Racket Coding Practices

Racket Coding Practices

Application skill for official Racket style learning (from the archived awesome-guidelines style capsules). Scribble and Typed Racket files follow guide exceptions noted in upstream docs.

Core Principle

Racket quality is DrRacket-readable text + explicit module contracts, kebab-case names, top-down provide sections, rackunit-guarded changes.

When to Use / NOT

• #lang racket libraries, HtDP/2htdp teaching code, PLT-style packages.
• Setting up DrRacket indent, rackunit, raco test, contract-out in CI.

NOT when:

• Generated .rkt from macros/tools, validate generators.
• Scribble-only layout rules, see Scribble exceptions in official guide.

Workflow

1. Textual, indent, parens, width (racket-style-formatting-textual.md).
2. Naming/constructs, kebab-case, define/cond/for (racket-style-naming-constructs.md).
3. Modules, provide, contracts, size (racket-style-modules-contracts.md).
4. Testing, rackunit, handlers (racket-style-testing-verify.md).
5. Verify, DrRacket indent-all, raco test on changed files.

Red Flags

• Tab characters
• Lines >102 without wrap (no file-local waiver)
• C-style closing paren on own line mid-form
• DrRacket indent-all changes file
• camelCase or snake_case identifiers
• Underscores in regular names
• Context-only cryptic abbreviations
• Nested if/begin where cond/match fits
• Heavy nested let where internal define works
• Long unnamed lambda bodies
• Macro where function works
• (provide (all-defined-out))
• provide blocks scattered at file bottom
• Missing purpose comment on exports
• Module >1000 lines without split plan
• Function >> screen height without decomposition
• Missing contract-out on public ADT modules
• Catch-all (lambda (_ #t) #t) handlers
• Bare exn? handler catching breaks
• Manual parameter save/restore vs parameterize
• Graphical syntax boxes in .rkt
• Plural collection module names
• Magic numbers without named constants
• Bug fix without rackunit regression
• No (module+ test …) on nontrivial new module
• Trailing whitespace
• Missing EOF newline
• Single ; where ;; section comment expected
• Graphical comment boxes breaking plain-text editors

Verification

• DrRacket "Indent All" leaves file unchanged (or documented exception at top)
• raco test path/to/changed.rkt (or package test suite)
• provide/contract-out audit on new exports
• Handler predicate precision review
• Capsule checklist on kebab-case + top-down module layout

References

• awesome-guidelines/references/racket-style-learning-note.md
• awesome-guidelines/references/racket-style-formatting-textual.md
• awesome-guidelines/references/racket-style-naming-constructs.md
• awesome-guidelines/references/racket-style-modules-contracts.md
• awesome-guidelines/references/racket-style-testing-verify.md