refactor: the Python code passes its own linter in strict mode

[JoshuaWink]

What

The Python code of this repository had 120 warnings from its own rule CUP-I008 (logic that is not in a primitive). This change resolves all of them, and CI now runs the invariant linter with --strict.

How each one was resolved

52 in the code itself

• 39 helper functions of the compiler Filters and of one lint Filter were functions at the top of their file. They are now static methods of the Filter that uses them. The logic is in the primitive.
• 7 private helpers of three syntax-tree visitors and one Hook are now methods of their class.
• The export pipeline was a function that built a Pipeline. It is now a named Pipeline, ExportPipeline. build_export_pipeline_v2 stays, and returns one.
• Three small decisions became tables: the severity of a rule, the prefix of a report line, and the fix text of a rule.
• The two lint_paths functions always put exclude, disable and strict in the first Payload. Before, each was added by an if.

68 with a comment that gives the reason

These are plain by design, and each has # cup: allow-plain <reason>:

What	Count	Reason
The primitives themselves (Payload, Pipeline, label_of)	3	The framework makes the primitives, so it is not written with them
Syntax-tree visitors	6	The tool that a Filter uses to read or change source code
Entries of programs, and what they use	6	They read arguments and print the result
The config reader	3	It runs before any pipeline exists
Shared helpers and records of the linter and compiler	6	Used by more than one Filter, or a record of data
The conformance runner	15	Test harness
The differential test harness (scorecard/)	29	Test harness

13 more comments are on conformance/run.py and conformance/bench.py (the judge and the speed check). They are not in the lint paths of cup.config.json, but the repository self-check covers them.

What keeps it this way

• CI: python -m codeupipe_lint.invariants --strict. A new warning fails the run.
• tests/lint/invariants/test_repo_is_clean.py now expects no finding and no warning. It also pins the number of allow-plain comments (81). A new comment changes that number, so a reviewer sees it.
• CUP-I009 reports a comment that allows nothing, so an old one cannot stay.

Checks

• Python tests: 521 pass, on Python 3.12 and 3.14.
• Conformance: 30 of 30 on each target, nothing unsupported.
• Speed check (Python 3.12): every number is within 25% of its baseline.
• Both linters report nothing, in strict mode.

Not in this change

• The TypeScript packages have 40 CUP-I008 warnings of their own. They are not touched here.

🤖 Generated with Claude Code