refactor: Update expression checker to use new diagnostics

[mark-koch]

Closes #539

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 92.85714% with 15 lines in your changes missing coverage. Please review.

Project coverage is 91.89%. Comparing base (bf60207) to head (c56c7c8).

Files with missing lines	Patch %	Lines
guppylang/checker/expr_checker.py	92.78%	15 Missing ⚠️

Additional details and impacted files

@@               Coverage Diff                @@
##           diag/jupyter     #587      +/-   ##
================================================
+ Coverage         91.70%   91.89%   +0.18%     
================================================
  Files                61       61              
  Lines              6511     6675     +164     
================================================
+ Hits               5971     6134     +163     
- Misses              540      541       +1     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[doug-q]

Nice.

I would prefer putting sub-diagnostics logic inside the Error classes rather than have callers explictly add_sub_diagnostic, but if you prefer it this way that's fine.

[doug-q]

This one seems to duplicate the one above and It doesn't seem to be used?

[doug-q]

This seems unrelated?

[mark-koch]

Yeah this is a drive by to fix a bug in one of the Jupyter notebook tests: source only holds the source of the function definition, but the line numbers in the AST correspond to the whole cell

[mark-koch]

I would prefer putting sub-diagnostics logic inside the Error classes rather than have callers explictly add_sub_diagnostic, but if you prefer it this way that's fine.

I prefer the current design since some sub diagnostics are only added conditionally (e.g. notes on linearity errors). But I agree, it would be nice to have a pattern for sub diagnostics that are always added. I created issue #620 to implement this