code-review

name	code-review
description	Perform a thorough Rust code review on the BuildLang compiler
tools	Read, Grep, Glob, Bash(git diff:*, cargo:*)

Code Review Skill (Rust / BuildLang)

You are reviewing Rust code for the BuildLang compiler project. This is a multi-phase compiler with lexer, parser, type checker, and code generator stages.

Trigger

User asks to review code, a PR, or recent changes.

Process

1. Gather Context

• Run git diff HEAD or git diff --cached to see changes
• Run git log --oneline -5 to understand recent work
• Identify which compiler phase(s) the changes affect

2. Review by Priority

P0 - Safety & Soundness

• No unjustified unsafe blocks
• No undefined behavior (UB)
• No unsound type coercions in the type checker
• Error handling uses Result/?, not .unwrap() in lib code
• No panics in code paths reachable by user input

P1 - Correctness

• Pattern matches are exhaustive (no catch-all _ hiding bugs)
• Lifetime annotations are correct
• AST visitors handle all node types
• Parser error recovery doesn't skip important tokens
• Code generation output matches language semantics

P2 - Performance

• No unnecessary String allocations (use &str or Cow)
• No unnecessary .clone() calls
• Iterator chains preferred over indexed loops
• Large enums use Box for variant data where appropriate
• No O(n^2) algorithms where O(n) or O(n log n) would work

P3 - Idiomatic Rust

• Result/Option used properly (no sentinel values)
• Traits designed for extensibility
• Derive macros used where appropriate (Debug, Clone, PartialEq)
• impl Display for user-facing types
• Public APIs have /// doc comments

P4 - Maintainability

• No dead code
• Clear naming conventions
• Files <= 500 lines
• Functions <= 60 lines
• Related code grouped into modules

3. Output Format

## Code Review: [summary of what was reviewed]

### Critical (must fix before merge)
- File:line - Issue - Fix

### Warnings (should fix)
- File:line - Issue - Fix

### Suggestions (nice to have)
- File:line - Issue - Fix

### Looks Good
- [List of things done well]

**Verdict: APPROVE | REQUEST CHANGES | NEEDS DISCUSSION**