,5}) .+?( \\1)?$'

After

begin: '^(={1,6})[ \t].+?([ \t]\\1)?$'

1. Section titles can contain ====== that is why changed (={1,5}) to (={1,6})
2. A = can be followed by a space or a tab. So, added [ \t].

Changes are based upon https://github.com/asciidoctor/asciidoctor/blob/697d7171830f3dc757175bc29b7eb528d4cdb4b5/lib/asciidoctor/rx.rb#L239

Checklist

• Added markup tests, or they don't apply here because...
• Updated the changelog at CHANGES.md
• Added myself to AUTHORS.txt, under Contributors

[joshgoebel]

I'm confused the site you linked to has (=={0,5}) and seems to indicate == is Level 1... oh I see they call = level 0. Ugh.

I'm not sure why they have the 0... since is a line really a title without any ====? But given their rule it would seem that

========== (== * 5)

Is also a possibility, no?

[joshgoebel]

The examples on their doc site seem to contradict the whole =={0,5} also... so frustrating.

[il3ven]

========== (== * 5) Is also a possibility, no?

No.

I think the regular expression =={0,5} means that after a = there can be 0 to 5 = signs.

====== is a valid section as in this case = is followed by 5 =. However, ======= is not a valid section as the = is followed by 6 =.

I think a reason they used =={0,5} instead of ={1,6} is to differentiate sections from document title.

= Document Title (Contains a single = )

[ggrossetie]

Thanks @il3ven for taking care of it.

You got it right.
= Document Title is a document title not a section title.

The examples on their doc site seem to contradict the whole =={0,5} also... so frustrating.

It's two equal signs (==) followed by 0 up to 5 equal signs.
So effectively between == (2 equal signs) and ====== (6 equal signs).

[joshgoebel]

I think the regular expression =={0,5} means that after a = there can be 0 to 5 = signs.

It totally does, and I know that. To group the == you'd need (==) of course. That whole == is just infuriating and confusing and totally throwing me off. :-)

I think a reason they used =={0,5} instead of ={1,6} is to differentiate sections from document title.

=={0,5} and ={1,6} have exactly the same behavior. I can't see any reason to prefer == so I have no idea why they chose to write it that way.

= Document Title is a document title not a section title.

I don't think we care, it'll still match as a "section" for us, no?

It's two equal signs (==) followed by 0 up to 5 equal signs. So effectively between == (2 equal signs) and ====== (6 equal signs).

Nope.

=                 A single = 
={0,5}          0 to 5 =s

A single equal, followed by 0-5 more... otherwise known to normal people as "1-6 equals" LOL.

So = would match.

[ggrossetie]

Ah ah ah I got tricked 😬

So = would match.

On second thought, you can have section title level 0 (i.e., a single =) when using a book doctype.
Maybe the reasoning was to match the AsciiDoc definition, you can have level 0 to level 5 section titles.