R Style Enforcer

Detects LLM code smells in R scripts and rewrites them to match the user's personal coding style, with archive-verify-revert safety. This is a post-production skill — use it only after the analysis is complete and outputs are verified. Do NOT use it while first writing or debugging scripts; the verbose LLM patterns (status printing, tryCatch, etc.) are useful during development. This skill is for making finished code readable to humans.

Constraints

NEVER:

• •Use this skill during initial development or debugging — LLM patterns (verbose output, tryCatch, etc.) are useful while building; this skill is only for post-production cleanup
• •Change statistical logic, model specifications, or results
• •Remove code that affects output (only remove style/presentation artifacts)
• •Auto-rewrite when outputs cannot be verified — hand off instead
• •Introduce new packages not already loaded
• •Touch quote style, pipe style (%>% vs |>), ifelse() vs if_else(), or across() vs mutate_at()

MUST:

• •Archive original to <filename>_llm_draft.R before any changes
• •Capture output from the original version before editing
• •Verify rewritten version produces identical output
• •Revert from archive if outputs diverge, reporting what differed
• •Flag ambiguous transformations for user review (see escalation policy)
• •Use <- for assignment exclusively
• •Include explicit return() in every function
• •Prefer purrr::map() and friends when purrr/tidyverse is loaded — do NOT convert purrr to lapply
• •Search the entire project for callers (grep -r "function_name") before classifying any function as single-use
• •Commit with git after each transformation step, using succinct 2-3 sentence commit messages
• •Move archived files into a .drafts/ subfolder (not alongside the working files)

CAN:

• •Rename variables (SCREAMING_SNAKE_CASE → snake_case, verbose → concise)
• •Strip verbose cat() / status printing / emoji checkmarks
• •Remove template headers, "End of Script" markers, over-documentation
• •Inline unnecessary abstractions (only after confirming single-use via project-wide grep)
• •Add substantive comments where logic is non-obvious and no comment exists (explain WHY, not WHAT)

Escalation Policy

Proceed automatically when:

• •Removing boilerplate (template headers, "End of Script", ASCII dividers, emoji checkmarks, "Step N:" narration, "Next step:" signposts, "Author:" attribution)
• •Renaming SCREAMING_SNAKE_CASE to snake_case
• •Stripping verbose cat() output
• •Removing Roxygen on non-package functions
• •Removing "ABSTRACTION NOTE" comments
• •Dropping data_ prefixes
• •Fixing = assignment to <-
• •Adding explicit return()
• •Inlining functions confirmed single-use by project-wide grep

Flag for user when:

• •Removing tryCatch that protects genuinely risky operations (file I/O, network)
• •Collapsing multiple files into one
• •Changing code logic beyond pure style
• •Removing a utility file or test file
• •Splitting or joining scripts (see scope rules in references/style-guide.md §I)

Hand off to user when:

• •Verification fails (outputs differ)
• •Structural reorganization needed (changing file dependencies)
• •Genuine bugs discovered (report but don't fix)
• •Scripts that can't be verified (long-running, external dependencies)

Workflow

1. •Read the complete R script
2. •Identify LLM smells using the detection table and references/smell-catalog.md
3. •Search the entire project for function/variable usage before classifying anything as single-use
4. •Classify each transformation: auto-rewrite, flag, or hand-off per escalation policy
5. •Evaluate script scope: check if the script should be split (too many responsibilities) or joined with another (see references/style-guide.md §I)
6. •Archive: Create .drafts/ subfolder if it doesn't exist; copy original to .drafts/<filename>_llm_draft.R
7. •Git commit: Commit the archive with message: "Archive LLM draft of <filename> before restyling"
8. •Capture baseline: Run original, identify and capture key output objects per references/verification.md
9. •Rewrite using rules from references/style-guide.md and patterns from references/smell-catalog.md
10. •Git commit: Commit rewritten file with message describing transformations applied (2-3 sentences)
11. •Verify: Run rewritten version, compare outputs per references/verification.md
12. •If match → done. Git commit confirming verification passed.
13. •If mismatch → revert from .drafts/ archive, git commit the revert, report discrepancies, hand off to user
14. •Report: list all transformations applied, any flagged items, and verification result

Detection Table

Quick Reference

• •Assignment: <- always, never =
• •Returns: explicit return() in every function
• •Iteration: prefer purrr::map() when tidyverse is loaded; leave existing purrr/lapply as-is
• •Naming: snake_case; concise readable names; no SCREAMING_SNAKE_CASE
• •Headers: 1-3 lines explaining what the script does, not a template
• •Comments: Full sentences explaining WHY, not narrating WHAT; plenty of them
• •Console: Minimal; message() for genuinely useful info, no emoji/boxes/narration
• •Scope: One responsibility per script; split bloated scripts, merge redundant ones (flag for user)
• •Git: Commit at each stage (archive, rewrite, verify) with succinct messages
• •Archives: .drafts/ subfolder, never alongside working files
• •Don't touch: quote style, pipe style, ifelse vs if_else, across vs mutate_at, lapply vs map