Add extra hanging indentation after a word-wrap to account for lists

[eugenesvk]

Problem description

(for example) In markdown it's common to have lists that can span multiple lines. Soft-wrapping allows you to still see the overflowing text. However, soft-wrapping doesn't account for the width of the list markers (for example, 11. or 12. for a numbered list below), so it looks a bit more ugly then necessary

11. list with a long line...
...continued currently from the beginning of a line, not the beginning of the text
12. next item
↑ wrong   soft-wrap without hanging indentation accounting for the width of the list indicator
↓ correct soft-wrap with        ↑...↑
11. list with a long line...
    ...continued with a hanging indent, whose width equals to the width of `11.`
12. next item, note the nice text alignment

Preferred solution

Ideally there should be a flexible API that would allow the user/plugin/syntax author to set a combination of

• a regex
  e.g. ^\s*\d*\. to match 11. and 12.
  (similar to formatlistpat in vim)
• hanging indent width (fixed number or the width of the starting regex matching group number/name e.g., -1 to set the width to =1. for the single digit list items and =11. for the double digit list items
  (similar to breakindentopt in vim)
• a list of syntax scopes
  e.g. text.html.markdown markup.list.numbered.markdown meta.paragraph.list.markdown -markup.raw.code-fence.markdown-gfm (last one excludes fenced code from this)
  (doesn't exist in vim)

I think this should allow enough flexibility to cover most use cases(hopefully?) So you could change hanging indents in regular text vs embedded source code in markdown vs non-embedded source code etc.

Alternatives

As far as I understand, plugins can't do that, so no good alternatives exist (hard-wrapping is awful, so not an alternative)

Additional Information

This was mentioned in multiple places, at least in this package SublimeText-Markdown/MarkdownEditing#42
As far as I understand it, there are still no Sublime Text Core APIs that would allow even plugin authors to achieve this

[deathaxe]

Related with #2356