Complexity reduction

.claude/settings.local.json

@@ -98,7 +98,13 @@
       "Bash(cargo search *)",
       "Bash(cargo add *)",
       "Bash(cargo tree *)",
-      "Bash(curl -s https://crates.io/api/v1/crates/arrow/__TRACKED_VAR__.0.0)"
+      "Bash(curl -s https://crates.io/api/v1/crates/arrow/__TRACKED_VAR__.0.0)",
+      "Bash(.venv/Scripts/xenon src/ --max-average B --max-modules C --max-absolute D)",
+      "PowerShell(.venv/Scripts/python -m pytest tests/output/test_emit_render_block.py -x -q 2>&1)",
+      "PowerShell(.venv/Scripts/python -m pytest tests/dictionary/test_schema.py -x -q 2>&1 | Select-Object -Last 5)",
+      "PowerShell(.venv/Scripts/python -m pytest -q --tb=short 2>&1 | Select-Object -Last 5)",
+      "PowerShell(.venv/Scripts/python -m radon cc src/cifflow/dictionary/schema.py --show-complexity --min C 2>&1)",
+      "PowerShell(.venv/Scripts/python -m xenon src/ --max-average B --max-modules C --max-absolute D 2>&1)"
     ]
   }
 }

CLAUDE.md

@@ -222,6 +222,18 @@ Ingest a known-good file, emit, re-ingest, compare. `second.cif` is the primary
 Load `cif_pow.dic` via `DictionaryLoader`, call `generate_schema`, call
 `apply_schema`. See `tests/ingestion/test_integration.py` for the reference pattern.
 
+### Complexity analysis
+```
+# Show all functions rated C or worse (the refactoring backlog)
+.venv/Scripts/python -m radon cc src/ --show-complexity --min C
+
+# Enforce thresholds (exits non-zero if any module averages above B,
+# any function exceeds C, or any block exceeds D)
+.venv/Scripts/xenon src/ --max-average B --max-modules C --max-absolute D
+```
+Grade scale: A ≤5, B 6–10, C 11–15, D 16–25, E 26–50, F 51+.
+Target: no F or E functions; D functions should have a documented reason.
+
 ---
 
 ## Checklist Before Any Change

pyproject.toml

@@ -31,6 +31,8 @@ dev = [
     "bump-my-version",
     "ruff>=0.4",
     "pydoclint[flake8]>=0.4",
+    "radon>=6.0",
+    "xenon>=0.9",
 ]
 docs = [
     "mkdocs>=1.6",
@@ -97,3 +99,6 @@ convention = "numpy"
 [tool.pydoclint]
 style = "numpy"
 arg-type-hints-in-docstring = false
+
+[tool.radon]
+exclude = "tests/*"