Highlight Lines (hl_lines) didnt match up with Line Numbers (linenums)

[SPyofgame]

Context

AFAIK lines_num will change the first index of the code block (which is by default 1) to another higher positive integer.

I expect hl_lines will be relative to the lines_num, but instead, it will just ignore the lines_num which might sometimes be confusing to a new user (e.g: new writer joining my project)

Issue Description

For example I have the code like this

    ```cpp  linenums="6"
    /// Ham tinh quy hoach dong tong tap con | a[0..n-1] voi n = 2^k
    vector<long long> dp_sos(const vector<int> &a, const int n)
    {
        /// Khoi tao mang
        vector<long long> F(n, 0LL);

        /// Duyet qua cac trang thai mask
        for (int mask = 0; mask < n; ++mask) /// O(2^n)
        {
            /// Tinh F[mask] = Sigma(submask) a[submask]
            /// Bai toan khong can tinh a[0] thi gan submask = 1
            for (int submask = 0; submask < n; ++submask) /// O(2^n)
            {
                /// Neu nhu submask la tap con cua mask
                if ((mask & submask) == submask)
                {
                    /// Tinh tong tap con hien tai
                    F[mask] += a[submask];
                }
            }
        }

        return F;
    }
    ```

for which will be rendered as

adding the specific highlights linenums="6" hl_lines="13 17 20" which will intendedly to do something like this

instead, the result is a bit different

Suggestion:

Though I would not say it is demanding as I think this is a niche unworthy work that needs not and should not to be prioritized. But if you are interested, I have some ideas that you might wanna expand:

Relative Highlight: Using hl_relines for highlight relative lines, that will minus the linenums for relative

Code Wrappers: Wrap a bunch of code that allows the user to toggle collapsible wrap = 4-10 12-15 21-47 70-85

Range RelativeHighlight: hl_relines = 4-10 14-19 stuff for a sufficiently long code.

Dimish Unimportant: To get rid of those unimportant parts with a shady darker brightness dimish = 10-16

Mouse Coordination: To know the current position of the mouse on the code (Row, Column) with a vertical and horizontal highlight coord=true/false

Code Pointer: Toggle for the user to be able to move around the code using arrows keys pointer=true/false

Hover Note: Like code annotation, but specifies note on sideways upon hovering hover = A[10-20] B[50-60] then A: <def> then B: <def>. This will allow the user to get the simple note and its references for confusing parts of the code (tho it seems rarely we need this over the admonition, eg: code that shouldn't add anything extra like comments).

Minimal Base Yaml

image: python:latest
pages:
  stage: deploy
  script:
    - pip install git<private link>
    - mkdocs build --site-dir public
  artifacts:
    paths:
      - public
  rules:
    - if: '$CI_COMMIT_BRANCH == $CI_DEFAULT_BRANCH'

  features:
    - content.code.select
    - content.code.copy

markdown_extensions:
  - pymdownx.highlight:
      anchor_linenums: true
      use_pygments: true
      auto_title: true
      linenums: true
      linenums_style: pymdownx-inline
      pygments_lang_class: true
      line_spans: __span
  - pymdownx.inlinehilite
  - pymdownx.snippets
  - pymdownx.superfences

Related Links

https://squidfunk.github.io/mkdocs-material/reference/code-blocks/?h=hl+lines#highlighting-specific-lines
https://facelessuser.github.io/pymdown-extensions/extensions/superfences/?h=hl_lines#highlighting-lines

Browser

Chrome

Before Startings The Discussions

• I have search for similar discussions
• I have attached links to the documentation, and possibly related issues and discussions.
• I assure that I have removed all customizations before submitting this bug report.

[facelessuser]

The Material theme does control this. I believe this would be a request for https://github.com/facelessuser/pymdown-extensions.

hl_lines highlights the line you tell it to. linenums is a cosmetic change making the line numbers visible and allowing you to remap them relative to some new start.

This is definitely not a bug but works as intended. Now, it may be that it is desired that enhance this with an optional setting, if so, feel free to create a feature request over at Pymdown Extensions. I'll have to make a decision on whether to add the feature, but I'd at least get an issue created if you are really wanting it.

[SPyofgame]

In my opinion, having both absolute and relative is useful for many cases. But I am just afraid that you might gotta end up with more maintenance costs (eg: blended hl_lines and hl_relines might also cause certain issues under certain customizations or incompatibilities). So I will leave those as suggestions instead of issues (tho I really want it 🥺 )

But I just also notice something, how can I have this Toogle Line Detection, seems like Mouse Coordination I mentioned earlier

Are there other optional features that I can enable (with certain plugins, features, customizations, ... ?)

[squidfunk]

The feature is called code selection:

theme:
  features:
    - content.code.select

[SPyofgame]

I just find out the Hover Note suggestion feature kinda looks like this How to set tooltips for code blocks?

[SPyofgame]

The feature is called code selection:

theme:
  features:
    - content.code.select

Oh, so my suggestion had been already implemented (just without an extra column highlight) right 👍 Thank you.