comark/charts/x-in-y · Keep the x column out of y

x is the column the chart is drawn along, and y the columns it draws over it. A column can't be both, so the block shows the table alone.

Incorrect

::chart{x="pond" y="pond, ducks" title="Ducks per pond"}
| pond | ducks |
| --- | --: |
| north | 12 |
| south | 7 |
| east | 9 |
::

lint-comark example.mdexample.md:1:1 comark/charts/x-in-y::chart 1: column pond is both x and y.Remove it from y.✖ 1 problem

Correct

::chart{x="pond" y="ducks" title="Ducks per pond"}
| pond | ducks |
| --- | --: |
| north | 12 |
| south | 7 |
| east | 9 |
::

lint-comark example.md✔ No problems