Exceptions in separate section

[sizmailov]

This PR splits Classes section in two: Classes and Exceptions.

[codecov]

Codecov Report

Merging #170 into master will increase coverage by 1.74%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master      #170      +/-   ##
===========================================
+ Coverage   98.25%   100.00%   +1.74%     
===========================================
  Files          27         1      -26     
  Lines        6647       353    -6294     
  Branches       44        44              
===========================================
- Hits         6531       353    -6178     
+ Misses        116         0     -116     

Impacted Files	Coverage Δ
plugins/m/components.py
plugins/dot2svg.py
plugins/m/link.py
plugins/m/qr.py
plugins/m/gl.py
plugins/m/alias.py
plugins/m/sphinx.py
plugins/m/plots.py
plugins/ansilexer.py
plugins/latex2svgextra.py
... and 15 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e6eff54...7778fed. Read the comment docs.

[sizmailov]

I've created a separate variable for exceptions. The alternatives of has_exceptions/has_classes variables or manual checks in templates look worse to me.

[mosra]

I'd actually keep them together in page.classes and branch in the template. That way people have more flexibility, either have them separate or put them sorted together with classes into a single "Classes" section in a modified template if they want.

[mosra]

I like this, except that I'd put exceptions together with classes into page.classes and then let people branch in the template (or not).

Assuming you wouldn't have time to get back to this project in the near future, I'll make the change when I get to merging this.

[mosra]

I'd actually keep them together in page.classes and branch in the template. That way people have more flexibility, either have them separate or put them sorted together with classes into a single "Classes" section in a modified template if they want.

[mosra]

Actually I don't know what to do with this. Attempted to merge this with the above-suggested modification, but halfway through I realized the distinction is done in module/class pages, but search shows both exceptions and classes as still classes, and then I'm not really sure if such distinction is actually that much important to be hardcoded this way, or whether this whole thing shouldn't be completely optional. And then there's dataclasses and generators and slots and shouldn't these also have a distinct treatment? Where to draw the line?

I get that right now the tool doesn't properly parse inheritance hierarchies and as such it's rather hard to see what's an exception and what not. However adding an is_exception property feels more like a hack to me than a real solution.

[sizmailov]

I don't have an answer for that. I did a minimal change that worked for my use case. I wanted separation of exceptions because of their lesser importance than regular classes in my specific library.
But you are right, it is not an universal pattern, someone might desire another grouping scheme...

It feels like moving branching to templates is the right direction. I think some new convenient properties/functions would help to avoid template code repetition and simplify it.